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Disease Categories > Gastrointestinal Disease > Nutritional Assessment

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Vitamins

Vitamins are required in the diet since they are not adequately synthesized in the human body.

Only small amounts are necessary to catalyze the essential biochemical reactions
Deficiencies are rare in healthy patients in the U.S.
- Exception is in gastric bypass patients
Disease states generally result from poor diet
Body stores vary by vitamin
- Thiamine (B₁) and folate stores are small and rapidly depleted
- Cobalamin (B₁₂) stores are large
Vitamins play several roles in disease processes
- Diseases can cause vitamin deficiency
- Vitamin deficiency or excess can cause disease
- High doses of certain vitamins can be used to manage some diseases

Water Soluble Vitamins
Vitamin	Disease States
B₁ (thiamine) Catalyzes reactions that produce energy Sources — legumes, whole grains, nuts Inhibitors — tea, coffee, raw fish, shellfish, alcohol	Vitamin B₁ deficiency Mainly found in alcoholics in U.S. Wet beriberi — cardiac high output failure Dry beriberi — symmetrical peripheral neuropathy Wernicke encephalopathy Beriberi combined with alcoholism Horizontal nystagmus, ophthalmoplegia, cerebellar ataxia, mental impairment Wernicke-Korsakoff syndrome Coexistence of additional loss of memory and confabulatory psychosis Vitamin B₁ toxicity— rare reports of anaphylaxis
B₂ (riboflavin) Catalyzes reactions that produce energy; coenzyme in the flavoproteins that participate in tissue oxidation and respiration processes Sources — milk, dairy products, enriched breads, lean meats, fish, eggs, broccoli, legumes Inhibitors — sunlight rapidly degrades the vitamin in foodstuffs	Vitamin B₂ deficiency Mucocutaneous lesions including magenta tongue, angular stomatosis, seborrhea, cheilosis Vitamin B₂ toxicity None reported; gastrointestinal tract can only absorb limited quantities
B₃ (niacin) Catalyzes the metabolism of fatty acids, amino acids and carbohydrates Sources — beans, milk, meat, eggs Inhibitors — B₆ or B₂ deficiency reduces conversion of tryptophan to niacin; drugs that may interfere with metabolism include chlorpromazine, imipramine, amitriptyline, alcohol	Vitamin B₃ deficiency Pellagra Mainly found in alcoholics in U.S. Can occur in carcinoid, Hartnup disease Pigmented rash in sun exposed areas (Casal necklace), bright red tongue, diarrhea, apathy As drug therapy, flushing and headache frequently accompany treatment doses Vitamin B₃ toxicity Hepatotoxicity is most serious problem Glucose intolerance, macular edema, macular cysts
B₅ (pantothenic acid) Functions in the metabolism and biosynthesis of many compounds Sources — liver, yeast, egg yolk, broccoli Inhibitors — none	Vitamin B₅ deficiency Deficiency has only been demonstrated experimentally, may have caused burning feet syndrome in prisoners Gastrointestinal disturbance, depression, paresthesias, ataxia, hypoglycemia Vitamin B₅ toxicity — none reported
B₆ (pyridoxine) Coenzyme in transaminase reactions Sources —legumes, nuts, wheat bran, meats Inhibitors — drugs such as isoniazid, penicillamine, cycloserine, L-dopa	Vitamin B₆ deficiency Seborrhea, glossitis, convulsions, neuropathy, depression, confusion, microcytic anemia Vitamin B₆ toxicity — severe sensory neuropathy
Folate Coenzyme in metabolic reactions Sources — fruit, leafy vegetables, yeast, organ meats Inhibitors — chemotherapy agents, methotrexate, anticonvulsants, malabsorptive disorders (sprue)	Folate deficiency Megaloblastic anemia Fetal open neural tube defects No neurologic symptoms Folate toxicity — none reported
B₁₂ (cobalamin) Cofactor for enzymatic reactions, metabolism of odd chain fatty acids, and methylation of homocysteine Sources — animal products, dairy products Inhibitors — achlorhydria, proton-pump inhibitor drugs, overgrowth of intestinal organisms (e.g., short bowel syndrome)	Vitamin B₁₂ deficiency Megaloblastic (macrocytic) anemia Neurologic manifestations — loss of vibratory and position sense, abnormal gait, dementia, loss of bowel and bladder control Vitamin B₁₂ toxicity — none reported
Biotin Coenzyme in transfer of carbonyl groups Sources — liver, soy, beans, yeast, egg yolks Inhibitors — egg whites	Biotin deficiency Only demonstrated in patients with short bowel syndrome receiving total parenteral nutrition Adults — mental status changes, anorexia, nausea, seborrheic rash Infants — hypotonia, lethargy, apathy, alopecia and rash on ears Biotin toxicity — None reported
C (ascorbic acid) Coenzyme in formation of collagen and synthetic reactions Has antioxidant activity and is a free radical scavenger Sources — citrus fruits, green vegetables, tomatoes, potatoes Inhibitors — smoking, hemodialysis	Vitamin C deficiency Scurvy - bleeding into skin, inflamed and bleeding gums, bleeding into joints, impaired bone growth Vitamin C toxicity — elevated liver enzymes, abdominal pain, diarrhea

Fat Soluble Vitamins
Vitamin	Disease States
A (retinol) Required for normal vision, growth and differentiation of epithelial tissue as well as bone growth, immunity, reproduction and embryonic development Sources — vegetables, liver, fish Inhibitors — ethanol, mineral oil, neomycin, cholestyramine	Vitamin A deficiency Ophthalmic — xerophthalmia, Bitot spots, corneal ulcers Dermatologic — Hyperkeratotic skin lesions Vitamin A toxicity Acute — increased intracranial pressure, vertigo, diplopia, seizures Chronic — cheilosis, glossitis, alopecia, bone pain, hyperlipidemia, liver fibrosis
D (calcitrol) Hormone precursor Required for calcium absorption, bone metabolism, regulation of cell development and the immune system Sources — dairy, fish oils, egg yolks, also synthesized in response to ultraviolet radiation Inhibitors — sunblock, phenytoin, rifampin, barbiturates, isoniazid	Vitamin D deficiency Children — rickets and rachitic rosaries (expansion of growth plate) Adults — osteomalacia Hypocalcemia and hypophosphatemia with impaired mineralization of bone matrix Vitamin D toxicity Rare; associated with ≥ 10,000 IU/day intake (Not seen until 25(OH)D ≥ 250 mmol/L)
E (tocopherol) Coenzyme in formation of collagen, synthetic reactions, antioxidant activity and free radical scavenger Sources — sunflower oil, safflower oil, wheat germ, soybean Inhibitors — none	Vitamin E deficiency Almost exclusively in severe and prolonged malabsorptive disorders Peripheral neuropathy — areflexia, ataxia, ophthalmoplegia, skeletal myopathy Vitamin E toxicity — reduced platelet aggregation, interference with warfarin treatment
K (phylloquinone, menaquinone) Essential for carboxylation of glutamic acid residues and some proteins Sources — green leafy vegetables, butter, milk, ground beef, coffee, pears Inhibitors — broad spectrum antibiotics	Vitamin K deficiency Hemorrhage of mucous membranes and gastrointestinal tract Vitamin K toxicity Infants — hemolytic anemia and hypobilirubinemia

Indications for Ordering

Tests generally appear in the order most useful for common clinical situations
Click on number for test-specific information in the ARUP Laboratory Test Directory

Test Name and Number	Recommended Use	Limitations
Vitamin B₁ (Thiamine), Whole Blood 0080388 Method: High Performance Liquid Chromatography	Preferred specimen for thiamine assessment in patients with suspected deficiency or to monitor vitamin B₁ concentration in patients receiving supplementation
Vitamin B₁ (Thiamine), Plasma 0080389 Method: High Performance Liquid Chromatography	Assess thiamine concentration in plasma
Vitamin B₂ (Riboflavin) 0081123 Method: High Performance Liquid Chromatography	Assess riboflavin concentration in serum or plasma
Niacin (Vitamin B₃) 0092168 Method: High Performance Liquid Chromatography/Solid Phase Extraction	Assess niacin concentration in plasma
Vitamin B₆ (Pyridoxine), Total, Plasma 0080111 Method: Radioenzymatic Assay	Assess pyridoxine concentration in plasma	This assay does not distinguish among pyridoxine, pyridoxamine and pyridoxal forms, and does not detect pyridoxic acid
Vitamin B₁₂ & Folate 0070160 Method: Chemiluminescent Immunoassay	Assess vitamin B₁₂ and folate concentration
Vitamin B₁₂ with Reflex to Methylmalonic Acid (MMA), Serum Quantitative 0055662 Method: Chemiluminescent Immunoassay/Tandem Mass Spectrometry	Assess vitamin B₁₂ concentration Rule out pernicious anemia
Folate, RBC 0070385 Method: Chemiluminescent Immunoassay	Preferred specimen for assessment of folate concentration
Vitamin C, Plasma 0080380 Method: Spectrophotometry	Assess vitamin C concentration
Vitamin A (Retinol), Serum or Plasma 0080525 Method: High Performance Liquid Chromatography	Assess retinyl palmitate concentration	This assay does not measure other vitamin A metabolites such as retinaldehyde or retinoic acid
Vitamin D, 25-Hydroxy 0080379 Method: Chemiluminescent Immunoassay	Assess vitamin D concentration
Vitamin D, 25-Hydroxy by RIA 0070277 Method: Radioimmunoassay	Assess vitamin D concentration
Vitamin D, 1, 25-Dihydroxy 0080385 Method: Radioimmunoassay	Assess vitamin D concentration
Vitamin E, Serum or Plasma 0080521 Method: High Performance Liquid Chromatography	Assess vitamin E concentration Includes measurement of alpha tocopherol and gamma tocopherol concentrations
Vitamin K₁, Serum 0099225 Method: High Performance Liquid Chromatography	Assess vitamin K₁ concentration

Additional Tests Available

Click on number for test-specific information in the ARUP Laboratory Test Directory

Test Name and Number	Comments
Vitamin B₁₂ 0070150 Method: Chemiluminescent Immunoassay	Assess vitamin B₁₂ concentration
Folate, Serum 0070070 Method: Chemiluminescent Immunoassay	Assess folate concentration in serum