Nutrition & Vitamins

Nutrition & Vitamins, Liver & Kidney Health

Twenty-four hour urine collection to measure protein loss is helpful in work-up of some patients with hypoalbuminemia. Other testsuseful in assessment of nutritional statusinclude TIBC, transferrin, iron, absolute lymphocyte count, and vitamin B12/folate levels.

Liver & Kidney Health, Nutrition & Vitamins

Drug effects have been summarized.10

Blood Disorders, Nutrition & Vitamins

Offered as part of multiple lab tests

Nutrition & Vitamins

Increasing dietary intake of potassium has been reported to increase serum phosphate concentrations apparently by decreasing renal excretion of phosphate.10During the last trimester of pregnancy there is a sixfold increase in calcium and phosphorus accumulation as the fetus triples its weight. Plasma phosphorus concentrations may provide a useful means to assess response to phosphate supplements in the premature infant.11

Nutrition & Vitamins, Bone Health

In the differential diagnosis of hypercalcemia serum calcium should be measured on at least three occasions. Inprimary hyperparathyroidism(HPT) parathyroid hormone, serum chloride, and urine calcium are increased. Rarely, in HPT the hypercalcemia is accompanied by a low-normal PTH.8In HPT, calcium rises, then phosphorus falls, then alkaline phosphatase rises. Alkaline phosphatase is usually not more than twice its upper limit in HPT. Measured ionized calcium and calculated ionized calcium may be helpful.Twenty-four hour urinary calcium is increased in HPT, low infamilial hypocalciuric hypercalcemia(FHH) which is characterized by hypercalcemia and hypocalciuria. An autosomal dominant, it apparently has no complications. A ratio of renal calcium clearance:creatinine clearance <0.01 suggests this genetic disease. The calcium:creatinine clearance ratio is said to discriminate between FHH and hyperparathyroidism.2Family studies are highly desirable.Hypocalcemia, then hypercalcemia occur with rhabdomyolysis − induced acute renal failure.9,10

Nutrition & Vitamins, General Health & Wellness

Like other electrolytes, chloride cannot be interpreted without clinical knowledge of the patient. A diagnostic approach to the evaluation of hyperchloremic metabolic acidosis includes use of the urinary anion gap in conjunction with measurement of plasma potassium and urinary pH.1

Nutrition & Vitamins, General Health & Wellness

Parathormone enhances tubular reabsorption of magnesium. Measure magnesium in patients with hypocalcemia, of whom 23%, without renal failure, were found in one study to have hypomagnesemia.2Magnesium containing drugs can cause toxic levels in patients with impaired renal function. A causal relation between decreased Mg2+content of cardiac muscle/coronary arteries and nonocclusive sudden-death ischemic heart disease has been proposed. Serum magnesium constitutes only a small fraction of total body stores and may not predict magnesium status correctly.7Magnesium acts as a metallic cofactor in over 300 enzymatic reactions.8A positive correlation between normomagnesemia and successful resuscitation is reported.9Serum magnesium has prognostic importance in congestive heart failure.10

Blood Disorders, Nutrition & Vitamins

Ferritin is found in virtually all cells of the body and serves as the cellular storage repository for iron.2,3Ferritin is a macromolecule with an average molecular weight of near 440 kD that varies depending on the iron content. Ferritin consists of a protein shell (apoferritin) of 24 subunits surrounding an iron core consisting of up to 4000 ferric iron ions. The majority of ferritin iron stores are found in the liver, spleen, and bone marrow. Ferritin is present in small concentration correlates with total-body iron stores, making its measurement valuable for the assessment of disorders of iron metabolism.Low levels of ferritin can be found when iron stores are exhausted, well before the serum iron level has become affected. In the setting of anemia, low serum ferritin is a very specific biomarker for iron deficiency anemia. In fact, there is no clinical situation other than iron deficiency in which extremely low values of serum ferritin are seen; however, some clinical states involving infection or inflammation can cause the ferritin level in the serum of patients with iron deficiency to increase into the normal range. Ferritin is an acute-phase reactant that is thought to play a role in the body's defense against oxidative stress and inflammation. Increased ferritin values can also be observed in malignant disease, including acute leukemia; Hodgkin's disease; and carcinoma of the lung, colon, liver, and prostate. Consequently, serum ferritin in the normal range reflects iron sufficiency only in the absence of these conditions.Patients with a serum ferritin concentration below the lower limit of the reference interval have a very high probability of being iron deficient; however, given the low sensitivity of a low ferritin level (below the lower limit of normal), a higher ferritin cutoff may be more appropriate for screening for potential iron deficiency in some populations.4-7It is exceedingly uncommon for ferritin levels to exceed 100 ng/mL in patients with iron deficiency.6,7An elevated ferritin level can result from iron overload due, in part, to increased hepatic ferritin synthesis.8Iron overload can occur in hemochromatosis, other excess iron storage disorders, and in individuals who have received multiple blood transfusions. Ferritin can also become markedly elevated secondary to obesity, chronic alcohol consumption, steatohepatitis, chronic inflammation, viral hepatitis, and malignancy. The increased prevalence of obesity has likely resulted in the increased incidence of ferritin elevations, as fatty liver may be the most common cause of an elevated serum ferritin.8Clinical assessment is required to determine whether the serum ferritin elevation is related to hemochromatosis or another underlying liver disease.9To confirm the diagnosis of hemochromatosis, other iron tests (iron, TIBC), and genetic testing may be performed.

Nutrition & Vitamins

Offered as part of multiple lab tests

Blood Disorders, Nutrition & Vitamins

Reticulocytes stained with a fluorescent reagent can be differentiated from mature red cells and other cell populations by light scatter, direct measurements, and opacity characteristics when using an automated hematology analyzer equipped with reticulocyte counting technology.

Blood Disorders, Nutrition & Vitamins

Serum iron is increasedin hemosiderosis, hemolytic anemias especially thalassemia, sideroachrestic anemias, hepatitis, acute hepatic necrosis, hemochromatosis, and with inappropriate iron therapy. Iron may reach high levels with iron poisoning. Some patients who receive multiple transfusions (eg, some hemolytic anemias, thalassemia, renal dialysis patients) will have increased serum iron levels.Serum iron is decreasedwith insufficient dietary iron, chronic blood loss (including the hemolytic anemias paroxysmal nocturnal hemoglobinuria), inadequate absorption of iron and impaired release of iron stores as in inflammation, infection and chronic diseases. The combination of low iron, high TIBC and/or transferrin and low saturation indicates iron deficiency. Without all of these findings together, iron deficiency is unproven.2Low ferritin supports the diagnosis of iron deficiency.Detection of iron deficiency may lead to detection of adenocarcinoma of gastrointestinal tract, a point which cannot be overemphasized.In recovery from pernicious anemia, especially just after B12dose, iron levels are low. In fact, the drop in serum iron 1 to several days after the Schilling test flushing dose of vitamin B12may be more useful in diagnosis than the radioactivity of the 24-hour urine collection. Serum iron is reported to drop with acute infarct of myocardium.TIBC is increasedin iron-deficiency, use of oral contraceptives, and in pregnancy.TIBC is decreasedin hypoproteinemia due to many causes, and is decreased in a number of inflammatory states.Increased saturationoccurs with HLA-related (classical) hemochromatosis before ferritin is greatly increased, and also with iron overload (eg, cirrhosis and portacaval shunt), in hemolytic anemias and with iron therapy. Saturation >70% in females, >80% in males is described as prerequisite for parenchymal loading; however, sample contamination and the vagaries of fluctuation in serum iron levels can make such criteria misleading on occasion.2The serum ferritin is a more sensitive test than the serum iron or TIBC for iron deficiency and for iron overload.2When all these tests are used together, as is often necessary, they usually can distinguish between iron deficiency anemia and the anemia of chronic disease. The best and most reliable evaluation of total body iron stores is by bone marrow aspiration and biopsy. The best evaluation of iron deficiency in childhood (unless lead toxicity is suspected) is free erythrocyte porphyrins.With recombinant erythropoietin therapy serum iron, transferrin saturation, and ferritin levels decline due to rapid utilization by stimulated erythropoiesis with resultant decrease in storage iron.3,5While iron is usually considered in relation to hematopoiesis and oxygen transport functions of red cells, it is also of prime import to the lymphomyeloid systems.6

Liver & Kidney Health, Nutrition & Vitamins

Even mild renal failure decreases uric acid excretion. Uric acid excretion is decreased with hypertension.A young patient with acute gouty arthritis, uric acid stones, and any patient who excretes >1000 mg uric acid/24 hours, should be evaluated for HPRT deficiency.2The uric acid:creatinine ratio has been used as a test for Lesch-Nyhan syndrome (HPRTase deficiency). Normal control patients 0.21−0.59; partial enzyme deficient group 0.62−2.00; complete enzyme deficiency 1.98−5.35.3The ratio of uric acid:creatinine in morning samples of urine has been used as a test for detection of the Lesch-Nyhan syndrome, which is associated with virtually complete absence of activity of the enzyme hypoxanthine-guanine phosphoribosyltransferase. This ratio has also been applied to 24-hour urine samples from adult patients with gout for detection of partial deficiency of the same enzyme. The uric acid:creatinine ratio in the urine of normal control patients is reported to range from 0.21−0.59. Patients with gout exhibit ratios of 0.15−0.73, whereas those patients with hyperuricemia associated with another disorder such as leukemia or glycogen-storage disease have ratios of 0.25−1.77. The ratio is 0.27−0.58 for patients with nongouty arthritis. Patients with complete hypoxanthine-guanine phosphoribosyltransferase deficiency are reported to have urinary uric acid:creatinine ratios of 1.98−5.35, as compared to 0.62−2.00 for patients with gout accompanied by partial enzyme deficiency.The ratio of uric acid:creatinine concentration on a random urine specimen has also been shown to be >1.0 in patients with acute renal failure secondary to acute uric acid nephropathy, but <1.0 in patients with acute renal failure resulting from other causes.

Nutrition & Vitamins

Folates are compounds of pteroylglutamic acid (PGA) that function as coenzymes in metabolic reactions involving the transfer of single-carbon units from a donor to a recipient compound. Folate, with vitamin B12, is essential for DNA synthesis, which is required for normal red blood cell maturation.2Humans obtain folate from dietary sources including fruits, green and leafy vegetables, yeast, and organ meats.3Folate is absorbed through the small intestine and stored in the liver.Low folate intake, malabsorption as a result of gastrointestinal diseases, pregnancy, and drugs such as phenytoin are causes of folate deficiency.4Folate deficiency is also associated with chronic alcoholism.5Folate and vitamin B12deficiency impair DNA synthesis, causing macrocytic anemias. These anemias are characterized by abnormal maturation of red blood cell precursors in the bone marrow, the presence of megaloblasts, and decreased red blood cell survival.2Since both folate and vitamin B12deficiency can cause macrocytic anemia, appropriate treatment depends on the differential diagnosis of the deficiency. A serum folate concentration <3 ng/mL is considered to represent clinical deficiency by the World Health Organization and numerous subsequent clinical studies.6,7Serum folate measurement provides an early index of folate status3; however, folate is much more concentrated in red blood cells than in serum so the red blood cell folate measurement more closely reflects tissue stores.5,8Erythrocytes incorporate folate as they are formed, and levels remain constant throughout the life span of the cell. RBC folate levels are less sensitive to short-term dietary effects than are serum folate levels. Red blood cell folate concentration is considered the most reliable indicator of folate status.3Low serum folate during pregnancy has been associated with neural tube defects in the fetus.9,10In the 1990s mandatory increased fortification of enriched cereal-grain products along with the requirement of folate-related health and nutrient content claims on food and dietary supplement products significantly increased the folic acid content of the US food supply.11-13Several reports have shown that serum folate concentrations have increased in the general US population since these measures were implemented.11-13

Nutrition & Vitamins, Blood Disorders

Vitamin B12, or cyanocobalamin, is a complex corrinoid compound containing four pyrrole rings that surround a single cobalt atom.2Humans obtain vitamin B12exclusively from animal dietary sources, such as meat, eggs, and milk. Vitamin B12requires intrinsic factor, a protein secreted by the parietal cells in the gastric mucosa, for absorption. Vitamin B12and intrinsic factor form a complex that attaches to receptors in the ileal mucosa, where proteins known as transcobalamins transport the vitamin B12from the mucosal cells to the blood and tissue.3,4Most vitamin B12is stored in the liver as well as in the bone marrow and other tissues.Vitamin B12and folate are critical to normal DNA synthesis, which in turn affects erythrocyte maturation.3,5,6Vitamin B12is also necessary for myelin sheath formation and maintenance.7The body uses its B12stores very economically, reabsorbing vitamin B12from the ileum and returning it to the liver so that very little is excreted.4,8Clinical and laboratory findings for B12deficiency include neurological abnormalities, decreased serum B12levels, and increased excretion of methylmalonic acid.4,8,9The impaired synthesis associated with vitamin B12deficiency causes macrocytic anemias. These anemias are characterized by abnormal maturation of erythrocyte precursors in the bone marrow, which results in the presence of megaloblasts and in decreased erythrocyte survival.3,10Pernicious anemia is a macrocytic anemia caused by vitamin B12deficiency that is due to lack of intrinsic factor.5,6Low vitamin B12intake, gastrectomy, diseases of the small intestine, malabsorption, and transcobalamin deficiency can also cause vitamin B12deficiency.3Pregnant women need increased amounts of folate for proper fetal development.11If a woman has a folate deficiency prior to pregnancy, it will be intensified during gestation and may lead to premature birth and neural tube birth defects, such as spina bifida, in the child.11

Nutrition & Vitamins

The risk of forming kidney stones may be continuous rather than dichotomous and begins to increase at urinary calcium excretion >200 mg/day.7-9Urinary calcium reflects in part the relation between GFR and tubular reabsorption.

Nutrition & Vitamins, Liver & Kidney Health

Ceruloplasmin is an α2-globulin containing copper. About 70% or more of total serum copper is associated with ceruloplasmin, 7% with a high MW protein, transcuprein, 19% with albumin, and 2% with amino acids.1Laboratory parameters of Wilson's disease include decreased serum ceruloplasmin, decreased serum copper concentration, increased 24-hour urine copper excretion, increased liver copper concentration, and abnormal liver function studies. Demonstration of failure to incorporate radiolabeled copper into ceruloplasmin is the definitive test for Wilson's disease. Liver and CNS manifestations of Wilson's disease need not both be present. Kayser-Fleischer rings are extremely helpful findings.Excessive therapeutic zinc may lead to block of intestinal absorption of copper and a copper deficiency syndrome characterized by hypochromic microcytic anemia with leukopenia/neutropenia and zero level of ceruloplasmin. A prolonged period of time may be required to eliminate the excess zinc, overcome the block of intestinal copper absorption and obtain increase in serum copper and ceruloplasmin levels.2

Nutrition & Vitamins, General Health & Wellness

Test is used to determine vitamin B6 deficiency or overdosage, for monitoring treatment, and to evaluate wellness and health.

Blood Disorders, Nutrition & Vitamins

Serum measurements are useful in the diagnosis of iron deficiency and hemochromatosis.

Nutrition & Vitamins, General Health & Wellness

Potassium measurements are useful in monitoring electrolyte balance in the diagnosis and treatment of disease conditions characterized by low or high blood potassium levels. Potassium is elevated in adrenal cortical insufficiency, acute renal failure and in some cases of diabetic acidosis. Potassium is decreased in diuretic administration and renal tubular acidosis.

Nutrition & Vitamins, Bone Health

Serum calcium is involved in the regulation of neuromuscular and enzyme activity, bone metabolism and blood coagulation. Calcium blood levels are controlled by a complex interaction of parathyroid hormone, vitamin D, calcitonin and adrenal cortical steroids. Calcium measurements are useful in the diagnosis of parathyroid disease, some bone disorders and chronic renal disease. A low level of calcium may result in tetany.

Nutrition & Vitamins, Fitness & Performance

Chronic oral zinc supplementation interferes with copper absorption and may precipitate copper deficiency. Albumin is the primary zinc binding protein: zinc levels should be interpreted with awareness of serum albumin level.

Nutrition & Vitamins, General Health & Wellness

Magnesium measurements are used in the diagnosis and treatment of hypomagnesemia (abnormally low plasma levels of magnesium) and hypermagnesemia (abnormally high plasma levels of magnesium). Magnesium is decreased in chronic nephritis, acute pancreatitis, and alcoholic cirrhosis. It is increased in acute or chronic renal failure and Addison's Disease.

Nutrition & Vitamins

Transferrin is responsible for 50% to 70% of the iron binding capacity of serum. Since other proteins may bind iron, transferrin is not the same as TIBC. Transferrin is an iron transport protein receiving and binding iron for delivery to receptors at recipient cells. The human transferrin gene, responsible for production of this single chain, 77 kilodalton polypeptide resides on chromosome 3, band q21-25. Transferrin has two iron-binding sites and is largely but not exclusively synthesized by the liver. There are over 20 genetic variants, largely single amino acid substitutions. Transferrin levels rise with iron deficiency and fall in cases of iron overload. Transferrin is normally only about one-third saturated and is responsible for circadian variation in serum iron (peak in AM) due to variable activity of the reticuloendothelial system. Recent studies have indicated that the serum transferrin receptor levels can be used as an index of iron deficiency anemia.

Nutrition & Vitamins, Liver & Kidney Health

Serum albumin measurements are used in the monitoring and treatment of numerous diseases involving primarily the liver and kidney. Its main value lies in the follow-up therapy where improvement in the serum albumin level is the best sign of successful medical treatment. There may also be a loss of albumin in the gastrointestinal tract, in the urine by the damaged kidney or direct loss of albumin through the skin. More than 50% of patients with gluten enteropathy have depressed albumin. The only cause of increased albumin is dehydration; there is no naturally occurring hyperalbuminemia.

Nutrition & Vitamins

This quantitative test, performed with a 24-hour urine specimen, may help screen for hypercalciuria, one of the established risk factors for kidney stone formation [1-3]. This test may also help assess metabolic disorders of calcium metabolism, such as hyperparathyroidism, bone disease, and idiopathic hypercalciuria. In general, 24-hour urine specimens are preferred to random urine specimens when measuring calcium for diagnostic evaluation of hypercalciuria [1].Calcium is essential for bone formation and nerve, muscle, and heart functions. Calcium metabolism is jointly regulated by parathyroid hormone and vitamin D metabolites. Urinary calcium excretion is the major route of calcium elimination and reflects kidney tubular filtration and reabsorption of calcium in addition to dietary intake, intestinal absorption, and bone resorption [2].Urinary calcium levels may be elevated in patients with idiopathic hypercalciuria, chronic kidney disease, hyperparathyroidism, vitamin D intoxication, Paget disease of bone, sarcoidosis, or conditions that infiltrate and destroy bones (eg, multiple myeloma and a variety of metastatic cancers) [2,3]. Urinary calcium levels may be decreased in patients with hypoparathyroidism, vitamin D deficiency rickets, osteomalacia, or familial hypocalciuric hypercalcemia [2,3].Note that use of calcium supplements and loop diuretics may cause increased urinary calcium levels; thiazide diuretics may cause decreased urinary calcium levels [3].This test is also available with creatinine (Calcium, 24-Hour Urine with Creatinine). Because daily urine excretion of creatinine generally shows minimal fluctuation, creatinine excretion is useful in determining whether 24-hour urine specimens for calcium have been completely and accurately collected [2].The results of this test should be interpreted in the context of pertinent clinical and family history and physical examination findings.References1. Williams JC Jr, et al.Urolithiasis. 2021;49(1):1-16.2. Rifai N, et al. eds.Tietz Textbook of Laboratory Medicine. 7th ed. Elservier Inc; 20223. MedlinePlus [Internet]. Calcium-urine. Accessed September 1, 2022.https://medlineplus.gov/ency/article/003603.htm

Blood Disorders, Nutrition & Vitamins

Useful in the diagnosis of hypochromic, microcytic anemias. Decreased in iron deficiency anemia and increased in iron overload.

Blood Disorders, Nutrition & Vitamins

Serum iron quantification is useful in confirming the diagnosis of iron-deficiency anemia or hemochromatosis. The measurement of total iron binding in the same specimen may facilitate the clinician's ability to distinguish between low serum iron levels caused by iron deficiency from those related to inflammatory neoplastic disorders. The assay for iron measures the amount of iron which is bound to transferrin. The total iron binding capacity (TIBC) measures the amount of iron that would appear in blood if all the transferrin were saturated with iron. It is an indirect measurement of transferrin concentrations but expressed as an iron measurement. To obtain the percent saturation, the serum iron is divided by the TIBC which gives the actual amount of saturated transferrin. The percent saturation is low in iron deficiency and high in iron storage diseases.

Liver & Kidney Health, Nutrition & Vitamins

Serum uric acid measurements are useful in the diagnosis and treatment of numerous renal and metabolic disorders, including renal failure, gout, leukemia, psoriasis, starvation or other wasting conditions, and in patients receiving cytotoxic drugs.

Nutrition & Vitamins

This panel comprises a group of 4 tests that provide information on an individual's electrolytes, acid-base, and water balance. The panel is usually ordered during hospital and emergency room admission to help diagnose a range of conditions as well as monitor certain conditions or treatments that affect electrolyte balance [1].Symptoms and signs of electrolyte, acid-base, and water imbalance may include dehydration, edema, vomiting, weakness, confusion, and cardiac arrhythmias. These imbalances may be associated with kidney diseases, respiratory distress, and metabolic disorders [1]. The results of the panel components are usually evaluated jointly for patterns. The section below outlines the roles of the analytes assessed with this panel [1].Sodium: An electrolyte that plays a central role in maintaining the normal distribution of water and appropriate pressure to assure that substances do not leak from cells and organs. Sodium measurements are useful in the diagnosis and treatment of diseases involving electrolyte imbalance.Potassium: An electrolyte that is essential for proper muscle and nerve function and helps keep the balance of fluids. Potassium measurements are useful in assessing electrolyte balance in the diagnosis and treatment of conditions characterized by low or high blood potassium levels.Chloride: An electrolyte that helps maintain volume, acidity, and electrical neutrality of the body fluids. Chloride measurements are useful in the diagnosis and treatment of electrolyte and metabolic disorders, such as cystic fibrosis and diabetic acidosis.Carbon dioxide (bicarbonate): A type of blood gas used to evaluate the total carbonate buffering system and acid-base balance. Carbon dioxide is generally evaluated with other common electrolytes; the measurements are useful in the diagnosis and treatment of numerous potentially serious disorders associated with changes in body acid-base balance.References1. Rao LV, et al. Laboratory tests. In: Rao LV, eds.Wallach's Interpretation of Diagnostic Tests. Pathways to Arriving at a Clinical Diagnosis.11th ed. Wolters Kluwer; 2020.

Nutrition & Vitamins, Blood Disorders

Folic acid deficiency is common in pregnant women, alcoholics, in patients whose diets do not include raw fruits and vegetables, and in people with structural damage to the small intestine. The most reliable and direct method of diagnosing folate deficiency is the determination of folate levels in both erythrocytes and serum. Low folic acid levels, however, can also be the result of a primary vitamin B12deficiency that decreases the ability of cells to take up folic acid.

Nutrition & Vitamins

PTH is an 84-amino-acid peptide hormone which is responsible for the regulation of serum calcium levels within a narrow range. PTH is secreted in response to decrease in serum calcium levels by increasing the renal reabsorption of calcium and lowering reabsorption of phosphorus. The measurement of PTH is a very useful tool in the differential diagnosis and management of hypercalcemia. PTH assays can be of help in the diagnosis of tumors and hyperplasia of the parathyroid gland, as well as in localizing hyperfunctioning parathyroid tissue by assay of samples obtained via venous catheterization. The native or intact (1-84) PTH has a short half-life, measured in minutes, whereas the carboxy and midmolecule fragments, which are biologically inactive, have half-lives 10- to 20-fold higher. The high concentrations of biologically inactive fragments have interfered with use of C-terminal or midmolecule assays for evaluation of parathyroid function in patients with impaired renal function. Intact PTH assays provide a more accurate assessment of parathyroid patients including those with various renal diseases.

Nutrition & Vitamins, Blood Disorders

Offered as part of multiple lab tests

Nutrition & Vitamins

Prealbumin is functional in transporting T4and T3. It is a negative acute phase reactant and has a molecular mass of 54,000.

Nutrition & Vitamins, Liver & Kidney Health

Decreased levels of ceruloplasmin are found in Wilson's Disease, fulminant liver failure, intestinal malabsorption, renal failure resulting in proteinuria, chronic active hepatitis and malnutrition. Elevated levels are found in primary biliary cirrhosis, pregnancy (first trimester), oral contraceptive use and in acute inflammatory conditions since ceruloplasmin is an acute phase reactant.

Nutrition & Vitamins

Calcium in serum exists ionized, bound to organic anions such as phosphate and citrate, and bound to proteins (mainly albumin). Of these, ionized calcium is the physiologically important form. Measurement of serum ionized calcium provides insight into the effect of total protein and albumin on serum calcium levels. A patient can have high total calcium, with normal ionized calcium and increased total protein and/or albumin, as in dehydration or in myeloma. Women have greater circadian variation of ionized calcium and intact PTH than men.1There is an inverse relationship between ionized calcium and phosphate concentration.2

Nutrition & Vitamins, General Health & Wellness

Hypokalemia (low potassium)has been found in >90% of hypertensive patients with primary aldosteronism (Conn syndrome). This uncommon entity is a curable cause of hypertension. Low potassium occurs with endogenous or exogenous increase in other corticosteroids, including that in Cushing syndrome as well as with dietary or parenteral deprivation of potassium (eg, parenteral therapy without adequate potassium replacement). Hypokalemia occurs with vomiting, diarrhea, fistulas, laxatives, diuretics, burns, excessive perspiration, Bartter syndrome, some cases of alcoholism and folic acid deficiency, in alkalosis and in renal tubular acidosis as well as in other entities.Low potassium is much more significant with a low pH than with a high pH. When pH increases by 0.1, potassium decreases approximately 0.6 mmol/L. With low pH, as in ketoacidosis, as therapeutic adjustment towards normal is made, plasma/serum K+levels will decrease. Phosphorus levels tend to follow potassium levels downwards during therapy of diabetic ketoacidosis; both are largely intracellular. With insulin therapy (and increased utilization of carbohydrate), potassium moves into cells and serum/plasma level falls. Hyperalimentation may have a similar effect. Hypokalemia has been reported in slightly over one-half of a series of 32 patients with acute myelogenous leukemia,1but thrombocytosis can increase serum potassium levels, vide supra.Thiazide/chlorthalidone therapy may cause hyperuricemia and hypercalcemia as well as hypokalemia.The watery diarrhea-hypokalemia-achlorhydria (WDHA) syndrome most often is related to vasoactive intestinal polypeptide (VIP).Hyperkalemia (high potassium)reflects generally inadequate renal excretion, mobilization of potassium from the tissues, or excessive intake or administration. Hyperkalemia occurs with hemolysis, trauma, with administration of potassium salts of some drugs, Addison disease, acidosis, insulin lack, with increased osmolality (eg, glucose, mannitol), and in other entities as well as with renal diseases. Increased potassium can occur with potassium sparing diuretics, nonsteroidal anti-inflammatory drugs, especially in the presence of renal disease. Systemic heparin therapy can suppress aldosterone release and increase potassium, especially in the presence of other factors.A discussion of the relation between lactic acidosis and ketoacidosis and elevated serum potassium levels is provided in a paper by Fulop.2Drug effects are summarized.3

Nutrition & Vitamins, Blood Disorders

Folic acid deficiency is common in pregnant women, alcoholics, patients with diets that do not include raw fruits and vegetables, and people with structural damage to the small intestine. The most reliable and direct method of diagnosing folate deficiency is the determination of folate levels in both erythrocytes and serum. Low folic acid levels, however, can also be the result of a primary Vitamin B12 deficiency that decreases the ability of cells to take up folic acid.B12 is decreased in pernicious anemia, total or partial gastrectomy, malabsorption and certain congenital biochemical disorders.

Nutrition & Vitamins

False elevations of potassium may be due to hemolysis or rupture of platelets during coagulation process. The use of plasma potassium levels should be limited to those patients with spuriously elevated or depressed potassium levels due to blood samples left at room temperature, in patients with chronic lymphocytic leukemia with very high WBC counts (false decline), and those with thrombocytosis (increased platelets) with counts in excess of one million (false elevation).

Nutrition & Vitamins, Bone Health

Serum phosphorus (Phosphate) levels alone are of limited diagnostic value and should be correlated with serum calcium levels. An increased phosphorus with decreased calcium suggests either hypoparathyroidism or renal disease. A decreased phosphorus and an increased calcium suggests hyperparathyroidism or sarcoidosis. When both calcium and phosphorus are decreased diagnostic considerations include malabsorption, vitamin D deficiency and renal tubular acidosis. Increased phosphorus and normal or increased calcium suggests Milk-alkali syndrome or hypervitaminosis D.

Nutrition & Vitamins, Blood Disorders

B12 is decreased in pernicious anemia, total or partial gastrectomy, malabsorption and certain congenital and biochemical disorders.

Nutrition & Vitamins, Liver & Kidney Health

The excretion of sodium varies with dietary intake. There is a diurnal variation of sodium excretion with excretion being greater during daytime than during the night. Decreased levels are seen in congestive heart failure, excessive sweating, diarrhea, pyloric obstruction, malabsorption and primary aldosteronism. Increased levels may be due to increased salt intake, failure of the adrenal glands, diabetic acidosis, salt losing renal disease and water deficient dehydration.

Digestive Health, Nutrition & Vitamins

Offered as part of multiple lab tests

Nutrition & Vitamins, Fitness & Performance

Zinc is an essential element involved in a myriad of enzyme systems including wound healing, immune function, and fetal development. Zinc measurements are used to detect and monitor industrial, dietary, and accidental exposure to zinc. Also, zinc measurements may be used to evaluate health and monitor response to treatment.

Nutrition & Vitamins

The majority of 25-OH vitamin D (25-D) in the circulation is derived from the conversion of 7-dehydrocholesterol in the skin that is irradiated with ultraviolet radiation in the UVB range (wavelength 290 nm to 315 nm).1-5The extent of vitamin D formation is not tightly controlled and depends primarily on the duration and intensity of the UV irradiation. Levels produced typically reach a plateau within 30 minutes of exposure. Unfortunately, use of a sunscreen with SPF as low as 15 reduces the rate of vitamin D production by 99.9%. Overproduction of vitamin D in the skin is prevented by the photosensitive conversion of vitamin D to tachysterol or lumisterol. Vitamin D is not very water-soluble, so it must be delivered to and carried in the blood as a complex with vitamin D-binding protein. Once in the circulation, vitamin D is metabolized to 25-hydroxy vitamin D (25-D) by the liver. The 25-D form of the hormone is the principle circulating reservoir in plasma and is generally the best indicator of overall vitamin D status. 25-D is further metabolized by the kidney to produce the biologically active form of vitamin D, 1,25-dihydroxy vitamin D (1,25-D). Renal production of 1,25-D is tightly controlled by parathyroid hormone and is important in the regulation of serum calcium homeostasis.The hormonally active form of vitamin D,1,25-D plays an integral role in calcium homeostasis and the maintenance of healthy bone.1-41,25-D stimulates the absorption of calcium at the level of the intestine and may also serve to increase calcium and phosphate resorption at the kidney level. Vitamin D deficiency leads to the mobilization of calcium from bone. Individuals with more severe vitamin D deficiency can develop osteomalacia and/or osteoporosis. Osteomalacia in children, also referred to as rickets, results in well-described skeletal malformations, since children's bones are actively growing. Recent clinical and epidemiological studies suggest that vitamin D deficiency may play a role in several conditions unrelated to bone, including prostate cancer, breast cancer, colon cancer, heart disease, hypertension, multiple sclerosis, and type 1 diabetes.A number of studies have shown that vitamin D deficiency is very common, especially in certain high-risk populations.1,2This situation has occurred, in part, because the foods in the typical American diet are very low in vitamin D. Fatty fish, such as mackerel and salmon, and fish liver oils are some of the few natural dietary sources of vitamin D. Most people do not eat enough of these foods to maintain adequate vitamin D levels. In the United States, vitamin D is added to milk in order to prevent the occurrence of rickets in the pediatric population. Unfortunately, too many children do not drink enough milk to raise their vitamin D levels to the optimum range. Also, recent studies have shown that the level of vitamin D in fortified milk is frequently much lower than that recommended by the FDA. Human milk contains very little vitamin D because many mothers are deficient, so children of mothers who choose to breast-feed are at risk of developing rickets if they are not given supplemental vitamin D. The American Academy of Pediatrics recommends that infants who are exclusively breast-feeding should be given a supplement of vitamin D.Several factors are associated with an increased risk of developing vitamin D deficiency. At risk populations include:1-5• Individuals with low dietary vitamin D levels. Infants fed only mother's milk and children who do not drink fortified milk are at risk.• Individuals with malabsorption syndromes. Patients with pancreatic enzyme deficiency, Crohn's disease, cystic fibrosis, celiac disease, and surgical resection of stomach or intestines are at risk.• Individuals with severe liver disease. Hepatic disease can reduce the conversion of vitamin D to 25-D and can lead to malabsorption of vitamin D.• Individuals with kidney disease. Nephrotic syndrome can increase the urinary loss of vitamin D.• Individuals taking certain drugs. Several medications, including phenytoin, phenobarbital, and rifampin accelerate the breakdown of vitamin D by the liver.• Individuals who live at higher latitudes. Individuals who live in northern climates are at increased risk of deficiency, especially in winter months due to diminished exposure to UVB radiation.• Individuals who spend little time outside. Individuals who are homebound or simply choose to remain inside are at increased risk.• Older adults. The skin becomes less efficient at producing vitamin D as one ages because of diminished levels of vitamin D precursors in the skin.• Individuals with decreased sun exposure for cultural reasons. Women in some societies are required to cover themselves with heavy clothing, reducing exposure to the sun's rays.• Races with high melanin levels. Increased skin pigmentation can reduce the efficiency of vitamin D conversion in the skin as much as 50-fold. Individuals with dark complexions living at higher latitudes are at increased risk.Serum concentrations of 25-D are known to vary with age, sex, race, season, and geographic location. This has led to the establishment of seasonal expected ranges for geographic locations and local populations. This approach provides a “reference interval” but does not adequately determine health status with regard to vitamin D levels if a significant portion of the reference population is, in fact, deficient. A more useful parameter in clinical practice would be a nutritional threshold below which an individual could be characterized as vitamin D-deficient. Vitamin D deficiency has been defined by the Institute of Medicine and an Endocrine Society practice guideline as a level of serum 25-hydroxy vitamin D <20 ng/mL.1,3The Endocrine Society went on to define vitamin D insufficiency as levels between 21 and 29 ng/mL.3Vitamin D plays an integral role in calcium homeostasis and the maintenance of healthy bone. Vitamin D stimulates the absorption of calcium at the level of the intestine and may also serve to increase calcium and phosphate resorption at the kidney level. Deficiency of vitamin D leads to the mobilization of calcium from bone, which can lead to osteoporosis, osteomalacia, and rickets.1-3Numerous recent studies have shown a strong association between diminished vitamin D levels and risk for falls6and for both vertebral and nonvertebral fractures.7The World Health Organization's International Agency for Research on Cancer (IARC) has concluded that there is a strong link between an individual's vitamin D levels and the risk of developing colorectal cancer.5Studies have also revealed that low vitamin D levels are associated with an increased incidence of other malignancies, including breast cancer.8Many tissues and cells in the body have vitamin D receptors.1-3It has been estimated that the expression of as much as one third of the human genome is influenced by 1,25-(OH)2 vitamin D. Many studies have demonstrated an association of vitamin D deficiency with increased risk for:• Autoimmune diseases, including both type 1 and type 2 diabetes, rheumatoid arthritis, Crohn's disease, and multiple sclerosis.• Infectious diseases and asthma• Cardiovascular disease and hypertensionThere are, however, few randomized, controlled trials with a dosing range adequate to provide strong evidence of the benefit of vitamin D in reducing the risk of these chronic diseases.3

Nutrition & Vitamins

Patients with xanthomas should be worked up with lipid panels, but not those with xanthelasmas or xanthofibromas in the sense of dermatofibromas. Those whose fasting serum is lipemic should have a lipid panel, but the serum of a subject with high cholesterol (but normal triglyceride) is not milky in appearance. The patient with high cholesterol (>240 mg/dL) should have a lipid panel. Patients with cholesterol levels between 200−240 mg/dL plus two other coronary heart disease risk factors should also have a lipid panel.1In addition to application in screening programs for evaluation of risk factors for coronary arterial disease, lipid profiling may lead to detection of some cases of hypothyroidism.Primary hyperlipoproteinemiaincludes hypercholesterolemia, a direct risk factor for coronary heart disease.Secondary hyperlipoproteinemiaincludes nephrosis, renal failure, obesity, diabetes mellitus, alcoholism, primary biliary cirrhosis, and other types of cholestasis. Decreased lipids are found with some cases of malabsorption, malnutrition, and advanced liver disease. In abetalipoproteinemia, cholesterol is <70 mg/dL.

Nutrition & Vitamins

In cases of hyponatremia, urine sodium <10 mmol/L may indicate extrarenal depletion: dehydration (gastrointestinal or sweat loss), congestive heart failure, liver disease or nephrotic syndromes.Urine sodium >10 mmol/L may indicate diuretics, emesis, intrinsic renal diseases, Addison disease, hypothyroidism, or syndrome of inappropriate antidiuretic hormone (SIADH).2In hypothyroidism and in SIADH, Na+and Cl-may be >40 mmol/L.3(Depending on intake, such results also can be found in normal individuals.) In SIADH, urinary sodium is usually >20 mmol/L. Inappropriate secretion of antidiuretic hormone (SIADH) was found in 7% of 250 patients with small cell lung cancer.4Such patients have hyponatremia, often severe, with hypo-osmolar serum, high urinary sodium excretion with urine osmolality greater than that of serum. Acute and subacute diseases of the CNS, TB and other chronic pulmonary diseases may also cause SIADH. SIADH may also be caused by acute intermittent porphyria, LE, occasional malignant neoplasms other than small cell carcinoma of lung, and a number of drugs.5The classification as presented here is overly abbreviated for clinical application. Pitfalls exist (eg, increase of Na+necessary to balance excretion of penicillin).3Urine Na+>40 mmol/L in oliguria suggests acute tubular necrosis.3,6(However, spot urine sodiums without other data have been criticized for their applicability to this diagnosis.)Low Na+excretion may be found with early obstructive uropathy and with the oliguria of acute glomerulonephritis3and in some patients with x-ray contrast acute renal failure.Silver et al recommend measurement of urinary Na+excretion in patients with nephrolithiasis and hypercalciuria.7It is important to know the urinary sodium level in patients with unexplained hyperchloremic metabolic acidosis when the diagnosis of distal renal tubular acidosis is being considered.8

Nutrition & Vitamins

Urinary potassium may be elevated with dietary (food and/or medicinal) increase, hyperaldosteronism, renal tubular acidosis, onset of alkalosis, and with other disorders. Time relationships are important in interpretation. Potassium will decrease in Addison's disease and in renal disease with decreased urine flow (nephrosclerosis, pyelonephritis, glomerulonephritis).

Nutrition & Vitamins

Urinary excretion of potassium is increased in primary aldosteronism. It is often increased in dehydration and in salicylate toxicity. Decreased levels are seen in malabsorption.

Nutrition & Vitamins

Urinary excretion of potassium is increased in primary aldosteronism. It is often increased in dehydration and in salicylate toxicity. Decreased levels are seen in malabsorption.

Blood Disorders, Nutrition & Vitamins

This serum iron study panel may help diagnose iron deficiency or overload. Because ferritin level can be affected by clinical conditions other than iron disorders, the measurement of transferrin saturation-calculated from serum iron level and total iron binding capacity (TIBC)-in the same serum specimen may facilitate the diagnosis of iron deficiency or overload [1-3].Serum ferritin level generally reflects body iron storage and can be used in the diagnosis of iron deficiency and overload. Transferrin saturation is the percentage of iron bound to transferrin. In patients with anemia, ferritin levels are most frequently used to determine whether iron deficiency is the cause [1]. However, as an acute phase protein, ferritin levels can be increased independently of iron status in inflammatory conditions, kidney disease, liver disease, and malignancy. In these clinical scenarios, the combination of ferritin level with other tests, such as transferrin saturation, may aid in the evaluation of iron deficiency [1,3].In patients with suspected hemochromatosis, transferrin saturation and serum ferritin may be included in the initial evaluation of iron overload [2]. The combination of a transferrin saturation under 45% and a normal serum ferritin level may help exclude iron overload. A transferrin saturation equal or over 45% alone or with an elevated ferritin level may suggest further testing. Serum ferritin level is also a predictor of advanced fibrosis [2].Note that reference intervals of serum iron, TIBC, transferrin saturation, and ferritin depend upon age and sex.The results of this test should be interpreted in the context of pertinent clinical and family history and physical examination findings.References1. Ko CW, et al.Gastroenterology. 2020;159(3):1085-1094.2. Kowdley KV, et al.Am J Gastroenterol. 2019;114(8):1202-1218.3. Lopez A, et al.Lancet. 2016;387(10021):907-916.

Nutrition & Vitamins, Liver & Kidney Health

The excretion of sodium varies with dietary intake. There is a diurnal variation of sodium excretion with excretion being greater during daytime than during the night. Decreased levels are seen in congestive heart failure, excessive sweating, diarrhea, pyloric obstruction, malabsorption and primary aldosteronism. Increased levels may be due to increased salt intake, failure of the adrenal glands, diabetic acidosis, salt losing renal disease and water deficient dehydration.

Heart Health & Cardiovascular, Nutrition & Vitamins

Severe homocysteinemia is typically caused by a rare inborn error of metabolism.1,2The most common defect that can produce levels >100 μmol/L is homozygous cystathionine-β-synthase (CS) deficiency, which occurs with an incidence of 1 per 300,000 live births. About 1% of the population has heterozygous CS deficiency, a condition that typically results in moderate to intermediate hyperhomocysteinemia. Individuals with CS deficiency are at increased risk for occlusive vascular disease.1,2Individuals with a thermolabile variant of the enzyme methylene-tetrahydrofolate reductase can have high normal to moderately elevated levels of homocysteine.1,2Homocysteine can be considered to be an independent risk factor for the development of cardiovascular disease.1-3Patients with cardiovascular disease, including heart disease, stroke, peripheral vascular disease, and thromboembolic disease generally have higher homocysteine levels than matched controls. The results of a large number of epidemiological studies have been analyzed through a meta-analysis.1The increased risk, or odds ratio (OR), for coronary artery disease in patients with increased homocysteine levels was estimated to be 1.7. The OR for stroke was estimated to be 2.5 and the OR for peripheral vascular disease was estimated to be 6.8. Several conditions, other than specific genetic defects or cardiovascular disease, have been associated with hyperhomocysteinemia.1These include vitamin deficiency, advanced age, hypothyroidism, impaired kidney function, and systemic lupus erythematosus. Medications including nicotinic acid, theophylline, methotrexate, and L-dopa have been reported to cause elevated homocysteine levels.

Nutrition & Vitamins

Vitamin A serum levels do not correlate well with liver stores. Carotenemia may be confused with jaundice. It is also reported high with some cases of diabetes mellitus, myxedema, chronic nephritis, nephrotic syndrome,1,2liver disease, hypothyroidism, type I, IIA, and IIB hyperlipoproteinemia, and in a group of amenorrheic hypogonadotropic women.1An inverse relationship between serum β-carotene and the risk of bronchogenic squamous cell carcinoma is reported.3The highest carotene levels are found in the serum of faddists ingesting large amounts of vegetables.4Oral leukoplakia responds well to β-carotene therapy.5Low β-carotene levels are associated with oral contraceptives and smoking.6

Nutrition & Vitamins, General Health & Wellness

Vitamin A is the name given to a group of biologically active, fat-soluble molecules that includes retinol, retinal and retinoic acid.1,2These retinoid compounds are derived from the plant precursor molecule, β-carotene. β-carotene (also referred to as provitamin A) has a structure that consists of two molecules of retinal linked at their aldehyde ends.1β-carotene is converted to vitamin A by intestinal absorptive cells and hepatocytes.1,2Vitamin A is stored in the liver and transported to extrahepatic tissues bound to retinol binding protein and albumin.1Both retinol and β-carotene levels are measured in plasma for assessing vitamin A inadequacy and/or toxicity.Vitamin A exists in humans in several forms and is tightly controlled. Naturally occurring forms of vitamin A include retinol, retinol esters, retinal and retinoic acid. The alcohol form, retinol, predominates in the circulation, but it is too toxic for storage. Instead, the liver stores as retinyl esters - principally palmitate. The active form of vitamin A in the visual cycle is the aldehyde form, retinal. Retinoic acid is the form in tissues responsible for the biological actions of vitamin A in cellular division and differentiation.11The most important measurand for the estimation of vitamin A status is circulating vitamin A as retinol. Serum retinol levels do not accurately reflect liver retinyl ester levels. Despite this limitation, serum retinol is still useful because the levels will diminish once the supply from the liver is diminished. The serum retinol level at which vitamin A deficiency occurs will coincide with the manifestation of night blindness, due to the interruption of the visual cycle by lack of retinal. Other more serious symptoms will occur later when retinoic acid is depleted by even less available hepatic retinyl esters.12The body must acquire vitamin A from the diet in order to sustain a number of essential physiological processes.3These include vision, organogenesis, tissue differentiation, immune function, reproduction, embryonic development and maintenance of healthy skin and barrier functions.3-7More than five hundred genes are thought to be regulated by vitamin A.3Vitamin A deficiency only manifests when liver stores are depleted by prolonged reduction of dietary intake.1,10In healthy individuals, serum retinol concentrations are homeostatically controlled and do not begin to decline until liver reserves of vitamin A are dangerously low.2,4,10The initial symptom of vitamin A deficiency is an inability to adapt vision to darkness (ie, night blindness).1Vitamin A is an essential component of rhodopsin, a protein that absorbs light in the retinal receptors.2Vitamin A also supports the normal differentiation and functioning of the conjunctival membranes and cornea.2Protracted vitamin A deficiency causes degenerative changes in the retina due to progressive keratinization of the cornea, a condition referred to as xerophthalmia.2In developing countries, vitamin A deficiency is the most common cause of preventable blindness.Additional symptoms of vitamin A deficiency include follicular hyperkeratosis, increased susceptibility to infection and an anemia similar to iron deficient anemia.1β-carotene is an important, but insufficient, source of vitamin A among poor populations due to the inefficiency of the conversion to retinol.5Vitamin A deficiency in poor countries is also a significant cause of infection and death, particularly from diarrhea and measles.6Excessive levels of vitamin A can lead to toxicity. Vitamin A intoxication is a concern in normal adults who ingest more than 15 mg per day and children who ingest more than 6 mg per day of vitamin A for a period of several months. The symptoms of acute vitamin A toxicity include dizziness, nausea, vomiting, headaches, blurred vision, vertigo, reduced muscle coordination, skin exfoliation.13,14More chronic vitamin A toxicity symptoms include weight loss, fatigue cheilosis, glossitis, alopecia, bone demineralization, hypercalcemia, lymph node enlargement, hyperlipidemia and amenorrhea. Excess accumulation of vitamin A in the liver can also lead to hepatosplenomegaly, liver fibrosis with portal hypertension.1,13Congenital malformations, including craniofacial abnormalities and valvular heart disease as well as spontaneous abortions have been reported in children born to pregnant women taking vitamin A in excess. A number of studies have reported an increased risk of lung cancer among high-risk individuals (smokers and asbestos workers) who were given high doses of β-carotene alone or in combination with other antioxidants.5Toxicity generally results from excessive ingestion of vitamin A supplements but regular intake of large amounts of liver, although usually not a problem in vitamin A-deficient areas, may also result in toxicity due to its high content of vitamin A.15The World Health Organization recommendations supplementation when vitamin A levels fall below 20.0 ug/dL.16Severe deficiency is indicated at levels <10.0 ug/dL.2,9,10

Blood Disorders, Nutrition & Vitamins

Use in evaluating erythropoietic activity.

Blood Disorders, Nutrition & Vitamins

Transferrin is a direct measure of the iron binding capacity. Transferrin is thus useful in assessing iron balance. Iron deficiency and overload are often evaluated with complementary laboratory tests.

Nutrition & Vitamins, Heavy Metals & Toxins

The demand for sensitive noninvasive tests for Wilson's disease, especially for children in families where the disease is known to occur, has stimulated search for newer indices of copper metabolism. Urine copper after penicillamine load has recently been proposed.5

Nutrition & Vitamins

Copper is an essential element that is a cofactor of many enzymes. Copper metabolism is disturbed in Wilson's disease, Menkes disease, primary biliary cirrhosis, and Indian childhood cirrhosis. Copper concentrations increase in acute phase reactions and during the third trimester of pregnancy. Copper concentrations are decreased with nephrosis, malabsorption, and malnutrition. Copper concentrations are also useful to monitor patients, especially preterm newborns, on nutritional supplementation. Results of copper are often interpreted together with ceruloplasmin.

Nutrition & Vitamins

The term vitamin E refers to a class of plant-derived, lipid-soluble compounds which possess a substituted chromanol ring attached to a long phytyl side chain.1-3,12,13The ring structure is necessary to confer vitamin E activity. The human diet includes eight vitamin E compounds: the α-, β-, γ-, and δ-tocopherals and the α-, β-, γ-, and δ-tocotrienols.1-3,13Mammals do not interconvert the tocopherol(TC) isoforms.13γ-TC is found in corn and soybean oil as well as walnuts, pecans, pistachios, and sesame seeds.20The main sources of β-TC and δ-TC are corn, corn oil, and rapeseed oil. Other good sources of δ-TC are tomato seeds, rice germ, and soybean oil.14α-TC is found predominantly in peanuts, almonds, and sunflower seeds.α-TC is the only form of vitamin E that is actively retained by the body.1The TCs are extremely hydrophobic molecules.3Consequently, the delivery of α-TC into target tissues and cells requires the presence of a specific enzyme, α-TC transfer protein (α-TTP).3-5α-TTP also facilitates the intracellular trafficking of α-TC from lysosomes to the plasma membrane and from hepatocytes to circulating lipoproteins.4,13The critical role of this protein and its ligand are revealed by the debilitating pathologies that characterize individuals with mutations in the α-TTP gene.3,4Heritable mutations in this protein lead to severe vitamin E deficiency characterized by progressive neurodegeneration, ataxia and eventually death if vitamin E is not provided in large quantities to overcome the lack of α-TTP.2Due to lack of specific transfer mechanisms, other tocopherols and tocotrienols are not efficiently retained by the liver, and are instead metabolized, and predominantly eliminated.21As a result, tissue levels of α-TCs are 10-fold higher than the levels of other TCs.4,13α-TC acts as a lipid-soluble peroxyl radical scavenger that disrupts the chain reaction by which lipid peroxidation propagates.3,6During lipid oxidation, oxidized tocopheroxyl radicals are produced that can be recycled back to the active, reduced form through reduction by vitamin C.13This process prevents oxidative damage to long-chain polyunsaturated fatty acids in cell membranes during times of oxidative stress.1,2,3,6Consequently, vitamin E adequacy is critical for numerous physiologic functions that rely on bilayer integrity such as cell permeability and adhesion.6α-TC is also thought to play a role in controlling the expression of several genes.7Symptomatic dietary vitamin E deficiency is rare.3The main manifestation of deficiency is peripheral neuropathy associated with the degeneration of the large-caliber axons of sensory neurons.10Clinical features include dysarthria, clumsiness of the hands, loss of proprioception, areflexia, dysdiadochokinesia, decreased visual acuity, and positive Babinski sign. Primary deficiency is seen in cases of the autosomal recessive disorder ataxia due to heritable mutations in α-TTP.3Primary deficiency is associated by very low plasma vitamin E levels.3Secondary deficiency occurs in disorders of lipid absorption or lipoprotein metabolism and transport.3Compromised intestinal fat absorption diseases including cholestatic liver disease, short bowl syndrome, Crohn's disease, and abetalipoproteinemia can cause secondary vitamin E deficiency.3Cystic fibrosis associated fat malabsorption can also cause deficiency in fat-soluble vitamins, including vitamin E. Diseases caused by molecular defects that affect lipid transport and trafficking, including Niemann-Pick disease-type C and Tangier disease are also associated with vitamin E deficiency. Vitamin E deficiency is also seen in some hematological disorders including, beta-thalassemia major, sickle-cell anemia, and glucose-6-phosphate dehydrogenase deficiency.1A number of animal studies, observational human studies, and clinical trials have investigated the possibility that vitamin E may have a cardioprotective effect.8α-TC has been shown to increase oxidative resistance in vitro and to reduce atherosclerotic plaque formation in mouse models. In addition, α-TC inhibits oxidation of low- density lipoprotein cholesterol and modulates expression of proteins involved in the uptake, transport, and degradation of atherogenic lipids.14Consumption of foods rich in α-TC has been associated with decreased risk of coronary heart disease in middle-aged to older men and women. While some reports have been encouraging, the majority of clinical studies have not demonstrated a benefit of vitamin E supplementation in the primary and secondary prevention of cardiovascular disease.8,14Animal studies have reported preventive effects of vitamin E on Alzheimer's disease neuropathology.26A recent study found that α-TC was effective in slowing the functional decline of mild to moderate Alzheimer disease and was also effective in reducing caregiver time in assisting patients.15However, the therapeutic effect seen was modest and related to disease symptoms and not to the reversal of the disease process.16Vitamin E isoforms may also have a role in the production and clearance of amyloid beta.23Until recently, most research on vitamin E has focused on α-TC, because it is the predominant form of vitamin E in tissues and low intake of α-TC is associated with clinical manifestations including peripheral neuropathy and ataxia.14However, there is accumulating evidence for a role for another member of the vitamin E family, γ-TC in health and disease.14,20γ-TC is the major form of vitamin E in the corn and soybean oils that are a major staple of the American diet.14γ-TC is low in other oils such as sunflower and olive oil that are more prevalent in European diets.13,17The average serum concentrations of α-TC are similar among these populations while serum γ-TC levels in United States are 2- to 6-fold higher than levels in Europeans.13,18It has been suggested that the conflicting outcomes of a number of vitamin E studies performed in different countries may, in part, reflect differences in the serum levels of γ-TC in foods and supplements administered.14,18Reactive oxygen species (ROS) are produced as byproducts of the aerobic cellular metabolism and lipid oxidation.14α- and γ-TC have similar capacity to scavenge these ROS.13,19,20This process produces oxidized TC radicals that are recycled back to their active, reduced forms via reduction by vitamin C.13ROS accumulation beyond the body's ability to scavenge them results in "oxidative stress," which has been implicated in the pathophysiology of numerous diseases.14,19,22Unlike α-TC, γ-TC also reacts with reactive nitrogen species (RNS) that are produced by neutrophilic inflammation.13,18,20It has been suggested that the γ-TC's ability to scavenge RNS may reduce inflammation.18,19Recent studies reveal disparate effects from supplementation with α- γ- and TC in clinical studies of asthma and atherosclerosis.13,17,18,20It has been suggested that excess α-TC taken in supplements causes a reduction of γ-TC concentration in plasma due to more rapid metabolism of γ-TC.24Reports indicate that allergic inflammation is inhibited by supplementation with α-TC but elevated by supplementation with γ-TC.13Studies suggest that γ-TC elevates inflammation in experimental asthma and ablates the anti-inflammatory benefit of α-TC treatment.17A recent clinical study found that α-TC supplementation produced improved spirometric parameters while γ-tocopherol produced a negative effect on spirometric parameters.18Another recent study revealed a positive association between dietary vitamin E intake and lung function, and evidence of an inverse relationship between serum levels of γ-tocopherol and lung function.25

Nutrition & Vitamins

Magnesium is an essential trace element. Deficiency leads to irritability, neuromuscular abnormalities, cardiac and renal damage. Its salts are used as antacids and cathartics. Excessive amount may cause CNS depression, loss of muscle tone, respiratory and cardiac arrest.

Nutrition & Vitamins

Deficiency of vitamin E may cause extensive neuropathy in young children and, in addition, is suspect as a possible cause of motor and sensory neuropathy in older children and in adults. One likely cause of vitamin E deficiency is intestinal malabsorption, resulting from bowel disease, pancreatic disease, or chronic cholestasis. Other causes of malabsorption of vitamin E include celiac disease, cystic fibrosis, and intestinal lymphangiectasia.

Nutrition & Vitamins

Offered as part of multiple lab tests

Nutrition & Vitamins, General Health & Wellness

Vitamin C, also referred to as L-ascorbic acid, is a water-soluble vitamin that is naturally present in some foods, fortified in others, and available as a dietary supplement alone or in multivitamins.1,2Humans, unlike most animals, cannot synthesize vitamin C de novo and must obtain it as an essential dietary component.1,3Vitamin C a is required cofactor for the biosynthesis of a number of critical compounds.2,8It is required for the function of several enzymes involved in the production of collagen, an essential component of connective tissue. These enzymes are required for the molecular cross-linking that gives collagen its elasticity. Vitamin C deficiency renders the polypeptide unstable and unable to self-assemble into rigid triple helices. Impaired collagen production can result in poor wound healing and a weakening of collagenous structures leading to tooth loss, joint pains and bone and connective tissue pathology and blood vessel fragility. Vitamin C also serves as a cofactor in the biosynthesis of carnitine, an essential compound for the transport of activated long chain fatty acids into the mitochondria. Vitamin C deficiency related reduction in carnitine levels results in fatigue and lethargy. Vitamin C is an essential cofactor for the conversion of dopamine to norepinephrine and in the metabolism of tyrosine and folate and the conversion of cholesterol to bile acids. In addition, vitamin C in the diet improves the absorption of non-heme iron, the form of iron present in plant-based foods.9Profound and extended vitamin C deficiency leads to scurvy, a condition that is characterized by blood vessel fragility, connective tissue damage, fatigue, and, ultimately, death.1-13Early symptoms can include weakness, listlessness, as well as shortness of breath and aching joints, bones and muscles. Myalgias occur because of the reduced production of carnitine. Oral complications can include gingival bleeding with minor trauma that proceeds to alveolar bone absorption and tooth loss. Iron deficiency anemia can also occur due to increased intestinal bleeding and decreased non-heme iron absorption.10-13Rheumatologic problems, such as painful hemarthrosis and subperiosteal hemorrhage, may occur.12Cardiac enlargement may occur because of congestive heart failure secondary to high-output anemia. Scurvy manifests when vitamin C intake falls below 10 mg/day for many weeks.10-13Scurvy is rare in developed countries but can still occur in people with limited food variety and in other high risk groups.Under physiological conditions, vitamin C serves as a potent antioxidant and has been shown to regenerate other antioxidants, particularly vitamin E.2,14-16The reduced form of the vitamin, ascorbic acid, is a very effective antioxidant due to its high electron-donating power and ready conversion back to the active reduced form by glutathione.2This antioxidant action plays a role in limiting the damage caused of free radicals produced by normal metabolic respiration and might serve to deter the development of certain cancers, cardiovascular disease, and other diseases.2,14-16Vitamin C concentration has been shown to be inversely associated with all-cause mortality.17,27Low plasma vitamin C concentrations are associated with increased blood pressure16,17and an increased risk of cardiovascular disease9,15,18,21-23and diabetes.24,25The NHANES 2003-2004 revealed that approximately seven percent of the United States population has deficient serum levels of vitamin C (levels below 11 umol/L).28The prevalence of vitamin C deficiency was markedly higher in smokers relative to nonsmokers, possibly due to the increased catabolism associated with the oxidative stress of caused by smoking.2,28Lower vitamin C levels are seen in the institutionalized elderly, possibly due to clinical conditions such as recurrent infections.2Levels are also lower in low-income compared with the high-income persons.28Other at-risk groups include persons with gastroinestinal disease or poor dentition.2,12Cancer patients on chemotherapy who have increased nausea and diarrhea are also at risk, as are patients on hemodialysis.12Psychiatric disorders including depression, schizophrenia, or anorexia, also can put patients at risk for reduced intake of vitamin C.12Alcoholic persons are at risk for scurvy because they may have poorly balanced diets and because decreases the absorption of vitamin C.12

Nutrition & Vitamins, General Health & Wellness

Vitamin A is critical for vision, growth and many cell functions. High concentrations of Vitamin A are seen with renal failure, but this is not associated with toxicity and excessive ingestion. High concentrations are associated with bone fractures. Low concentrations of Vitamin A are consistent with fat malabsorption and are rarely due to inadequate diet.

Nutrition & Vitamins, General Health & Wellness

Beta Carotene, a fat soluble nutrient, is a precursor to vitamin A. Deficiencies may lead to vitamin A deficiency. Excessive vitamin A intake may lead to headaches, loss of appetite, nausea and diarrhea, skin changes, and potential birth defects.

Nutrition & Vitamins, Bone Health

Measurement of serum 25-OH vitamin D concentrations provide a good index of circulating vitamin D activity in patients not suffering from renal disease. Lower than normal 25-OH vitamin D levels can result from a dietary deficiency, poor absorption of the vitamin or impaired metabolism of the sterol in the liver. A 25-OH vitamin D deficiency can lead to bone diseases such as rickets and osteomalacia. Above normal levels can lead to hypercalcemia

Nutrition & Vitamins, Liver & Kidney Health

Prealbumin is decreased in protein-calorie malnutrition, liver disease, and acute inflammation. It may be used as an indicator of nutritional requirements and response to therapy during total parenteral nutrition and as a biochemical marker of nutritional adequacy in premature infants.

Nutrition & Vitamins, General Health & Wellness

Vitamin C is an antioxidant involved in connective tissue metabolism, drug-metabolizing systems, and mixed-function oxidase systems to list a few. Vitamin C deficiency causes scurvy; manifestations include impaired formation of mature connective tissue, bleeding into the skin, weakness, fatigue, and depression.

Nutrition & Vitamins

Zinc is an essential element involved in a myriad of enzyme systems including wound healing, immune function, and fetal development. Zinc measurements are used to detect and monitor industrial,dietary, and accidental exposure to zinc. Also, zinc. measurements may be used to evaluate health and monitor response to treatment.

Nutrition & Vitamins

Studies have demonstrated that IgA endomysial antibody tests have >99% specificity for gluten-sensitive enteropathy.1Recently, the endomysial antigen has been identified as the protein cross-linking enzyme known as tissue transglutaminase (tTG).2

Nutrition & Vitamins

Vitamin B1refers to a group of compounds that include thiamin and its phosphate esters: thiamine monophosphate (TMP), thiamine pyrophosphate (TPP), and thiamine triphosphate.1-5All living organisms require thiamine, but it is only synthesized by bacteria, fungi, and plants. Thus, thiamine is an essential nutrient for animals that must obtain it from their diets. The principal biologically active form of thiamine is the pyrophosphate, TPP, which serves as a coenzyme for essential decarboxylation reactions by which carbohydrates, fats, and alcohol are metabolized to produce energy. Thiamine serves a role in the biosynthesis of acetylcholine and gamma-aminobutyric acid (GABA). TPP also facilitates the production of reducing substances involved in oxidant stress defenses, as well as for the synthesis of nucleic acid precursors.5Thiamine triphosphate serves an important role in the regulation of ion channels of the nervous system.2Primary thiamine deficiency is most common in underdeveloped countries due to poor oral intake or diets consisting of non-enriched grains.1,5-8The most common causes of thiamine deficiency in more affluent countries are alcoholism or malnutrition in nonalcoholic patients.5Secondary thiamine deficiency can occur due to impaired gastrointestinal absorption related to disease or bariatric surgery. Consumption of anti-thiamin enzymes found in raw fish, ferns and betel nuts can reduce the absorption of thiamin.6A relative thiamine deficiency can also occur in patients receiving enteral or parenteral nutrition therapy, in prolonged diarrheas, and in impaired utilization conditions such as in severe liver disease.5Conditions that increase metabolic requirements for thiamine such as hyperthyroidism, pregnancy, lactation, and systemic infections with or without fever have been associated with thiamin deficiency. Increased gastrointestinal or renal losses, especially for patients on hemodialysis, can be a risk factor as well as advanced age, diabetes mellitus, AIDS, malignancies and any critical illness.5,7The earliest symptoms of thiamine deficiency are nonspecific and include fatigue, irritation, poor memory, sleep disturbances, anorexia, abdominal discomfort, and constipation.5Severe thiamin deficiency is rare and can present as congestive heart failure (wet beriberi), peripheral neuropathy (dry beriberi), Wernicke encephalopathy (WE) and/or Korsakoff syndrome.3-5Dry beriberi is characterized by central and peripheral neuropathy that can be permanent even following thiamin repletion.3,4Clinical signs of dry beriberi are bilateral and symmetric, predominantly involving the lower extremities and have been well described in the literature.5The neurological side effects of thiamin deficiency can progress to Wernicke encephalopathy (WE) and Korsakoff psychosis.3,5,7,9This diagnosis denotes the acute cerebral manifestation of severe thiamine deficiency that can lead to irreversible memory loss and dementia.5,7,9Patients with WE present with nystagmus, ophthalmoplegia, mental-status changes, and unsteadiness of stance and gait.9,10Korsakoff psychosis, an irreversible amnestic confabulatory state, can be the initial presentation in some patients, or it may be a sequel to WE.7These patients present with clinical manifestations that are highly variable that can include oculomotor abnormalities, gait disturbance, and global confusion with retrograde amnesia, cognitive impairment, and confabulation.3Wet beriberi refers to a thiamine deficiency condition where impaired cardiac performance leads to systemic symptoms.4,5In the initial stages of wet beriberi, high cardiac output produces peripheral vasodilation with warm extremities and excessive sweating.5As the heart starts to fail further symptoms including tachycardia, a wide pulse pressure and lactic acidosis develop, leading to salt and water retention in the kidneys.5The resulting fluid overload leads to edema of the dependent extremities.5A more rapidly progressing form of wet beriberi has been referred to as acute fulminant cardiovascular beriberi or Shoshin beriberi, in which vasodilation continues, resulting in shock in a patient with heart failure.5The signs and symptoms of wet beriberi and similar to those associated with heart failure from other causes. Several studies have shown that the prevalence of thiamine deficiency is increased in heart failure patients relative to the general population.4,7,11-15It has been postulated that thiamin deficiency may actually exacerbate underlying heart failure symptoms.3,6Research has shown that correction of thiamin deficiency can improve left ventricular ejection fraction, an indicator of long term prognosis in heart failure patients.3,16-18Malnutrition, advanced age, frequent hospitalization, and use of diuretic medications have all been shown to increase the risk of thiamin deficiency in patients with HF.4,7The levels of TPP in plasma or serum are very low relative to the erythrocyte. Plasma contains mainly thiamine and TMP, whereas TPP predominates in erythrocytes.20TPP accounts for 90% of the thiamine content in whole blood.2The TPP concentration in erythrocytes correlates with that in whole blood, a characteristic that allows the use of whole blood, rather than washed erythrocytes, for thiamine assessment.2,19,20Thus, whole blood is the preferred sample type for analysis of thiamine concentration.

Blood Disorders, Nutrition & Vitamins

Offered as part of multiple lab tests

Nutrition & Vitamins, Bone Health

Ionized calcium represents the true "bioavailable" calcium in the circulation. In situations where the total calcium is normal but does not fit the clinical picture, e.g. , hyperparathyroidism, a determination of the ionized calcium will, many times, show an elevation in the "bioavailable" calcium component. This may be due to alterations in protein concentrations, especially albumin, that binds most of the calcium in the circulation.

Nutrition & Vitamins

Vitamin A is critical for vision, growth, and many cell functions. High concentrations of Vitamin A are seen with renal failure, but this is not associated with toxicity and excessive ingestion. High concentrations are associated with bone fractures. Low concentrations of Vitamin A are consistent with fat malabsorption and are rarely due to inadequate diet.

Liver & Kidney Health, Nutrition & Vitamins

This quantitative urea nitrogen test, performed with a 24-hour urine specimen, may help estimate nitrogen balance and determine protein need in patients in critical conditions or receiving intravenous administration of nutrition [1].Urea is the main nitrogen-containing product of protein breakdown and makes up over 75% of total nonprotein nitrogen excreted. Approximately 90% of the urea excretion is through the kidneys, and the rest is through gastrointestinal tract and skin. Because urea secretion is closely related to protein catabolism, urinary urea, commonly expressed by the concentration of urinary urea nitrogen, may be used to assess nitrogen balance and guide protein intake [1,2]. Blood and urinary urea levels were previously used as kidney function markers but are only considered useful in certain clinical scenarios; they have been generally replaced by creatine levels [1].Urinary urea nitrogen level may be increased in individuals with hyperthyroidism or excess protein intake or breakdown [3]. It may be decreased in individuals with malnutrition, kidney damage or insufficiency, low-protein and high-carbohydrate diet, or liver disease. Pregnant persons and healthy children may also have low urinary nitrogen levels [3].The results of this test should be interpreted in the context of pertinent clinical and family history and physical examination findings.References1. Lamb EJ, et al. Kidney function tests. Rifai N, et al. eds.Tietz Textbook of Laboratory Medicine. 7th ed. Elservier Inc; 20222. Oh MS, et al. Evaluation of renal function, water, electrolytes, and acid-base balance. In: McPherson RA, et al, eds.Henry's Clinical Diagnosis and Management by Laboratory Methods. 24th ed. Elsevier; 20213. Rao LV, et al. Laboratory tests. In: Rao LV, eds.Wallach's Interpretation of Diagnostic Tests. Pathways to Arriving at a Clinical Diagnosis. 11th ed. Wolters Kluwer; 2020.

Heart Health & Cardiovascular, Nutrition & Vitamins

An elevated concentration of Homocysteine is an independent risk factor for cardiovascular disease.

Nutrition & Vitamins

This test measures intact parathyroid hormone (PTH) levels in blood and may aid in the differential diagnosis of hypocalcemia and hypercalcemia. This test may also be useful in the diagnosis and management of disorders such as hyperparathyroidism, hypoparathyroidism, hypercalcemia of malignancy, or mineral and bone disorder (MBD) due to chronic kidney disease (CKD) [1-4].PTH measurement is useful for initial evaluation of hypocalcemia, when low or inappropriately normal PTH levels would suggest a lack of adequate PTH secretion (hypoparathyroidism). For differential diagnosis of hypercalcemia, high or inappropriately normal levels of PTH would suggest over-secretion of PTH (hyperparathyroidism or ectopic PTH production), while low levels point to the possibility of hypercalcemia due to a tumor [1,2]. This test may also be helpful in detecting parathyroid disorders caused by chronic calcium and vitamin D deficiency after bariatric surgery [3]. PTH level is recommended as one of the biomarkers to monitor MBD in patients with CKD, starting at CKD stage G3a [4].Because interpretation of a PTH result depends upon the calcium level, a simultaneous blood calcium test needs to be acquired [1,2].This assay uses antibodies directed separately against the N-terminal and C-terminal portions of the PTH molecule, in an immunometric "sandwich" format that detects intact molecules. Therefore, this test is not affected by C-terminal fragments, which can accumulate in renal failure.This immunoassay employs antibodies; therefore, heterophile antibodies in the patient samples may interfere with test results [2].This assay is not affected by most drugs or supplements, including biotin [2].The results of this test should be interpreted in the context of pertinent clinical and family history and physical examination findings.References1. Endres DB, et al. Mineral and bone metabolism. In: Burtis CA, et al. eds.Tietz Textbook of Clinical Chemistry and Molecular Diagnostics. 4th ed. Elserier Inc; 2006:1912-1920.2. Access intact PTH. Instruction for use. Beckman Coulter, Inc; 2020.3. Wei JH, et al.Obes Surg. 2018;28(3):798-804.4. Isakova T, et al.Am J Kidney Dis. 2017;70(6):737-751.

Nutrition & Vitamins

Acute and chronic mercury poisoning affects the kidneys, central nervous system, and the gastrointestinal tract. The three telltale symptoms of mercury poisoning are impaired articulation, irregularity of muscular action, and constricted visual fields. Mercury poisoning through chronic exposure to metallic and inorganic forms of mercury generally produces nervousness, lassitude, tremor, and mucous membrane irritation. Inorganic mercury poisoning is associated primarily with peripheral effects, including gastroenteritis and tubular nephritis, whereas organic compounds predominantly affect the central nervous system (CNS) and effects may be severe and irreversible.2Chronic inorganic mercury poisoning is an occupational disease of smelters, mercury miners, gilders, and factory workers. Inhalation of mercury vapors may lead to pneumonitis, cough, fever, and other pulmonary symptoms. The most reliable way to measure exposure to inorganic mercury is to measure urinary mercury levels. Correlation between urine levels and symptoms is poor, however.The most common nonindustrial source of mercury poisoning is the consumption of methyl mercury-contaminated fish. Organic mercury poisoning is best detected in whole blood, as this form of mercury is located mainly in the RBCs. Organic mercury poisoning may develop quickly and is usually a more serious disease. Studies conducted by the CDC3found that approximately 6% of childbearing-age women had levels at or above a reference dose, an estimated level assumed to be without appreciable harm (>5.8 μg/L). Women who are pregnant or who intend to become pregnant should follow federal and state advisories on consumption of fish.Additional general population exposure to mercury is from coal-fired power plants where an estimated 75 tons of mercury are emitted into the atmosphere each year.4BEI® are reference values intended as guidelines for evaluation of occupational exposure. BEI® represent biological levels of chemicals that correspond to workers with inhalation exposure equivalent to the threshold limit value (TLV®) of the chemicals. TLV®s refer to the airborne concentrations of substances and represent conditions under which it is believed that nearly all workers may be repeatedly exposed, day after day, without adverse health effects.5

Nutrition & Vitamins

Dehydroepiandrosterone (DHEA) is a steroid that is produced by both the adrenal cortex and the testis.3The levels of this steroid increase before the onset of puberty (adrenarche) and decrease significantly with age.4DHEA and DHEA-S are the major precursors of 17-ketosteroids.

Nutrition & Vitamins

Vitamin B1 is required for branched-chain amino acid and carbohydrate metabolism. Vitamin B1 deficiency is most often due to alcoholism or chronic illness. In the early stage, patients with vitamin B1 deficiency exhibit anorexia, irritability, apathy, and generalized weakness. Prolonged deficiency causes beriberi.

Nutrition & Vitamins, Bone Health

Measurement of serum 25-OH vitamin D concentrations provide a good index of circulating vitamin D activity in patients not suffering from renal disease. Lower than normal 25-OH vitamin D levels can result from a dietary deficiency, poor absorption of the vitamin or impaired metabolism of the sterol in the liver. A 25-OH vitamin D deficiency can lead to bone diseases such as rickets and osteomalacia. Above normal levels can lead to hypercalcemia. This assay employs liquid chromatography tandem mass spectrometry to independently measure and report the two common forms of 25-hydroxy vitamin D: 25-OH D3- the endogenous form of the vitamin and 25-OH D2- the analog form used to treat 25-OH Vitamin D3deficiency.

Nutrition & Vitamins, General Health & Wellness

Vitamin B6occurs as an alcohol (pyridoxine), an aldehyde (pyridoxal), and an amine (pyridoxamine). These forms are phosphorylated in the 5'-position to produce the physiologically active coenzymes that are critical to their biological function. Eukaryotes cannot synthesize vitamin B6molecules from smaller compounds and as a result require dietary B6for the synthesis of 5'-phosphate vitamins. Pyridoxal 5'Phosphate (PLP), the most clinically significant coenzyme form of vitamin B6, is the form most commonly measured in plasma.1-3PLP serves as a coenzyme for more than 100 enzymes that catalyze key steps in the metabolism of amino acids, neurotransmitters, nucleic acids, heme and lipids.1,4,5Vitamin B6is a critical cofactor for enzymes involved in energy homeostasis through glycogen degradation and gluconeogenesis.5Inverse associations have been shown between plasma PLP and chronic or acute disease, including rheumatoid arthritis, cardiovascular disease, deep vein thrombosis and cancer.4-16A number of epidemiologic studies have shown reduced concentrations of circulating PLP in association the acute phase marker C-reaction protein13-17and with inflammatory markers.18-19Diminished vitamin B6levels are frequently observed without any indication of a lower dietary intake or excessive catabolism of the vitamin, or congenital defects in its metabolism.4Research is ongoing to determine if these lower vitamin B6levels are caused by the mobilization of this coenzyme to the site of inflammation for use by the PLP-dependent enzymes4or due increased catabolism of vitamin B6during inflammation.5PLP serves as a coenzyme for δ-aminolevulinate synthase, which catalyzes the first step in heme biosynthesis.1,5B6deficiency can produce a hypochromic form of anemia characterized by the presence of ring sideroblasts (iron positive granules deposited about the nucleus of red cell precursors). Occasionally the anemia may have megaloblastic characteristics. Inherited abnormalities of apoenzymes that bind with pyridoxal phosphate are responsible for newborn conditions characterized by intellectual disability, skeletal deformities, thrombotic conditions, osteoporosis and visual defects. Some inherited abnormalities of vitamin B6metabolism and transport are associated with aminoacidurias including homocystinuria, hypermethioninemia and cystathioninuria.21A number of studies have demonstrated an inverse association between plasma PLP levels and the risk of developing colorectal cancer.20A recent meta-analysis indicated that the risk of developing this type of cancer decreased by 49% for every 100-pmol/mL increase in blood PLP level.20Vitamin B6deficiency can occur in individuals with a variety of genetic conditions including antiquitin deficiency,21pyridox(am)ine-5'-phosphate oxidase (PNPO) deficiency22and hyperprolinemia type II (pyrroline-5- carboxylate dehydrogenase deficiency.23Vitamin B6levels can be decreased in malabsorption conditions including inflammatory disease of the small bowel and as a consequence of jejunoileal bypass.4,5Several drugs, including oral contraceptive agents, levodopa, isoniazid, cycloserine and pyrazinoic acid may cause B6depletion.1B6levels may be decreased with pregnancy, lactation and alcoholism.1Infants can develop deficiency when fed formula rendered B6depleted by excessive heating.Markedly elevated plasma PLP levels are observed in cases of hypophosphatasia (HPP), an inborn error of metabolism caused by a loss-of-function mutation(s) within the gene for the cell surface enzyme, tissue nonspecific isoenzyme of alkaline phosphatase (TNSALP).24-28This disorder is characterized by low serum alkaline phosphatase activity and increased plasma levels of TNSALP substrates including inorganic pyrophosphate, phosphatidylethanolamine and PLP. Clinical features can include childhood rickets, adult osteomalacia and dental abnormalities. These symptoms are thought to occur as a result of the accumulation of inorganic pyrophosphate which inhibits hydroxyapatite crystal formation and growth, leading to defective skeletal and dental mineralization. PLP, carried in the plasma on albumin, must be de-phosphorylated by TNSALP for pyridoxal to cross cell membranes. Once inside the cell, the pyridoxal is regenerated as PLP to allow it to function as a coenzyme. The diminished TNSALP of individuals with HPP leads to an accumulation of the PLP substrate in plasma. HPP patients do not typically experience B6related symptoms. However, the extent of PLP elevation has been related to the disease severity.28

Heart Health & Cardiovascular, Nutrition & Vitamins

An elevated concentration of homocysteine is an independent risk factor for cardiovascular disease. When used in conjunction with methylmalonic acid (MMA), these tests are useful to diagnose and monitor vitamin B12 (cobalamin) and folic acid deficiency and are often useful in evaluating macrocytosis (an elevated MCV, an erythrocytic index).

Nutrition & Vitamins

MMA is a four-carbon molecule that is a product of the metabolic break-down of valine, isoleucine, and propionic acid.1Vitamin B12 is a critical cofactor for the conversion of MMA to succinate.1As a result, vitamin B12deficiency causes an accumulation of MMA in the serum.1MMA concentrations will often become elevated in the early stages of vitamin B12while serum vitamin B12levels are in normal range.1-4Consequently, MMA measurement is used as a diagnostic test for vitamin B12deficiency in persons with a low or low normal serum vitamin B12concentration.5,6Follow-up measurement of MMA can also be of value in assessing the effectiveness of vitamin B12supplementation of deficient patients.7Vitamin B12deficiency causes macrocytic anemias and decreased erythrocyte survival due to abnormal maturation of erythrocyte precursors in the bone marrow.10,11Pernicious anemia is a form of vitamin B12deficiency that is caused by a lack of intrinsic factor.10,11Low vitamin B12intake, gastrectomy, malabsorption, and transcobalamin deficiency can also cause vitamin B12deficiency.10,11Although severe vitamin B12deficiency is associated with anemia, hematologic signs are not always observed in patients with biochemically confirmed deficiency.12Elderly patients with cobalamin deficiency may present with peripheral neuropathy, ataxia, memory impairment, depression, and dementia in the absence of anemia.13,14A generally agreed on cutoff for elevated plasma MMA is 370 nmol/L.6,12Approximately 2% of the US population and 7% of elderly persons have MMA concentrations above this threshold.12

Nutrition & Vitamins

Children with thalassemia may have normal phosphorus absorption, but high renal phosphaturia, leading to a deficiency of phosphorus.2Increasing dietary intake of potassium has been reported to increase serum phosphate concentrations apparently by decreasing renal excretion of phosphate.3During the last trimester of pregnancy there is a sixfold increase in calcium and phosphorus accumulation as the fetus triples its weight. Plasma phosphorus concentrations and increased urinary phosphate may provide a useful means to assess response to phosphate supplements in the premature infant.4

Nutrition & Vitamins, Blood Disorders

Folate levels have diagnostic significance in nutritional deficiencies, especially in cases of severe alcoholism, function damage to the upper third of small bowel, pregnancy and various forms of megoblastic anemia. Since serum folate levels are subject to rapid changes reflecting diet and absorption, RBC folate may be a better diagnostic tool since the levels remain fairly constant.

Heavy Metals & Toxins, Nutrition & Vitamins

Offered as part of multiple lab tests

Heavy Metals & Toxins, Nutrition & Vitamins

Chromium exposure through the inhalation of insoluble chromium compounds may produce pneumoconiosis with impairment of pulmonary function. Exposure to the inorganic soluble salts can precipitate skin ulcerations, dermatitis, perforation of the nasal septum, and respiratory sensitization. Acute exposure to these salts may result in local tissue necrosis and severe kidney damage.2Chromium and its inorganic salts are widely employed in industry, including metal plating, steel and nonferrous alloys, refractory materials, and chromate pigments and preservatives. In organic forms, chromium is also an essential nutrient for man supplied in the diet (5−115 μg/day); however, overexposure is generally associated with the industrial environment, specifically through the inhalation of chromium dust and fumes.BEI® are reference values intended as guidelines for evaluation of occupational exposure. BEI® represent biological levels of chemicals that correspond to workers with inhalation exposure equivalent to the threshold limit value (TLV®) of the chemicals. TLVs refer to the airborne concentrations of substances and represent conditions under which it is believed that nearly all workers may be repeatedly exposed, day after day, without adverse health effects.3

Nutrition & Vitamins

Offered as part of multiple lab tests

Nutrition & Vitamins, Diabetes & Blood Sugar

Plasma or serum NEFA is the portion of the total fatty acid pool that circulates in immediate readiness for metabolic needs. NEFA can be absorbed readily by muscle, heart, brain, and other organs as an energy source whenever insufficient quantities of glucose limit the usual carbohydrate energy source. In all probability, both glucose and NEFA are simultaneously taken up from the blood, even under normal conditions. When blood glucose levels are high, the NEFA level falls, and vice versa, emphasizing the reciprocal withdrawal of stored energy, under the simultaneous control of insulin and epinephrine. In acute starvation, the NEFA level may rise as much as three times the normal values.

Nutrition & Vitamins

Tissue Transglutaminase Antibody, IgA, is useful in diagnosing gluten-sensitive enteropathies, such as Celiac Sprue Disease, and an associated skin condition, dermatitis herpetiformis.

Nutrition & Vitamins

Hypercalcemia, hypophosphatemia and acidosis are among inhibitors of tubular reabsorption of magnesium.2

Nutrition & Vitamins

Useful in the assessment of nutritional and metabolic disorder. Increased levels indicate renal and respiratory failure and decreased levels indicate seizures, tetany, cardiac arrhythmias, Low CA++ and K+.

Nutrition & Vitamins

Vitamin B2 is involved in metabolism of fats, carbohydrates, and protein. The clinical manifestations of deficiency are non-specific. Clinical manifestations include mucocutaneous lesions of the mouth and skin, corneal vascularization, anemia, and personality changes.

Heavy Metals & Toxins, Nutrition & Vitamins

Cobalt poisoning through chronic exposure may result in pulmonary fibrosis, cough, and dyspnea. Acute exposures are generally characterized by an allergic dermatitis.2Cobalt is employed industrially in certain grades of steel and in tungsten carbide tools, and cobalt compounds are used as pigments in paints. In addition, cobalt is an essential element in man, supplied through dietary intake at an average of 280 μg/day. Although cobalt is found in the general environment, overexposure typically occurs in the industrial environment, primarily through the inhalation of cobalt dust and/or fumes. Cobalt exposure can also occur as a result of ingesting medications such as cobaltous chloride. Blood is the preferred specimen for measuring acute or recent exposure.

Nutrition & Vitamins, Heavy Metals & Toxins

Copper is an essential element that is a cofactor of many enzymes. Copper metabolism is disturbed in Wilson's disease, Menkes disease, primary biliary cirrhosis, and Indian childhood cirrhosis. Urinary copper concentrations are also useful to monitor patients on chealation therapy.

Nutrition & Vitamins

Deficiency of Vitamin E may cause extensive neuropathy in young children and, in addition, is suspect as a possible cause of motor and sensory neuropathy in older children and in adults. One likely cause of Vitamin E deficiency is intestinal malabsorption, resulting from bowel disease, pancreatic disease, or chronic cholestasis. Other causes of malabsorption of Vitamin E include celiac disease, cystic fibrosis, and intestinal lymphangiectasia.

Heavy Metals & Toxins, Nutrition & Vitamins

Offered as part of multiple lab tests

Nutrition & Vitamins, Bone Health

Humans get vitamin D from their normal diet, dietary supplements and from exposure to sunlight.1-5Ultraviolet B irradiation of the skin drives the conversion of 7-dehydrocholesterol to previtamin D3, which is then rapidly converted to vitamin D3.1Vitamin D from the skin and diet is further metabolized in the liver to 25-(OH) vitamin D (or calcidiol).1-5Calcidiol is the principle circulating reservoir of vitamin D in plasma and is generally the best indicator of overall vitamin D status. Calcidiol is further converted by the enzyme 25-(OH) D-1α-hydroxylase (CYP27B1) in the proximal tubules of the kidney to the biologically active form of vitamin D, 1,25-(OH)2 vitamin D (or calcitriol).1-5The renal production of calcitriol is tightly regulated by plasma parathyroid hormone (PTH)1-5and fibroblast growth factor 23 (FGF-23). FGF-23 is a circulating hormone synthesized by osteocytes and osteoblasts.5-8Calcitriol and phosphate intake stimulates the synthesis of FGF-23, which, in turn, suppresses calcitriol synthesis and activates calcitriol conversion to inactive metabolites.1-6Calcitriol is a steroid-like hormone that binds to a specific cytoplasmic vitamin D receptor (VDR) in the cytoplasm of target cells. The calcitriol-VDR complex then migrates into the nucleus, where its effects are mediated at a transcriptional level.5Renal production of calcitriol is important in the regulation of serum calcium homeostasis and in the maintenance of healthy bone.1,2,9-11Calcitriol stimulates the absorption of calcium and phosphate by the intestine and increases calcium and phosphate resorption by the kidney.1-6,12,13Calcitriol also suppresses PTH production and regulates osteoblast function and bone resorption.5It has been suggested that calcitriol has roles beyond the calcium-skeletal axis.1-5,14Vitamin D deficiency can affect the production of calcitriol owing to the lack of substrate. A positive correlation between serum levels of calcidiol and calcitriol was observed during seasonal changes. Treatment with calcidiol can normalize calcitriol concentrations in patients with vitamin D deficiency.12,15,16Calcitriol assessment may be beneficial in patients with chronic kidney failure. Diminished levels of calcitriol can be seen in patients with kidney failure due to reduced 1α-hydroxylase activity and phosphate retention resulting in increased FGF-23 levels.17,18Impaired calcitriol production plays a major role in the development of secondary hyperparathyroidism as calcitriol deficiency promotes parathyroid gland hyperplasia and increased parathyroid hormone (PTH) synthesis due to the loss of the ability to upregulate vitamin D receptor expression within parathyroid cells.19This ultimately results in elevated serum PTH and abnormal calcium and phosphorus balance.Calcitriol measurement may be of use in patients with early-onset rickets or a family history of rickets. Serum calcitriol levels can also be increased in patients with hereditary vitamin D-resistant rickets, a very rare autosomal recessive disorder in which mutations of vitamin D receptor (VDR) impair calcitriol binding to the VDR.20Patients usually present with hypocalcemia, early-onset rickets, alopecia, and other ectodermal anomalies.20Other heritable disorders associated with low calcitriol levels include vitamin D–dependent rickets type 1 (inactivating mutation in the 1-hydroxylase gene),21autosomal-dominant hypophosphatemic rickets (mutation of the gene coding for FGF-23, which prevents its breakdown),22and X-linked hypophosphatemic rickets (mutations that elevate levels of FGF-23).23Individuals treated with glucocorticoids or anticonvulsants are at risk of hypocalcemia associated with a low concentration of calcitriol. HIV protease inhibitors have been reported to markedly suppress calcitriol synthesis24,25In tumor-induced osteomalacia, tumor-secreted FGF-23 inhibits enzyme 1α-hydroxylase and subsequently results in decreased calcitriol synthesis.26Calcitriol may also be helpful in the diagnosis of parathyroid function disorders. A high serum level of calcitriol, for example, may suggest of primary hyperparathyroidism, whereas a normal or low serum level is more likely found in secondary hyperparathyroidism. Increased calcitriol levels can be seen in some individuals with lymphoproliferative disorders and granulomatous disease including, sarcoidosis, tuberculosis, and inflammatory bowel disease where increased macrophage activity is associated with extrarenal 1α-hydroxylase enzyme activity.27However, unlike the kidney, the 1α-hydroxylase activity in the macrophages is not controlled by the usual physiologic regulators.14,28

Nutrition & Vitamins, Bone Health

This test measures the bioactive form of vitamin D. It is used in the differential diagnosis of hypocalcemia and to monitor patients with renal osteodystrophy or chronic renal failure. This test is not suitable for diagnosis of vitamin D deficiency and monitoring supplementation in most patients. The 25-hydroxyvitamin D test is the recommended test for those purposes (N Engl J Med. 2007;357:266-281).

Nutrition & Vitamins

BEI® are reference values intended as guidelines for evaluation of occupational exposure. BEI® represent biological levels of chemicals that correspond to workers with inhalation exposure equivalent to the threshold limit value (TLV®) of the chemicals. TLVs refer to the airborne concentrations of substances and represent conditions under which it is believed that nearly all workers may be repeatedly exposed, day after day, without adverse health effects.1

Nutrition & Vitamins

Offered as part of multiple lab tests

Nutrition & Vitamins

Iodine is an essential element that is required for thyroid hormone production. The measurement of iodine serves as an index of adequate dietary intake and iodine overload, particularly from iodine-containing drugs such as Amiodarone.

Nutrition & Vitamins

Offered as part of multiple lab tests

Nutrition & Vitamins

Offered as part of multiple lab tests

Nutrition & Vitamins

The presence of anti-endomysial (EMA) IgA antibodies has been shown to correlate with gluten-sensitive enteropathy such as celiac disease (CD) and dermatitis herpetiformis (DH). EMA is detected primarily by IFA, using monkey esophagus as a substrate and observing fluorescence of the endomysial lining. Patients with CD and DH can also demonstrate antibodies to reticulin and gliadin, though EMA-IgA seems to be the most specific marker (specifically 94-100%).

Nutrition & Vitamins

Mercury, a highly toxic metal, is present in select industrial environments and in contaminated ocean fish. Urinary measurements are appropriate for assessing ongoing exposure to inorganic mercury.

Nutrition & Vitamins

Iodine is an essential element that is required for thyroid hormone production. The measurement of urinary iodine serves as an index of adequate dietary intake.

Heavy Metals & Toxins, Nutrition & Vitamins

Zinc protoporphyrin (ZPP) accumulates in erythrocytes as a result of chronic lead absorption or iron deficiency anemia.

Heavy Metals & Toxins, Nutrition & Vitamins

Mercury, a highly toxic metal, is present in select industrial environments and in contaminated ocean fish.

Heavy Metals & Toxins, Nutrition & Vitamins

Offered as part of multiple lab tests

Nutrition & Vitamins

CoQ10 deficiency syndromes are quite rare and are clinically and genetically heterogeneous.4These conditions have been classified into five major clinical phenotypes: 1. encephalomyopathy; 2. severe infantile multisystemic disease; 3. cerebellar ataxia; 4. isolated myopathy; and 5. nephrotic syndrome. In some cases, specific mutations have been identified in genes involved in the biosynthesis of CoQ10 (primary CoQ10 deficiencies) or in genes not directly related to CoQ10 biosynthesis (secondary CoQ10 deficiencies.4Respiratory chain defects, reactive oxygen species production, and apoptosis are variably characteristics of primary CoQ10 deficiencies.5Several of these conditions are responsive to CoQ10 administration.6CoQ10 is endogenously synthesized via the mevalonate pathway, and some is obtained from the diet with meat products being the principal source.2CoQ10 supplements are available over the counter.2Due to its lipophilic nature, CoQ10 is transported in lipoprotein particles in the circulation and plasma levels tend to correlate with serum total and LDL-cholesterol.2Statins lower blood cholesterol levels by inhibiting HMG-CoA reductase, the rate-limiting enzyme in the biosynthesis of cholesterol.2,7This same enzyme is involved in the biosynthesis of CoQ10 through the mevalonate pathway. Plasma CoQ10 concentrations are reduced in patients receiving statin therapy.2The magnitude of CoQ10 decline is dose related and can be reversed by discontinuing therapy.2It has been postulated that the drop in plasma levels may, in part, reflect by the statin-induced reduction in LDL cholesterol containing particles in the blood stream. The reduction in these lipid particles reduces capacity of the plasma to carry the hydrophobic CoQ10 molecules.2Alternatively, the lower plasma levels may reflect diminished synthesis of CoQ10 as the result of statin inhibition of HMG-CoA.2,7A number of studies have reported a drop in the CoQ10 to LDL-cholesterol ratio in plasma after statin treatment.2This supports the conjecture that CoQ10 depletion is caused by diminished production as well as decreased LDL carriers.2Statins are generally well tolerated. However, their use has been associated with muscle complaints (myopathy) that range from clinically benign myalgia to more serious myositis, and in rare cases, life-threatening rhabdomyolysis. A variety of mechanisms have been proposed to explain statin-induced myopathy with some proposing that the symptoms may be caused by mitochondrial dysfunction resulting from depletion of CoQ10.7The results of a recent meta-analysis of available randomized controlled trials do not suggest any significant benefit of CoQ10 supplementation in improving statin-induced myopathy.9CoQ10 supplementation is commonly used in clinical practice in the treatment of patients with chronic heart failure, male infertility, and neurodegenerative disease.1,6,10,11Recent findings point to a role of CoQ10 in improving endothelial function in cardiovascular disease.6A meta-analysis of clinical trials found that CoQ10 supplementation significantly reduced diastolic pressure in hypertensive patients.8Clinical studies are ongoing related to the effectiveness of CoQ10 supplementation in the treatment of a number of neurodegenerative diseases including Parkinson's disease, Huntington's diseases and Friedreich's ataxia.6CoQ10 has been found to improve sperm count and motility.6CoQ10 treatment has also been found to be useful in other conditions ranging from decreasing the incidence of preeclampsia in pregnancy to mitigating headache symptoms in adults and children with migraine.6

Nutrition & Vitamins

CoQ10 testing is useful for individuals on statin therapy who may or may not be experiencing myalgia symptoms, hypercholesterolemic individuals, and asymptomatic individuals at risk for vascular disease who may have low ApoA1 and/or HDL levels.

Nutrition & Vitamins

Vitamin K serves as a critical cofactor for the post-translational carboxylation of glutamate residues of a number of proteins.4-7Gamma carboxylated glutamate (Gla) residues act as calcium-binding moieties and are essential for the function of these proteins. Profound vitamin K deficiency, caused by inadequate dietary intake or malabsorption, is an acute, life-threatening condition associated with excessive bleeding. Gla-containing coagulation factors II, VII, IX, and X, and proteins C and S, play critical roles in hemostasis.8The Gla-proteins involved in blood coagulation are all synthesized in the liver. Several more recently discovered Gla-proteins that are synthesized in a wide variety of tissues serve roles in metabolic processes beyond coagulation. These proteins include osteocalcin, matrix Gla-protein (MGP), and growth arrest sequence-6 protein (Gas6) that serve key roles in maintaining bone strength, arterial calcification inhibition, and cell growth regulation, respectively. Many individuals with fully gamma-carboxylated coagulation factors have incomplete gamma-carboxylation of extra-hepatic Gla-proteins. It has been postulated that individuals with less than optimal dietary supply of vitamin K synthesize all clotting factors in their active form, whereas the gamma-carboxylation of other Gla-proteins is incomplete. This concept implies that prolonged sub-clinical vitamin K deficiency maybe a risk factor for conditions beyond bleeding, including osteoporosis and atherosclerosis.Vitamin K is not a single compound, but rather a family of related compounds that all share a methylated naphthoquinone ring structure called menadione, substituted at the 3-position with a variable aliphatic side chain.7,9-11Vitamin K1 (also referred to as phylloquinone) is produced in plants and has a side chain that is composed of four isoprenoid residues, the last three of which are unsaturated. Green leafy vegetables such as spinach, broccoli, Brussels sprouts, and kale are especially good sources of vitamin K1. Vitamin K1 provides approximately 90% of the total vitamin K in the western diet.7Oral anticoagulant drugs derived from coumarin block recycling of vitamin K to the form that is required as a cofactor for catalyzing the gamma carboxylation of proteins.11Despite the worldwide use of vitamin K antagonist drugs, there continues to be some uncertainties about the influence of dietary vitamin K on anticoagulation control.12-14The recommended dietary allowance for vitamin K intake is based on the hepatic requirement for clotting factor synthesis. Vitamin K deficiency in early infancy can cause of intra-cranial bleeding.12Newborn babies are at particular risk of vitamin K deficiency due to poor placental transfer and low levels of vitamin K in breast milk.6Vitamin K prophylaxis at birth effectively prevents vitamin K deficiency bleeding (VKDB), also referred to as hemorrhagic disease of the newborn.6,10,15,16Some studies suggest that vitamin K intake above that required to maintain effective hemostasis may be needed to achieve an optimal extra-hepatic vitamin K status.6,17In 2001, the US Food and Nutrition Board concluded that there was insufficient data with which to establish a Recommended Daily Allowance (RDA) for vitamin K, in large part because of a lack of non-hemostatic endpoints that reflected adequacy of intake.10The gamma-carboxylation of the Gla proteins in bone is required to bind calcium and to incorporate calcium into hydroxyapatite crystals of bone.18The most highly studied of the known bone-related Gla-proteins is osteocalcin (OC).18Vitamin K insufficiency is associated with an increase in the concentration of circulating under-carboxylated osteocalcin.18Several clinical studies have reported favorable associations between vitamin K intake and bone health.9,18Other studies have suggested that vitamin K insufficiency may be associated with low bone mineral density and increased incidence of fractures.18Matrix Gla-protein (MGP) is a vitamin K dependent Gla-protein found in bone, as well as in heart, kidney, and lung.18MGP plays a role in the organization of bone tissue and serves as a potent inhibitor of arterial calcification. Incomplete carboxylation of MGP has been associated with an increased risk for developing vascular calcification.4In healthy individuals, substantial fractions of osteocalcin and MGP circulate as incompletely carboxylated species, indicating that the majority of these individuals is sub-clinically vitamin K-deficient.4Osteoporotic bone loss and vascular calcification are associated with treatment with oral anticoagulants, ostensibly due to the impairment of Gla-protein gamma carboxylation.4

Nutrition & Vitamins, Blood Disorders

Vitamin K is a required co-factor for the synthesis of factors 2, 7, 9, and 10 and proteins C and S. Deficiencies of vitamin K lead to bleeding. Coumadin® (warfarin) acts as an anticoagulant because it is a vitamin K antagonist.

Nutrition & Vitamins, Blood Disorders

The Methylmalonic Acid (MMA) test is used in the diagnosis of acquired cobalamin (vitamin B12) deficiency in adults and to screen for inherited organic acidemia in neonates and infants. Elevated MMA in either blood or urine indicates vitamin B12 deficiency in adults, with MMA acting as a functional biomarker for vitamin B12 status. In neonates and infants, elevated MMA is associated with inborn errors of metabolism.Adults with signs and symptoms of cobalamin deficiency, including peripheral neuropathy, ataxia, memory impairment, depression, behavioral changes, and anemia, should be tested for MMA, especially if they are elderly or have experienced intestinal malabsorption or digestive disorders [1]. In the United States all newborns should be screened for MMA as part of the Department of Health and Human Services (HHS) Recommended Universal Newborn Screening Panel [1].MMA can be acquired due to underlying medical conditions that lead to B-vitamin deficiencies or inherited as an autosomal recessive inborn error of metabolism. If a neonate or infant has elevated MMA suggestive of an organic acidemia, the parents may elect to undergo carrier testing, or have their other children undergo genetic testing. Siblings of a child with MMA-related mutation have a 25% chance of being affected and a 50% chance of being a carrier [2].References1. Department of Health and Human Services. Recommended Uniform Screening Panel.https://www.hrsa.gov/advisory-committees/heritable-disorders/rusp/index.html. Updated February 2019. Accessed July 2019.2. Manoli, et al. Isolated methylmalonic academia. Updated: December 1, 2016. In: Adam MP, Ardinger HH, Pagon RA, et al. editors. GeneReviews [Internet]. Seattle (WA)L University of Washington

Nutrition & Vitamins

Offered as part of multiple lab tests

Nutrition & Vitamins

Selenium is an element of parenteral nutrition. Monitoring the Selenium concentration is useful in assessing parenteral nutrition, especially recent intake. Concentrations are also monitored in children with propionic acidemia who require special diets with supplements.

Nutrition & Vitamins, Blood Disorders

Methylmalonic Acid (MMA) is useful to diagnose and monitor Vitamin B12(cobalamin) deficiency, and to diagnose and monitor patients with methylmalonic acidemia.

Nutrition & Vitamins

Copper is an essential element that is a cofactor of many enzymes. Copper metabolism is distributed in Wilson's disease, Menkes disease, primary biliary cirrhosis, and Indian childhood cirrhosis. Copper concentrations increase in acute phase reactions. Copper concentrations are decreased with nephrosis, malabsorption, and malnutrition. Copper concentrations are also useful to monitor patients, especially preterm newborns, on nutritional supplementation. Results of copper are often interpreted together with ceruloplasmin.

Nutrition & Vitamins, Bone Health

Measurement of serum 25-OH vitamin D concentrations provide a good index of circulating vitamin D activity in patients not suffering from renal disease. Lower than normal 25-OH vitamin D levels can result from a dietary deficiency, poor absorption of the vitamin or impaired metabolism of the sterol in the liver. A 25-OH vitamin D deficiency can lead to bone diseases such as rickets and osteomalacia. Above normal levels can lead hypercalcemia. This assay employs liquid chromatography tandem mass spectrometry to independently measure and report the two common forms of 25-hydroxy vitamin D: 25OH D3- the endogenous form of the vitamin and 25OH D2- the analog form used to treat 25OH Vitamin D3deficiency.

Nutrition & Vitamins

Offered as part of multiple lab tests

Nutrition & Vitamins

Biotin is a colorless, water-soluble B-complex vitamin that is also referred to as vitamin B7.1-3Biotin functions as a cofactor for five mammalian enzymes that catalyze specific carboxylation reactions.2These are:• Acetyl-CoA carboxylase I and II: catalyze the carboxylation of acetyl CoA to form malonyl CoA which, in turn, serves as a substrate for fatty acid elongation. These enzymes function in cytosolic fatty acid synthesis and in regulating mitochondrial fatty acid oxidation.• Pyruvate carboxylase: catalyzes the carboxylation of pyruvate to form oxaloacetate, which serves as an intermediate in the citric acid cycle. This reaction is involved in gluconeogenesis, the production of glucose from other carbohydrates by the liver, kidney, and other gluconeogenic tissues.• Methylcrotonyl-CoA carboxylase: catalyzes an essential step in the catabolism of leucine, an essential, branch-chained amino acid.• Propionyl-CoA carboxylase: catalyzes essential steps in the metabolism of several amino acids, cholesterol, and odd chain fatty acids.1Biotin is also covalently attached to histone proteins that are essential for the folding of DNA into chromatin. It has been suggested that the biotinylation of histones might play a role in cell proliferation, gene silencing, and cellular response to DNA damage.4Clinically advanced biotin deficiency is rare in the general population; however, significant biotin deficiency can occur in individuals who consume raw egg white over long periods.1,2Avidin, an antimicrobial protein found in egg white, binds biotin and prevents its absorption. Cooking egg white denatures avidin and wipes out its biotin-binding capacity.1Profound biotin deficiency can also occur in cases of drastically diminished biotin absorption (patients taking total parenteral nutrition without biotin and in some malabsorption conditions).1,2Some forms of liver disease may increase the requirement for biotin and result in clinical deficiency.1,5Patients receiving long-term anticonvulsant medication may also be at increased the risk for biotin deficiency.1,2The results of several studies suggest that biotin deficiency may also be relatively common during pregnancy.1,6Physical findings associated with overt biotin deficiency include a red scaly rash around the eyes, nose, mouth, and genital area.1-3,7Some reports suggest that biotin deficiency may result in brittle finger nails and that high dose supplementation may, to some extent, ameliorate the condition.1,2,7Adults with this deficiency experience thinning of hair, frequently with loss of hair color. Reported neurologic symptoms have included depression, lethargy, hallucination, and paresthesia of the extremities. Individuals with hereditary disorders of biotin metabolism also suffer from impaired immune system function and susceptibility to bacterial and fungal infections.1-3,8

Nutrition & Vitamins

Carcinoid tumors are slow-growing neuroendocrine tumors derived from enterochromaffin cells that are widely distributed throughout the body.1-4Approximately 65 percent of carcinoid tumors are found in the gastrointestinal tract from the foregut, midgut, and hindgut, and another 25 percent originate in the bronchopulmonary tract.3,4The primary site for one in 10 cases remain undetermined.3About a quarter of cases present with distant metastases, half of which have unknown primary tumor location.3Carcinoid tumors secrete a variety of peptides and small molecules.1,4-6Midgut carcinoid tumors frequently produce serotonin. Serotonin secreting carcinoids from other locations are less common. Serotonin (5-hydroxytryptamine) is synthesized from the essential amino acid tryptophan via the intermediate 5-hydroxytryptophan (5-HTP). Serotonin secretion in the gut causes an increase in gastrointestinal blood flow, motility, and fluid secretion. In healthy individuals, the great majority of serotonin made by the gut is converted by the liver and lungs to 5-hydroxyindoleacetic acid (5-HIAA) via first pass metabolism prior to entering the general circulation. Almost the entirety of the small amount of serotonin that survives the first pass metabolism is taken up by platelets. Platelets store serotonin until it is released as part of the clotting process to promote platelet aggregation.Serotonin secreting carcinoid tumors are relatively slow growing, and in most cases, asymptomatic.1,4,6The local, paracrine effect of increased serotonin on the gut intestine can cause diarrhea, malabsorption and tumor mass producing discomfort.4,7Since most serotonin produced by carcinoid tumors is metabolized prior to reaching the circulation, the metabolic product, 5-HIAA, in urine is usually the most important marker for carcinoid tumors.4In cases where a larger amount of serotonin reaches the systemic circulation (advanced disease with liver metastases bypassing first pass metabolism), patients can present with a constellation of symptoms referred to as the carcinoid syndrome. The carcinoid syndrome can also occur in the absence of liver metastases in cases where tumor pathology causes direct venous drainage of serotonin bypassing first pass liver metabolism.5,8Carcinoid syndrome is relatively rare and is most commonly associated with midgut carcinoid tumors.2,4Carcinoid syndrome occurs in 20% of cases of well-differentiated endocrine tumors of the jejunum or ileum.5,8Carcinoid syndrome occurs less often with neuroendocrine tumors of other origins and is very rare in association with rectal NETs.5,8Carcinoid syndrome is characterized by one or more symptoms including diarrhea, dry flushing without sweating with or without palpitations, and intermittent abdominal pain.5Some patients also experience lacrimation and rhinorrhea.5,8Advance or long-standing carcinoid syndrome can lead to carcinoid heart disease involving the tricuspid and pulmonary valves of the heart.7,9Other cardiovascular complications include bowel ischemia and hypertension.7Approximately one in five patients with carcinoid syndrome sent with heart disease at diagnosis.5,8Carcinoid tumors are classified similarly whether they produce symptoms of the carcinoid syndrome or not.10The primary laboratory tests for the diagnosis and assessment of carcinoid tumors are serum chromogranin A and, in the case of tumors presenting with carcinoid syndrome, urinary 5-HIAA. Direct measurement of serotonin is considered a secondary test for this condition.14-16Whole blood serotonin is measured because most circulating serotonin is contained in platelets and whole blood levels correlated with platelet levels. Alternatively, serum serotonin levels can be measured because the process of blood clotting causes the release of all platelet serotonin in to the serum.In healthy individuals, approximately 99 percent of dietary tryptophan is metabolized by the oxidative pathway into nicotinic acid (vitamin B3).4In carcinoid tumors, excessive conversion of tryptophan to serotonin can cause result in vitamin B3 deficiency referred to as pellagra, a condition that is characterized by the triad of symptoms; diarrhea, dementia, and dermatitis.11

Liver & Kidney Health, Nutrition & Vitamins

A serum protein electrophoresis should be reviewed concurrently if one has not been recently studied. In nonselective glomerular proteinuria, the urine electrophoretic pattern is often a nonspecific one which may be called “mirror image” to that of the serum. Contamination of the urine with blood can give a similar pattern. With selective glomerular permeability, albumin, α1-proteins, and transferrin are the predominant proteins identified on the urine protein electrophoresis, with a relative absence of heavier molecular weight proteins (ie, α2-macroglobulin and immunoglobulins). With tubular proteinuria, low molecular weight proteins (α2- and β2-microglobulins) are predominant, with trace amounts of albumin. So called “overflow proteinuria” occurs when low molecular weight proteins are filtered through the glomerulus in increased amounts.

Nutrition & Vitamins

Offered as part of multiple lab tests

Nutrition & Vitamins

This test is used to analyze the protein content in urine. The proteins are separated into 5 major components: albumin, alpha-1, alpha-2, beta, and gamma. Interpretation of elevations, decreases, or visual changes in different components and/or associated patterns can provide information on various disease states, including inflammatory diseases, autoimmune diseases, different types of kidney injury, plasma cell disorders, and cancers [1,2].UPEP is used to evaluate an individual with symptoms associated with potential monoclonal gammopathy, or when an individual has abnormally high total protein, albumin, or immunoglobulin levels. This test can help with initial diagnosis, as well as monitoring disease progression and treatment effectiveness [1,2].Although a 24-hour UPEP (test code 750) is recommended for diagnosis and monitoring, sometimes a random UPEP (test code 8525) is ordered at the discretion of the clinician to help guide the diagnostic process in the right direction. One advantage of a UPEP is that no special handling is required, which may be an important factor depending on clinical conditions.NOTE: The results of this test should not be used in isolation; these results alone are not enough to make a diagnosis or for monitoring. UPEP results should be evaluated along with other laboratory, clinical, and imaging findings as appropriate. Additional testing, such as bone marrow studies, serum protein electrophoresis (SPEP), and immunofixation (IFE), may be required for comprehensive evaluation [1,2].References1. National Comprehensive Cancer Network. NCCN Clinical Practice Guidelines in Oncology. Multiple myeloma. Version 2.2020; October 9, 2019.https://www.nccn.org2. Rajkumar SV, et al.Lancet Oncol. 2014;15:e538-e548.

Bone Health, Nutrition & Vitamins

The bone-specific alkaline phosphatase (BSAP) assay provides a general index of bone formation and a specific index of total osteoblast activity. BSAP and osteocalcin are the most effective markers of bone formation and are particularly useful for monitoring bone formation therapies and antiresorptive therapies.

Nutrition & Vitamins, Heavy Metals & Toxins

Selenium toxicity may occur due to industrial exposures or through drinking water in some parts of the world. Toxic symptoms include garlic breath odor, thick brittle fingernails, dry brittle hair, red swollen skin of the hands and feet, and nervous system abnormalities of numbness, convulsions, or paralysis.1Selenium is produced as a byproduct of copper refining and is used in electronic semiconductors, as a decolorizing agent for ceramics and glass, and as a vulcanizing agent in the rubber industry. The essential nature of selenium in human nutrition is now beyond dispute. Multiple cases of selenium deficiency have been reported in patients receiving parenteral nutrition for longer than one week when no selenium was included in their formula. Deficiency has also been reported in severe malnutrition without parenteral nutrition. The syndrome has included painful weak muscles and acute or chronic congestive heart failure due to cardiomyopathy that is sometimes fatal. Other findings noted in some cases of selenium deficiency include erythrocyte macrocytosis, depigmentation of skin and hair, and elevated transaminase and creatine kinase levels.

Nutrition & Vitamins

Offered as part of multiple lab tests

Nutrition & Vitamins

Offered as part of multiple lab tests

Nutrition & Vitamins

Vitamin B2 refers to a family of water-soluble flavin vitamins that are critical for metabolism and energy generations in the aerobic cell, through oxidative phosphorylation.1-4These compounds are synthesized in plants and microorganisms and occur naturally in three forms: the physiologically inactive riboflavin, and the physiologically active coenzymes flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD). FAD accounts for about 90% of the total riboflavin in tissues. Because of their capacity to transfer electrons, FAD and FMN are essential for proton transfer in the respiratory chain, for the dehydration of fatty acids, the oxidative deamination of amino acids, and for other redox processes.1-4The effects of riboflavin deficiency on growth and development have generally been explained in terms of these functions. Flavin derivatives ingested with the diet (FAD, FMN) are dissociated by gastric acid from their protein binding, transformed by phosphatases to riboflavin, and absorbed in the small intestines.1,2The reconversion of riboflavin to the coenzymes FMN and FAD occurs in the cytoplasm in many different tissues.Vitamin B2 deficiency is common in many parts of the world, particularly in developing countries.1,5,6Several studies have indicated that vitamin B2 deficiency may be widespread in industrialized countries as well, both in the elderly7,8and in young adults.9Dietary deficiency of riboflavin is characterized by lesions on the lips and the angles of the mouth, fissured and magenta-colored tongue, corneal vascularization and normocytic, normochromic anemia.1-4Skin lesions include red scaly, greasy patches on the nose, eyelids, scrotum, and labia and seborrheic dermatitis.1-4These symptoms are a consequence of oxidation stress due to the accumulation of lipid peroxides. Vitamin B2 deficiency leads to reduced activity of the flavin-containing enzymes (glutathione reductase and glutathione peroxidase) which, in turn, allows these peroxidase to express their deleterious effects.Vitamin B2 is involved in the metabolism of folate, vitamin B12, vitamin B6, and other vitamins.10Plasma vitamin B2 is a determinant of plasma homocysteine level, which is associated with cardiovascular disease, pregnancy complications, and cognitive impairment.10Recent studies have suggested that riboflavin may play an important role in the determination of cell fate, which would have implications for growth and development.3Specifically, riboflavin deficiency impairs the normal progression of the cell cycle, probably through effects on the expression of regulatory genes, exerted at both the transcriptional and proteomic level.3No case of riboflavin toxicity in humans has been reported.

Nutrition & Vitamins

Responsible for binding and transporting retinol (vitamin A).

Nutrition & Vitamins

Anemia of chronic disease and iron deficiency anemia, the most common forms of anemia, are differentiated primarily by estimates of iron status. Standard measures of iron status, such as ferritin, total iron-binding capacity, and serum iron are directly affected by chronic disease. In contrast, soluble transferrin receptor (sTfR) is elevated in iron deficiency but is not appreciably affected by chronic disease. sTfR is elevated in subjects with hyperplastic erythropoiesis (eg, hemolytic anemia, beta-thalassemia, polycythemia, etc) and depressed in subjects with hypoplastic erythropoiesis (eg, chronic renal failure, aplastic anemia, or post-transplant anemia). Transferrin receptor (TfR) is the major mediator of iron uptake by cells. TfR is a transmembrane, disulfide-linked dimer of two identical subunits that binds and internalizes diferric transferrin, thereby delivering iron to the cell cytosol. When a cell needs iron, TfR expression is increased to facilitate iron uptake. Since the major use of iron is for hemoglobin synthesis, about 80% of total TfR is on erythroid progenitor cells. Soluble transferrin receptor arises from proteolysis of the intact protein on the cell surface, leading to monomers that can be measured in plasma and serum. Thus, the concentration of sTfR in plasma or serum is an indirect measure of total TfR. The serum level of sTfR reflects either the cellular need for iron or the rate of erythropoiesis. The concentration of sTfR in plasma or serum is elevated in iron deficiency. The concentration of sTfR in plasma or serum is correlated with erythron transferrin uptake, a ferrokinetic measure of erythropoietic activity.

Nutrition & Vitamins

Two types of cholinesterase are found in blood: “true” cholinesterase (acetylcholinesterase) in red cells and “pseudocholinesterase” (acylcholine acylhydrolase) in serum (plasma). Low serum cholinesterase activity may relate to exposure to insecticides or to one of a number of variant genotypes. Dibucaine and fluoride numbers are useful to phenotype such homozygous and heterozygous individuals, who are genetically sensitive to succinylcholine.One patient in 1500 is susceptible to succinyldicholine anesthetic mishap. Evans and Wroe suggest that an enzyme level in serum below 2.5 standard deviations will pick up 90% of sensitive individuals using propionylthiocholine as substrate.4Rather marked inhibition can be found without symptoms.Plasmapheresis has been noted to decrease the level of plasma cholinesterase. Patients with abnormally low cholinesterase activity after transfusion of blood or plasma will experience temporary augmentation of enzyme level.5In estimating the duration of this enhanced activity, measures of plasma cholinesterase half-life have been utilized. The true half-life value has, however, been uncertain. A half-life value determined by measuring the rate of disappearance after intravenous injection of human cholinesterase has provided an average value of 11 days.6A low level of activity of pseudocholinesterase has been demonstrated in cerebrospinal fluid, at about 1/20 to 1/100 the activity present in the corresponding plasma. With clinical conditions characterized by bleeding into the CSF, pseudocholinesterase activity increases to one-fourth to one-half that of plasma.7Patients with a variety of carcinomas have been reported to accumulate an embryonic type of cholinesterase activity in their sera. Such novel cholinesterase activity was found only in the sera of patients undergoing antitumor therapy (eg, chemotherapy or radiation therapy and/or hormone therapy).8Increase in acetylcholinesterase activity, notably, in an acetylcholinesterase:butyrylcholine esterase ratio (histochemical study, not as measured in serum) has provided discriminatory diagnostic value in some cases of Hirschsprung disease.9

Nutrition & Vitamins, Heavy Metals & Toxins

Zinc is an essential element involved in a myriad of enzyme systems including wound healing, immune function, and fetal development. Zinc measurements are used to detect and monitor industrial, dietary, and accidental exposure to zinc. Also, Zinc measurements may be used to evaluate health and monitor response to treatment.

Nutrition & Vitamins

This quantitative test, performed with a 24-hour urine specimen, may help screen for hypercalciuria, one of the established risk factors for kidney stone formation [1-3]. This test may also help assess metabolic disorders of calcium metabolism, such as hyperparathyroidism, bone disease, and idiopathic hypercalciuria. In general, 24-hour urine specimens are preferred to random urine specimens when measuring calcium for diagnostic evaluation of hypercalciuria [1].Calcium is essential for bone formation and nerve, muscle, and heart functions. Calcium metabolism is jointly regulated by parathyroid hormone and vitamin D metabolites. Urinary calcium excretion is the major route of calcium elimination and reflects kidney tubular filtration and reabsorption of calcium in addition to dietary intake, intestinal absorption, and bone resorption [2]. Creatinine excretion is useful in determining whether 24-hour urine specimens for calcium have been completely and accurately collected because daily urine excretion of creatinine generally shows minimal fluctuation [2].Urinary calcium levels may be elevated in patients with idiopathic hypercalciuria, chronic kidney disease, hyperparathyroidism, vitamin D intoxication, Paget disease of bone, sarcoidosis, or conditions that infiltrate and destroy bones (eg, multiple myeloma and a variety of metastatic cancers) [2,3]. Urinary calcium levels may be decreased in patients with hypoparathyroidism, vitamin D deficiency rickets, osteomalacia, or familial hypocalciuric hypercalcemia [2,3].A calcium/creatinine clearance ratio, calculated from 24-hour urinary calcium and creatinine concentrations and total serum calcium and creatinine concentrations may help differentiate primary hyperparathyroidism (PHPT) from familial hypocalciuric hypercalcemia (FHH) [4].Note that use of calcium supplements and loop diuretics may cause increased urinary calcium levels; thiazide diuretics may cause decreased urinary calcium levels [3].The results of this test should be interpreted in the context of pertinent clinical and family history and physical examination findings.References1. Williams JC Jr, et al.Urolithiasis. 2021;49(1):1-16.2. Rifai N, et al. eds.Tietz Textbook of Laboratory Medicine. 7th ed. Elservier Inc; 20223. MedlinePlus [Internet]. Calcium-urine. Accessed September 1, 2022.https://medlineplus.gov/ency/article/003603.htm4. Arshad MF, et al.Postgrad Med J. 2021;97(1151):577-582.

Nutrition & Vitamins, Diabetes & Blood Sugar

Offered as part of multiple lab tests

Nutrition & Vitamins

Osteocalcin, or bone Gla protein (BGP), is the major noncollagenous protein of bone matrix. It has a molecular weight of approximately 5.8 kilodaltons and consists of 49 amino acids, including three residues of γ-carboxyglutamic acid. Osteocalcin is synthesized in bone by osteoblasts. After production, it is partly incorporated into the bone matrix and partly delivered to the circulatory system. The precise physiological function of osteocalcin is still unclear. A large number of studies have shown that the circulating level of osteocalcin reflects the rate of bone formation.Determination of serum osteocalcin has proven to be valuable as an aid in identifying women at risk of developing osteoporosis, for monitoring bone metabolism during perimenopause and postmenopause, and during antiresorptive therapy.

Nutrition & Vitamins

Offered as part of multiple lab tests

Nutrition & Vitamins, Blood Disorders

B12 is essential for certain enzymatic reactions that are required for numerous physiologic functions including erythropoiesis and myelin synthesis.1,2Impaired DNA synthesis caused by B12 deficiency impacts nuclear maturation of rapidly dividing cells. This affects hematopoiesis and results in the presence of immature and ineffective red cells that are larger than normal (megaloblasts) in a context of severe anemia and pancytopenia. This megaloblastic anemia is characterized by the hypersegmented neutrophils that can be seen on peripheral smears and giant bands in bone marrow. Other rapidly dividing cells of the small-bowel epithelium can be affected resulting in malabsorption and diarrhea.3Glossitis is a frequent hallmark of megaloblastic anemia, with the patient experiencing a painful, smooth, red tongue. Ineffective erythropoiesis and associated increased red cell turnover can result in elevation in bilirubin levels, manifesting as jaundice.3B12 deficiency can also produce neurological manifestations including sensory and motor disturbances (symmetric paresthesias, numbness and gait problems), ataxia, cognitive decline leading to dementia and psychiatric disorders. These neurological symptoms often predominate and can frequently occur in the absence of hematological complications.3,7In fact, the majority of patients with suspected B12 deficiency do not have anemia.5-8Emerging evidence indicates that low (though not necessarily deficient) B12 is associated with increased risk of various chronic diseases of ageing including cognitive dysfunction, cardiovascular disease and osteoporosis.5,6Dietary vitamin B12 is normally bound to proteins in food and requires release by gastric acid and pepsin in the stomach.7In the small intestine, vitamin B12 binds to intrinsic factor (IF) produced by gastric parietal cells. In the ileum, the B12-IF complex binds to specific receptors, which facilitates absorption into the blood. Large amounts of absorbed vitamin B12 are stored in the liver such that any reduction in vitamin B12 intake/absorption may take many years to manifest clinically.8Low B12 status, especially in older adults, is rarely attributable to dietary insufficiency9and is more typically the result of malabsorption related to atrophic gastritis, inflammatory bowel disease or use of proton pump inhibitors or other gastric acid suppressant drugs.2,6,7,10-13The diagnosis of vitamin B12 deficiency requires consideration of both the clinical state of the patient and the results of laboratory tests. Screening average-risk adults for vitamin B12 deficiency is not recommended.2However, testing should be considered in patients with risk factors and/or clinical blood count and serum vitamin B12 level.2,5,7,14,15The World Health Organization16and the British Committee for Standards in Haematology14suggested using 200 pg/mL as a cut-off to define B12 deficiency. In practice, detectable disturbances in metabolic networks consistent with possible deficiency occur at B12 levels as high as 400 pg/mL.17A significant number of B12-deficient patients may be overlooked when serum B12 measurement is used in isolation.5,17Further investigation using a second-line test can be useful for serum B12 results that fall within the indeterminate range. The enzyme, methylmalonyl-CoA mutase requires vitamin B12 as a cofactor for the conversion of methylmalonyl-CoA to succinyl-CoA.5In vitamin B12 depletion, reduced activity of this enzyme leads to an accumulation of methylmalonyl-CoA which is, in turn, hydrolyzed to methylmalonic acid. Measurement of serum methylmalonic acid provides biochemical evidence of metabolic abnormalities consistent with B12 insufficiency.2,5,7,10,14,18,19In the United States and the United Kingdom, the prevalence of vitamin B12 deficiency has been estimated to be approximately 6% of persons younger than 60 years, and nearly 20% in those older than 60 years.10B12 status in the United States has been assessed in the National Health and Nutrition Examination Survey (NHANES).20Using NHANES data from 1999 to 2004, the prevalence of B12 status defined as low was estimated to be 2.9%, 10.6% or 25.7% based on serum B12 cut-off values of 200, 300 and 400 pg/mL, respectively.20Using these cut-off values, the prevalence of low B12 status increased with age from young adults (19-39 years of age) to older adults (greater than or equal to 60 years of age), and was generally higher in women than than in men (prevalence of 3.3% versus 2.4% with a serum B12 level of <200 pg/mL, respectively).20Using increased levels of MMA as a functional indicator of B12 status, the prevalence of low B12 status was 2.3% or 5.8% based on cut-off values of >376 and >271 nmol/L, respectively.20The prevalence of increased levels of MMA increased with age and was not different between men and women.20Notably, only 50-75% of participants in NHANES with low levels of serum B12 had increased levels of MMA.20It should also be noted that modest increases occur with renal failure.7Pernicious Anemia (PA) caused by autoimmune destruction of gastric parietal cells and atrophy of the gastric mucosa is the most common cause of vitamin B12 deficiency.3,6,7,21Asymptomatic autoimmune gastritis, a chronic inflammatory disease of the gastric mucosa, precedes the onset of mucosal atrophy by 10-20 years.22With disease progression, an increasing number of the parietal cells that produce hydrochloric acid and intrinisic factor are destroyed.22This may present initially as iron deficiency anemia due to loss of gastric acid, which is required for iron absorption.1,23Ultimately, diminished production of intrinsic factor together with development of neutralizing antibody against intrinsic factor itself leads to B12 malabsorption.2,3,10,24The autoimmune nature of PA is reflected by the presence of autoantibodies against the parietal cell proton pump protein (H/K ATPase) and to intrinsic factor.3,20,24,25This condition frequently coexists with other autoimmune disorders including Hashimoto's thyroiditis and type 1 diabetes mellitus.3,24,29Parietal Cell Antibodies (PCA) are present at a high frequency in PA (80%-90%), especially in early stages of the disease and are considered a predictive marker of subsequent gastric mucosa atrophy and its hematologic manifestations.3,24In the later stages of the disease, the incidence of PCA decreases due to the progression of autoimmune gastritis and a loss of gastric parietal cell mass, as a result of the decrease in antigenic rate.26PCA can precede the clinical symptoms of the gastric disease by several years.3PCA are found in 90% of patients with PA, but have low specificity and are seen in various autoimmune disorders.1Intrinsic Factor Antibodies (IFA) are less sensitive, but are considered highly specific for PA.3Studies have reported positivity for IFA in 40%-60% of patients with PA, which rises to 60%-80% with increasing duration of disease.3,27The combined assessment of both PCA and IFA increases diagnostic performance, with 73% sensitivity and 100% specificity.28Diminished acid secretion caused by gastric atrophy resulting from autoimmune disease or some other etiology elevates secretion of gastrin. Elevated gastrin levels can support the diagnosis of PA.24,29Hypergastrinaemia arising from loss gastric parietal cells drives development of antral enterochromaffin cell hyperplasia that can further develop into neoplasia and carcinoid syndrome.1,3,24,30,31

Nutrition & Vitamins

Pantothenic acid is a water-soluble vitamin that is also referred to as vitamin B5.1-3Pantothenic acid and its derivatives are found in all cells as an integral part of the acylation carriers, coenzyme A (CoA) and acyl carrier protein.1-3CoA is required for the synthesis of essential fats, cholesterol, and steroid hormones, as well as acetylcholine and melatonin.1CoA is integral to the Krebs' cycle and the catabolism of fatty acids and proteins.1It is also used in the manufacture of heme, a component of hemoglobin, and in the catabolism of a number of drugs by the liver.1Protein acetylation is also thought to play a roll in cell division, DNA replication, and in cell signaling.1In recent times, fulminate vitamin B5deficiency has only been observed in individuals who have been fed semisynthetic diets devoid of pantothenic acid or individuals who have ingested a metabolic antagonist to the vitamin, ω-methyl-pantothenic acid.2In these cases, symptoms included irritability, fatigue, sleep disturbances, nausea, vomiting, abdominal cramps, numbness, paresthesias, muscle cramps, a staggering gait, hypoglycemia, and an increased sensitivity to insulin.2,3Historically, severe vitamin B5deficiency was associated with the "burning feet" syndrome that affected prisoners of war in the Philippines, Burma, and Japan during World War II.2Vitamin B5supplements often contain pantothenol, a relatively stable alcohol derivative of pantothenic acid, which is rapidly converted to pantothenic acid after ingestion.1The calcium salt of pantothenic acid is also available in supplements.1Pantethine, a dimeric form of pantothenic acid, is used as a cholesterol-lowering agent in Europe and Japan and is available in the US as a dietary supplement that is converted to vitamin B5after ingestion.1

Nutrition & Vitamins

Nicotinic acid occurs naturally in plants and animals and is also added to many foods as a vitamin supplement.

Nutrition & Vitamins

Vitamin B5 (Pantothenic Acid) is a component of coenzyme A and phosphopantetheine both of which are involved in fatty acid metabolism. It is essential to almost all forms of life and is widely distributed in food.

Nutrition & Vitamins

Celiac disease is a gluten enteropathy occurring in both children and adults. The disease is probably underdiagnosed in that it may affect as much as 1% of the population in the US. The condition is characterized by a sensitivity to gluten (found in wheat, barley, and rye) that causes inflammation and atrophy of the villi of the small intestine, malabsorption, etc. This sensitivity to gluten may also be seen in dermatitis herpetiformis. Strict avoidance of gluten in the diet will control disease activity, and antibodies to serum markers will disappear with time.

Nutrition & Vitamins

Niacin (nicotinic acid) is a water-soluble vitamin that is also referred to as vitamin B3.1,2Nicotinamide (nicotinic acid amide) is the derivative of niacin that is incorporated into the coenzymes nicotinamide adenine dinucleotide (NAD) and nicotinamide adenine dinucleotide phosphate (NADP).1-3The nicotinamide moiety of NAD and NADP serves as an electron acceptor or donor in biological oxidation-reduction (redox) reactions catalyzed by several hundred different enzymes. NAD serves as the cofactor for enzymes that break down (catabolize) carbohydrates, fats, proteins, and alcohol while NADP supports biosynthetic (anabolic) reactions, including the synthesis of all macromolecules, such as fatty acids and cholesterol.1,2Nicotinamide has also been shown to serve as a cofactor in adenosine diphosphate (ADP)-ribose transfer reactions that play an integral part in deoxyribonucleic acid (DNA) repair calcium mobilization.3,4Studies of cultured cells and animal models suggest that ADP-ribose polymer-mediated DNA repair and cyclic ADP-ribose-mediated cell-signaling pathway may play a role in cancer prevention.3,4Both nicotinic acid and nicotinamide are absorbed from the normal diet. Nicotinamide is the form of vitamin B3that is commonly found in nutritional supplements and used to fortify foods.1,5Nicotinic acid is available both over the counter and with a prescription as a cholesterol-lowering agent.6-8Niacin deficiency can result from inadequate dietary intake of niacin and/or the amino acid tryptophan. Tryptophan, obtained from the breakdown of dietary protein, can be converted to nicotinamide by liver enzymes that require vitamin B6, riboflavin, and iron. Deficiencies of these constituents can contribute to the development of niacin deficiency.1,2Hartnup's disease, a hereditary disorder that reduces tryptophan absorption, can lead to niacin deficiency.1Carcinoid syndrome diverts tryptophan to the increased production of serotonin and can reduce the production of nicotinamide.1Prolonged treatment with isoniazid has also been associated with niacin deficiency.1Niacin deficiency can affect the skin, digestive system, and the nervous system.1,2Severe niacin deficiency, referred to as pellagra, has been associated with the "four Ds": dermatitis, diarrhea, dementia, and ultimately death.2Pellagra dermatitis is characterized by a thick, scaly, darkly pigmented rash that develops symmetrically in areas exposed to sunlight.2Digestive system symptoms include vomiting, constipation or diarrhea, and a bright red tongue.1,2Pellagra can also cause neurologic symptoms, including apathy, fatigue, depression, headache, disorientation, and memory loss.1,2

Nutrition & Vitamins

The biological function of vitamin D is to maintain normal levels of calcium and phosphorus absorption. 25-Hydroxy vitamin D is the storage form of vitamin D. Vitamin D assists in maintaining bone health by facilitating calcium absorption. Vitamin D deficiency can also cause osteomalacia, which frequently affects elderly patients. Vitamin D from sunshine on the skin or from dietary intake is converted predominantly by the liver into 25-hydroxy vitamin D, which has a long half-life and is stored in the adipose tissue. The metabolically active form of vitamin D, 1,25-di-hydroxy vitamin D, which has a short life, is then synthesized in the kidney as needed from circulating 25-hydroxy vitamin D. The reference interval of greater than 30 ng/mL is a target value established by the Endocrine Society.2

Liver & Kidney Health, Nutrition & Vitamins

Offered as part of multiple lab tests

Nutrition & Vitamins

Vitamin B5 (Pantothenic Acid) is a component of coenzyme A and phosphopantetheine both of which are involved in fatty acid metabolism. It is essential to almost all forms of life and is widely distributed in food.

Genetic Testing, Nutrition & Vitamins

Offered as part of multiple lab tests

Nutrition & Vitamins

Offered as part of multiple lab tests

Genetic Testing, Nutrition & Vitamins

Offered as part of multiple lab tests

Genetic Testing, Nutrition & Vitamins

Offered as part of multiple lab tests

Nutrition & Vitamins

Hepatitis D virus (HDV) infection requires the surface antigen from HBV and may occur as an acute infection with HBV or as a superinfection of a chronic HBV infection. HDV should be considered in any individual who tests positive for the HBV surface antigen (HBsAg). The presence of HDV RNA in the serum reflects viral replication in the liver. HDV-HBV co-infection is considered the most severe form of chronic viral hepatitis due to more rapid progression towards liver-related death and hepatocellular carcinoma. HDV RNA, quantitative real-time PCR can assist with diagnosis of HDV infection as well as monitoring of treatment.

Nutrition & Vitamins

Antibodies to antigens in the ABO and Rh systems are the most common causes of hemolytic disease of the newborn.

Nutrition & Vitamins

Some isolates ofStaphylococcusspeciesStreptococcus Pneumoniaeand beta-hemolyticStreptococcihave been shown to have inducible resistance to clindamycin. Treatment of a patient with clindamycin for an organism that has inducible clindamycin resistance (D Test positive) may result in treatment failure.

Nutrition & Vitamins

Hepatitis D Virus (HDV) is an RNA virus whose transmission is dependent on associated hepatitis B viral infection.

Nutrition & Vitamins

While measurements of 25(OH)D provide a good index of circulating Vitamin D activity in patients not suffering from renal disease, for infants less than 3 years of age it is important to remove circulating levels of the inactive c3-epimer of Vitamin D from the sample so that total Vitamin D levels are not falsely elevated. Falsely elevated results could erroneously make the child appear to be within normal limits and result in potential under-treatment. Levels of c3-epimer in older children and adults are usually negligible and do not cause falsely elevated Vitamin D results.This assay employs advanced liquid chromatography - tandem mass spectrometry, which enables the chromatographic separation of the c3-epimer from 25-OH Vitamin D, thereby allowing accurate measurement in the presence of c3-epimer. While this assay will produce accurate Vitamin D results on patients of any age, it is specifically indicated for infants less than 3 years of age.

Nutrition & Vitamins

Amino Acid analysis is necessary for the diagnosis of a variety of inborn errors of metabolism. These include, but are not limited to, phenylketonuria, tyrosinemia, citrullinemia, non-ketotic hyperglycinemia, maple syrup urine disease, and homocystinuria. The assay is also key for the continued monitoring of treatment plans for these disorders and useful for assessing nutritional status of patients. Our methodology is highly accurate at very low levels as well as at elevated levels.

Nutrition & Vitamins

Vitamin D originating from dietary and endogenous sources is converted to 25-hydroxyvitamin D in the liver, and subsequently to 1, 25-dihydroxyvitamin D in the kidney. Measurement of both the 1, 25-Dihydroxy and 25-Hydroxy forms provide insights into a variety of medical conditions such Vitamin D status in renal failure, differential diagnosis of primary, secondary and tertiary hyperparathyroidism. Differential diagnosis of hypercalcemia and type I and II inherited rickets.

Nutrition & Vitamins, General Health & Wellness

Test is used to determine vitamin B6 deficiency or overdosage, for monitoring treatment, and to evaluate wellness and health.

Nutrition & Vitamins, General Health & Wellness

Vitamin B1 is required for branched-chain amino acid and carbohydrate metabolism. Vitamin B1 deficiency is most often due to alcoholism or chronic illness. In the early stage, patients with vitamin B1 deficiency exhibit anorexia, irritability, apathy, and generalized weakness. Prolonged deficiency causes beriberi.

Nutrition & Vitamins

This panel of LC/MS/MS assays measures Beta-Amyloid 42/40 Ratio and ApoE Isoform and Total ApoE in CSF. Test results are further analyzed by an algorithm that calculates a risk assessment score. Based on this score, patients are categorized as low, intermediate, or high risk of having AD.

Heavy Metals & Toxins, Nutrition & Vitamins

Offered as part of multiple lab tests

Nutrition & Vitamins

Biotin, vitamin B7, or vitamin H, is a water soluble vitamin. The vitamin plays a role in the transferring of carbon dioxide in the metabolism of fat, carbohydrate and protein by functioning as an enzyme cofactor. It is involved in multiple biochemical reactions including niacin metabolism, amino acid degradation, and the formation of purine, which is an integral part of nucleic acids. It interacts with histone by the action of biotinyl-transferase. Sometimes the vitamin is used in weight reduction programs. It may be prescribed as a supplement for diabetic patients due to its role in carbohydrate metabolism. Biotin is commonly found in vitamin B complex and many food sources, such as milk, yeast, egg yolk, cereal, and mushrooms. The reference daily intake [RDI of 101.9(c) (8) (IV)] for vitamin B7 is 300 micrograms. Deficiency in the vitamin may result in seborrheic dermatitis, alopecia, myalgia, hyperesthesia, and conjunctivitis. Disorders of biotin metabolism can be acquired or congenital. Biotinidase and holocarboxylase synthethase deficiency are the two better known forms of disorders. The lack of biotin-dependent pyruvate carboxylase, propionyl-CoA carboxylase, methylcrotonyl-CoA carboxylase, and acetyl-CoA carboxylase can lead to the life-threatening disorder of multiple carboxylase deficiency. Treatment involves a daily dose of approximately 10 mg biotin/day. Irreversible mental or neurological abnormalities may result from delayed clinical intervention.

Nutrition & Vitamins, Bone Health

The biological function of vitamin D is to maintain normal levels of calcium and phosphorus absorption. 25-Hydroxy vitamin D is the storage form of vitamin D. Vitamin D assists in maintaining bone health by facilitating calcium absorption. Vitamin D deficiency can also cause osteomalacia, which frequently affects elderly patients. Vitamin D from sunshine on the skin or from dietary intake is converted predominantly by the liver into 25-hydroxy vitamin D, which has a long half-life and is stored in the adipose tissue. The metabolically active form of vitamin D, 1,25-di-hydroxy vitamin D, which has a short life, is then synthesized in the kidney as needed from circulating 25-hydroxy vitamin D. The reference interval of greater than 30 ng/mL is a target value established by the Endocrine Society.1

Nutrition & Vitamins

Useful in autoimmune disorders involving parathyroid gland resulting in the production of anti-PTH & hypo-parathyroidism.

Nutrition & Vitamins

Celiac disease is a gluten enteropathy occurring in both children and adults. The disease is probably underdiagnosed in that it may affect as much as 1% of the population in the US. The condition is characterized by a sensitivity to gluten (found in wheat, barley, and rye) that causes inflammation and atrophy of the villi of the small intestine, malabsorption, etc. This sensitivity to gluten may also be seen in dermatitis herpetiformis. Strict avoidance of gluten in the diet will control disease activity, and antibodies to serum markers will disappear with time.

Genetic Testing, Nutrition & Vitamins

Offered as part of multiple lab tests

Nutrition & Vitamins

This quantitative oxalic acid test, performed with a random urine specimen, may help screen for hyperoxaluria, determine the cause of kidney stones, and assess kidney function in adults [1]. However, 24-hour urine specimens are generally preferred to random specimens when measuring oxalic acid for diagnostic evaluation and monitoring of hyperoxaluria [1,2].Oxalic acid is an organic compound that naturally exists in many food sources. Because humans cannot metabolize oxalic acid, it must be excreted in urine as oxalate (the ionic form of oxalic acid). Excessive excretion of oxalates is called hyperoxaluria and can be attributed to primary or secondary causes. Primary hyperoxaluria (PH) is a rare condition resulting from enzymatic defects and can lead to chronic kidney disease, which may progress to kidney failure. Secondary hyperoxaluria can be caused by fat malabsorption, which may be due to inflammatory bowel disease, extensive resection of the small bowel, or excessive ingestion of substances that increase serum oxalates [3].PH is associated with significant morbidity and mortality, including end-stage kidney disease [1].Early diagnosis is associated with better outcomes, but more than 40% of PH diagnoses are delayed [1]. Screening for PH may be considered for adults with recurrent calcium oxalate stones or family history of stone disease [1].Urinary oxalic acid measurements may be inaccurate when estimated glomerular filtration rate declines [1]. Therefore, in patients with chronic kidney disease, plasma oxalate may be measured to help support the diagnosis of PH [1].Results of this test should be interpreted in the context of pertinent clinical and family history and physical examination findings.⁠⁠⁠⁠⁠⁠⁠References1. Bhasin B, et al.World J Nephrol. 2015;4(2):235-244.2. Williams JC Jr, et al.Urolithiasis. 2021;49(1):1-16.3. Shchelochkov O, et al. Defects in metabolism of amino acids. In: Kliegman R, et al.Nelson Textbook of Pediatrics. 21st ed. Elsevier; 2019:720-722.

Nutrition & Vitamins

Dipstick urinalysis is important in accessing the chemical constituents in the urine and the relationship to various disease states. Microscopic examination helps to detect the presence of abnormal urine cells and formed elements. Culture may identify the organism(s) causing infection.

Nutrition & Vitamins

This test is intended for the qualitative detection of Zika virus in serum and urine from individuals who meet the Centers for Disease Control and Prevention (CDC) clinical and epidemiological criteria for Zika virus testing. Zika viruses are primarily transmitted byAedes aegyptiandAedes albopictusmosquitos [1].Most individuals with a Zika virus infection are asymptomatic. Individuals with symptomatic infections may experience fever, rash, and muscle/joint pain [2].Per the 2019 CDC guidelines, testing is recommended only for symptomatic pregnant women with a history of living in or traveling to a geographic area at risk for Zika. For current testing guidelines, seehttps://www.cdc.gov/zika/hc-providers/testing-guidance.htmlFor individuals meeting the CDC criteria, concurrent testing of serum and urine is recommended as soon as possible after symptom onset. Zika infection shares clinical and epidemiological features with other arbovirus infections such as Dengue and Chikungunya. For CDC guidelines on testing concurrently for Zika and Dengue, seehttps://www.cdc.gov/dengue/healthcare-providers/testing/testing-guidance.html1. Subcommittee on Laboratory Practices, ASM, and Public Relations Committee, Pan American Society for Clinical Virology (PASCV). Zika Virus: An Update on the Disease and Guidance for Laboratory Testing. September 2022. Accessed May 9, 2023.https://asm.org/Guideline/Zika-virus-An-update-on-the-disease-and-guidance-f2. Sharp TM, et al. MMWR Recomm Rep. 2019 Jun 14;68(1):1-10.

Nutrition & Vitamins

Any bacterial colony count may be significant.

Nutrition & Vitamins

Urinary vanillylmandelic acid (VMA) concentration is useful in the biochemical diagnosis and monitoring of neuroblastomas [1].Neuroblastomas occur predominantly in children and are the most common malignancy in those under 1 year old. Neuroblastomas are catecholamine-metabolizing tumors with limited ability to store and secrete catecholamines. Thus, catecholamine metabolites-including VMA and homovanillic acid (HVA)-are more reliable than catecholamines as biochemical markers for neuroblastomas [1]. VMA and HVA levels, usually measured simultaneously, can be elevated in neuroblastomas as well as other catecholamine-secreting tumors, such as pheochromocytoma [1]. In patients with familial dysautonomia (Riley-Day syndrome), a neurological disorder found mainly in individuals of Ashkenazi Jewish descent, VMA levels are generally elevated while HAV levels may be normal or decreased [2].Urinary VMA and HVA levels may have limited accuracy for diagnosis of neuroblastomas with high-risk metastatic biology [1]. Therefore, dopamine levels in urine or serum have been proposed as an additional marker for diagnosis and monitoring of neuroblastomas [3].The results of this test should be interpreted in the context of pertinent clinical and family history and physical examination findings.References1. Eisenhofer G. Monoamine-producing tumors. In: Rifai R, et al. eds.Tietz Textbook of Laboratory Medicine. 7th ed. Elsevier Inc; 2022.2. Axelrod FB. Familial dysautonomia.Muscle Nerve. 2004;29(3):352-363.3. Brodeur GM, et al.J Clin Oncol. 1993;11(8):1466-1477.

Nutrition & Vitamins

Amino acid analysis is necessary for the diagnosis of a variety of inborn errors of metabolism. These include, but are not limited to, phenylketonuria, tyrosimemia, citrullinemia, non-ketotic hyperglycinemia, maple syrup urine disease, and homocystinuria. The assay is also key for the continued monitoring of treatment plans for these disorders and useful for assessing nutritional status of patients. Our methodology is highly accurate at very low levels as well as at elevated levels.

Nutrition & Vitamins

Acylglycines are an important class of metabolites that are used in the diagnosis of several organic acidurias and mitochondrial fatty acid oxidation disorders.This test is intended for the diagnosis and monitoring of several organic acidemias and fatty acid disorders affecting multiple metabolic pathways.Disorders diagnosed by Acylglycines assay:Isovaleric acidemia3-Methylcrotonyl-Co-A-carboxylase deficiencyShort-chain acyl-CoA dehydrogenase(SCAD) deficiencyEthylmalonic EncephalopathyPropionic acidemiaGlutaric aciduria type-1, 2 and 3Medium-chain acyl-CoA dehydrogenase(MCAD)Beta-ketothiolase deficiency17-Beta-hydroxysteroid dehydrogenase deficiencyIsobutyryl-CoA dehydrogenase deficiencyShort/branched-chain acyl-CoA dehydrogenase deficiency (SBCADD)The test will also allow physicians to determine dietary compliance or the effectiveness of dietary/cofactor therapy for their patients. It can also be used, alone or in conjunction with other tests, to confirm the findings of a positive expanded newborn screen.

Nutrition & Vitamins

Ehrlichia chaffeensisDNA PCR is a highly sensitive method to detect the presence ofehrlichia chaffeensisDNA in clinical specimens.The diagnosis ofehrlichia chaffeensisinfection should not rely solely upon the result of PCR assay. A positive result should be considered in conjunction with clinical presentation and additional established clinical tests. Moreover, this assay cannot differentiate between viable and nonviable organisms. A negative PCR result indicates the absence ofehrlichia chaffeensisDNA at detectable levels in the sample tested and does not exclude the diagnosis of disease.

Nutrition & Vitamins

Entamoeba histolyticaare intestinal parasites that infect a half billion people worldwide annually. Of those infected, most are infected with the non-pathogenicE. dispar, which has not been associated with disease. It is estimated that approximately 10% of the half billion people infected each year are infected with the pathogenicE. histolytica. These individuals become symptomatic and develop colitis and liver abscesses.

Nutrition & Vitamins

This test is intended for the diagnosis and monitoring of inherited disorders affecting multiple metabolic pathways.Organic acidurias are inherited disorders resulting from a deficient enzyme or transport protein. Although most are autosomal recessive disorders, several are X-linked. The more than 60 described organic acidurias affect many metabolic pathways including amino acid metabolism, lipid metabolism, purine and pyrimidine metabolism, the urea cycle, the Krebs cycle and fatty acid oxidation. These disorders are characterized by a wide variety of symptoms such as lethargy, coma, hypotonia, seizures, ataxia, vomiting, failure to thrive, developmental delay, liver disease, neutropenia, thrombocytopenia, osteomalacia and osteoporosis. Severity of presentation is highly variable as is age of onset, and patients may not present with the most characteristic features. Laboratory results commonly indicate metabolic acidosis, increased anion gap, hyperammonemia, hypoglycemia, lactic acidemia, ketosis, or abnormal lipid patterns. Treatment may be based on dietary restrictions and/or supplementation with cofactors (e.g., riboflavin or cobalamin) or conjugating agents (e.g., carnitine or sodium benzoate); however, there is no effective therapy for some of the disorders.Elevation of one or more organic acids is diagnostic for an organic aciduria; however, elevations should be interpreted in context with clinical findings and/or additional test results. See additional information for a table of selected organic acidurias and associated organic acid elevations. Since many organic acidurias are episodic, the diagnostic efficacy is maximized when the patient is expressing symptoms at the time of specimen collection.The test will be capable of diagnosing over 30 inherited metabolic defects, and will also allow physicians to determine dietary compliance or the effectiveness of dietary/cofactor therapy for their patients. It can also be used, alone or in conjunction with other tests, to confirm the findings of a positive expanded newborn screen.

Nutrition & Vitamins

The determination of proteinuria is a well established laboratory procedure for the evaluation of renal disease (glomerular, tubular and overflow proteinuria), urinary tract inflammation, orthostatic proteinuria and preeclampsia (a potential complication of pregnancy). A more rapid clinical assessment of proteinuria using a 12-hour specimen enables a faster diagnosis with subsequent intervention in several of the clinical conditions cited above.

Nutrition & Vitamins

Immunofixation of urine is useful in evaluation of monoclonal free light chains and other monoclonal gammopathies seen in light chain disease, multiple myeloma, Waldenstrom's macroglobulinemia, amyloidosis, and other lymphoproliferative disorders. Increased polyclonal free light chains in urine may be seen in glomerular leak syndromes and in infection or inflammation.

Nutrition & Vitamins

Proteinuria is characteristic of renal disease and concentrations may be increased with diabetes, hypertension, nephritic syndrome, and drug nephrotoxicity.

Nutrition & Vitamins

This test is intended for the diagnosis and monitoring of inherited disorders affecting multiple metabolic pathways.Organic acidurias are inherited disorders resulting from a deficient enzyme or transport protein. Although most are autosomal recessive disorders, several are X-linked. The more than 60 described organic acidurias affect many metabolic pathways including amino acid metabolism, lipid metabolism, purine and pyrimidine metabolism, the urea cycle, the Krebs cycle and fatty acid oxidation. These disorders are characterized by a wide variety of symptoms such as lethargy, coma, hypotonia, seizures, ataxia, vomiting, failure to thrive, developmental delay, liver disease, neutropenia, thrombocytopenia, osteomalacia and osteoporosis. Severity of presentation is highly variable as is age of onset, and patients may not present with the most characteristic features. Laboratory results commonly indicate metabolic acidosis, increased anion gap, hyperammonemia, hypoglycemia, lactic acidemia, ketosis, or abnormal lipid patterns. Treatment may be based on dietary restrictions and/or supplementation with cofactors (e.g., riboflavin or cobalamin) or conjugating agents (e.g., carnitine or sodium benzoate); however, there is no effective therapy for some of the disorders.Elevation of one or more organic acids is diagnostic for an organic aciduria; however, elevations should be interpreted in context with clinical findings and/or additional test results. See additional information for a table of selected organic acidurias and associated organic acid elevations. Since many organic acidurias are episodic, the diagnostic efficacy is maximized when the patient is expressing symptoms at the time of specimen collection.The test will be capable of diagnosing over 30 inherited metabolic defects, and will also allow physicians to determine dietary compliance or the effectiveness of dietary/cofactor therapy for their patients. It can also be used, alone or in conjunction with other tests, to confirm the findings of a positive expanded newborn screen.

Nutrition & Vitamins

Urinary excretion of potassium is increased in primary aldosteronism. It is often increased in dehydration and in salicylate toxicity. Decreased levels are seen in malabsorption.

Nutrition & Vitamins

This test is used to determine the presence of BK Virus DNA in patients' specimens. Detection of the virus in these specimens may be indicative of an active infection, as PCR detects the presence of the virus, and not the host's reaction to the virus. Polyomavirus BK DNA detection in urine is associated with an increased risk of graft rejection in renal transplant recipients.

Nutrition & Vitamins

This quantitative test, performed with a random urine specimen, may help screen for hypercalciuria, one of the established risk factors for kidney stone formation [1-3]. This test may also help assess metabolic disorders of calcium metabolism, such as hyperparathyroidism, bone disease, and idiopathic hypercalciuria. In general, 24-hour urine specimens are preferred to random urine specimens when measuring calcium for diagnostic evaluation of hypercalciuria [1].Calcium is essential for bone formation and nerve, muscle, and heart functions. Calcium metabolism is jointly regulated by parathyroid hormone and vitamin D metabolites. Urinary calcium excretion is the major route of calcium elimination and reflects kidney tubular filtration and reabsorption of calcium in addition to dietary intake, intestinal absorption, and bone resorption [2].Urinary calcium levels may be elevated in patients with idiopathic hypercalciuria, chronic kidney disease, hyperparathyroidism, vitamin D intoxication, Paget disease of bone, sarcoidosis, or conditions that infiltrate and destroy bones (eg, multiple myeloma and a variety of metastatic cancers) [2,3]. Urinary calcium levels may be decreased in patients with hypoparathyroidism, vitamin D deficiency rickets, osteomalacia, or familial hypocalciuric hypercalcemia [2,3].Note that use of calcium supplements and loop diuretics may cause increased urinary calcium levels; thiazide diuretics may cause decreased urinary calcium levels [3].This test is also available with creatinine (Calcium, Random Urine with Creatinine), which includes calcium to creatinine ratio to adjust for the concentration differences in random urine specimens.The results of this test should be interpreted in the context of pertinent clinical and family history and physical examination findings.References1. Williams JC Jr, et al.Urolithiasis. 2021;49(1):1-16.2. Rifai N, et al. eds.Tietz Textbook of Laboratory Medicine. 7th ed. Elservier Inc; 20223. MedlinePlus [Internet]. Calcium-urine. Accessed September 1, 2022.https://medlineplus.gov/ency/article/003603.htm

Nutrition & Vitamins

Certain dietary conditions can produce acid or alkaline urines, which can be useful in treatment of some calculi.

Nutrition & Vitamins

This culture is designed to quantitate the growth of significant bacteria when collected by the Clean Catch Guidelines or from indwelling catheters. Quantitative culturing of urine is an established tool to differentiate significant bacteriuria from contamination introduced during voiding. This test has a reference range of less than 1,000 bacteria per mL. More than 95% of Urinary Tract Infections (UTI) are attributed to a single organism. Infecting organisms are usually present at greater that 100,000 per mL, but a lower density may be clinically important. In cases of UTI where more than one organism is present, the predominant organism is usually significant and others are probably urethral or collection contaminants. When multiple organisms are isolated from patients with indwelling catheters, UTI is doubtful and colonization likely.This order code includes full susceptibility testing for isolates of Group B Streptococcus.

Nutrition & Vitamins

JC Polyoma Virus is the cause of progressive multifocal leukoencephalopathy (PML), a demyelinating neurologic disease of immunosuppressed patients. This test detects JC Polyoma Virus DNA in urine.Detection of the virus in specimens from AIDS and other severely immune compromised patients may indicate disease. Serum antibodies are not helpful in diagnosing PML as antibodies are common in the general population. JCV can also be detected in the urine of 3% of pregnant women, but is not associated with proven disease.

Nutrition & Vitamins

Vanillylmandelic Acid (VMA) is the major urinary project resulting from the metabolic degradation of catecholamine, norepinephrine and epinephrine. Elevated concentrations of VMA are commonly found in cases of catecholamine secreting tumors such as pheochromocytoma, neuroblastoma, and ganglioneuroma.Drugs which can interfere with testing due to physiologic response: clonidine, L-dopa, methocarbamol, monoamine oxidase inhibitors, reserpine, salicylates.

Nutrition & Vitamins

Monitor response to antiresorptive therapy in postmenopausal women and individuals with osteoporosis. Does not replace bone mineral density (BMD) screening to diagnose osteoporosis.

Nutrition & Vitamins

Urinary vanillylmandelic acid (VMA) concentration is useful in the biochemical diagnosis and monitoring of neuroblastomas [1]. VMA measurement from random urine specimens, expressed as the ratio of VMA to creatinine, may provide equivalent diagnostic value as VMA measurement from 24-hour urine specimens for the evaluation of neuroblastomas [1].Neuroblastomas occur predominantly in children and are the most common malignancy under 1 year old. Neuroblastomas are catecholamine-metabolizing tumors with limited ability to store and secrete catecholamines. Thus, catecholamine metabolites-including VMA and homovanillic acid (HVA)-are more reliable than catecholamines as biochemical markers for neuroblastomas [1]. VMA and HVA levels, usually measured simultaneously, can be elevated in neuroblastomas as well as other catecholamine-secreting tumors, such as pheochromocytoma [1]. In patients with familial dysautonomia (Riley-Day syndrome), a neurological disorder found mainly in individuals of Ashkenazi Jewish descent, VMA levels are generally elevated while HVA levels may be normal or decreased [2].Urinary VMA and HVA levels may have limited accuracy for diagnosis of neuroblastomas with high-risk metastatic biology [1]. Because poor prognosis is associated with immaturity of catecholamine metabolism, dopamine levels in urine or blood have been proposed as an additional marker to aid in diagnosis and monitoring of neuroblastomas [3].The results of this test should be interpreted in the context of pertinent clinical and family history and physical examination findings.References1. Eisenhofer G. Monoamine-producing tumors. In: Rifai R, et al. eds.Tietz Textbook of Laboratory Medicine. 7th ed. Elsevier Inc; 2022.2. Axelrod FB. Familial dysautonomia.Muscle Nerve. 2004;29(3):352-363.3. Brodeur GM, et al.J Clin Oncol. 1993;11(8):1466-1477.

Nutrition & Vitamins

Assessment of hydration status and overall electrolyte balance.

Nutrition & Vitamins

This test detects and quantitates BK Virus DNA in urine specimens of kidney transplant recipients who are at risk of developing BKV-associated nephropathy (BKVAN) and associated hemorrhagic cystitis leading to kidney failure. Prospective viral load monitoring of BKV DNA in urine (and plasma) is useful to exclude a diagnosis of BKVAN and to monitor the course of BKV infection. The assay is calibrated to the First World Health Organization International Standard for BKV DNA with a Reportable Range of 200-100,000,000 IU/mL (2.30-8.00 log IU/mL).

Nutrition & Vitamins

Offered as part of multiple lab tests

Nutrition & Vitamins

Urinary free cortisol is useful in the detection of patients with Cushing's syndrome for whom free cortisol concentrations are elevated.

Nutrition & Vitamins

Cortisol is increased in Cushing's Disease and decreased in Addison's Disease (Adrenal insufficiency).

Nutrition & Vitamins

Cortisol is increased in Cushing's disease and decreased in Addison's disease (adrenal insufficiency).