Fat-Soluble Vitamins |
| Biochemical Action | Effects of Deficiency | Effects of Toxicity | Dietary Sources |
Vitamin A | Component of retinal pigments and rhodopsin for vision in
dim light, bone and tooth development; preserves integrity of epithelial
cells; promotes wound healing, and growth | Night blindness, xerophthalmia, photophobia, conjunctivitis,
Bitot spots, keratomalacia, hyperkeratosis of the skin and mucous membranes,
poor growth, impaired resistance to infection | Carotenemia with xanthosis cutis, night sweats, dry and cracking
skin, vertigo, hepatomegaly, vomiting, alopecia, increased cerebrospinal
fluid pressure | Liver, fish-liver oils, milk fat, egg yolk, butter, green
and deep yellow vegetables |
Vitamin D | Regulates absorption and deposition of calcium
and phosphorus, formation of calcium transport protein in duodenal
mucosa, synthesis of calcium-binding protein in epithelial cells | In infants and children: rickets. | In infants and children: hypercalcemia, anorexia, poor growth | Fortified milk, egg yolk, liver, salmon, butter, sardines, mackerel |
In adults: osteomalacia | In adults: nausea, vomiting, polydipsia,
polyuria, calcification of soft tissue including heart renal tubules
and bronchi |
Vitamin E | Antioxidant, role in red blood cell fragility, stabilizes
cell membranes, prevents peroxidation of unsaturated fatty acids | Hemolytic anemia in premature infants, loss of neural integrity, muscle
lesions, ceroid pigment deposition | Unknown | Vegetable oils, beef liver, seed oils, peanuts, soybeans,
milk fat, turnip greens, eggs, butter, leafy vegetables |
Vitamin K | Catalyzes prothrombin synthesis; coagulation factors II,
VII, IX, X; proteins C, S, Z | Hemorrhagic manifestations | Kernicterus (water-soluble analogs only) | Vegetable oils, liver, pork, green leafy vegetables (also
synthesized by normal intestinal flora) |
Water-Soluble Vitamins |
| Biochemical Action | Effects of Deficiency | Effects of Toxicity | Dietary Sources |
Thiamin | Combines with phosphorus to form thiamin pyrophosphate, which acts in various oxidative decarboxylations, including pyruvic acid | Wet beriberi: congestive heart failure, tachycardia, peripheral edema | Unknown | Liver, meat, milk, pork, whole grains, legumes, nuts |
Dry beriberi: neuritis, paresthesia, irritability, anorexia |
Riboflavin | Part of the flavin coenzymes, FAD and FMN, necessary for
tissue oxidation and respiration and synthesis of FMN and FAD essential for
growth, retinal pigment for light adaptation | Photophobia, loss of visual acuity, burning and itching of eyes,
corneal vascularization, glossitis, seborrheic dermatitis, poor
growth, cheilosis | Unknown | Milk, cheese, eggs, organ meats, fish, green leafy vegetables, whole
and enriched grains |
Niacin | Component of coenzymes I and II (NAD, NADP), cofactors in
a number of dehydrogenase systems, necessary for synthesis of glycogen
and breakdown of fatty acids | Pellagra: dermatitis, apathy, anorexia,
peripheral neuropathy, encephalopathy with some degree of dementia,
diarrhea secondary to atrophy of mucosa | Nicotinic acid has transient vasodilating effects, skin flushing,
tingling, itching, dizziness, nausea; may induce liver abnormalities | Lean meats, poultry, peanuts, organ meats, brewer’s
yeast, green vegetables, enriched cereals and grains |
Folate | Tetrahydrofolic acid is the active form; essential in the
biosynthesis of purines, pyrimidines, and nucleoproteins; methylation
reactions; 1-carbon acceptor | Megaloblastic anemia (should also suspect concurrent vitamin
B12 deficiency), impaired cellular immunity, poor growth,
glossitis, gastrointestinal disturbances | Unknown | Liver, green leafy vegetables, legumes, asparagus, broccoli, nuts,
cheese |
Vitamin B6 | Constituent of many coenzymes for decarboxylation, transamination, transsulfuration,
role in hemoglobin synthesis and fatty acid metabolism | Dermatitis, cheilosis, stomatitis, peripheral neuritis (in
patients on isoniazid), microcytic, hypochromic anemia, irritability,
convulsions | Sensory neuropathy with progressive ataxia, altered sense
of touch, pain, fever | Liver, meat, whole grains, yeast, potatoes, corn, soybeans, bananas,
peanuts |
Vitamin B12 | Essential for red blood cell maturation in bone marrow, coenzyme for
methylmalonyl CoA mutase, transfer of 1-carbon units in purine metabolism,
affects central nervous system metabolism | Pernicious anemia, neurologic deterioration because of demyelination
of large nerve fibers of the spinal cord, methylmalonic aciduria,
homocystinuria | Unknown | Liver, organ meats, meat, eggs, cheese, fish |
Biotin | Coenzyme of all carboxylases and of carbon dioxide | Leiner dermatitis, anorexia, glossitis, alopecia, nausea,
anorexia, muscle pain, insomnia | Unknown | Liver, kidney, milk, egg yolk, yeast, mushrooms, banana, watermelon,
strawberries, grapefruit |
Pantothenic acid | Component of CoA; necessary for fat, protein, and CHO metabolism;
fatty acid biosynthesis | Observed with use of antagonists, depression, hypotension,
muscle weakness, nausea, sleep disturbances, abdominal pain, loss
of antibody production | Unknown | Most foods |
Vitamin C | Integrity maintenance of all intercellular materials, collagen
biosynthesis, iron absorption and transport, metabolism of tyrosine, synthesis
of corticosteroids | Scurvy: diffuse tissue bleeding, pinpoint
peripheral hemorrhages, easy bone fracture, poor wound healing,
friable bleeding gums with loose teeth | Nausea, diarrhea, cramps; massive doses may predispose to
kidney stones | Citrus fruits, tomatoes, berries, green vegetables, cabbage, human
milk |