| Vitamin |
Chief Functions |
Results of Deficiency or Overdose |
Characteristics |
Good Sources |
VITAMIN A
Retinol (animal sources)
Carotene
Beta-carotene (plant sources) |
- Maintains epithelial membranes; functions in infection resistance; needed to form rhodopsin; prevents night blindness; ensures proper bone growth; facilitates RNA transcription.
|
-
Deficiency: Increased susceptibility to infection; abnormal function of gastrointestinal, genitourinary, and respiratory tracts; skin dries, shrivels, thickens; sometimes pustule formation; xerophthalmia, a characteristic eye disease.
-
Overdose: Bleeding disorders; bone decalcification; immune system stimulation; fatigue; nausea; diarrhea; dry skin; brittle nails; jaundice.
|
- Fat soluble; stable during cooking; destroyed by heat and oxygen together; marked capacity for storage in the liver.
|
- Liver; dark green leafy vegetables, esp. escarole, kale, and parsley; yellow-orange fruits, esp. carrots, apricots, and cantaloupe; butter or fortified margarine; milk and dairy products; meats, fish, and poultry.
|
VITAMIN B1
Thiamine |
- Involved in carbohydrate metabolism; essential for normal nervous tissue function; acts as a coenzyme for cellular energy production.
|
-
Deficiency: Weakness; wasting; mental confusion; peripheral paralysis; edema; beriberi.
|
- Water soluble; stable during most cooking; destroyed by alkali or sulfites; not stored in the body. Note: Deficiency often accompanies alcoholism.
|
- Brewer's yeast; pork; soy milk; liver; milk; enriched or whole-grain cereals; beans; nuts.
|
VITAMIN B2
Riboflavin |
- Acts as a coenzyme in cellular oxidation; essential to normal growth; participates in light adaptation; vital to protein metabolism; associated with functions of niacin and vitamin B6.
|
-
Deficiency: Cheilosis; glossitis; dermatitis around mouth and nose; corneal reddening; light hypersensitivity.
|
- Water soluble; alcohol soluble; stable during most cooking; destroyed by alkali; unstable in light.
|
- Milk and dairy products; collard greens; broccoli; whole-grain or enriched breads and cereals; liver; meat, fish, and poultry; eggs; legumes.
|
VITAMIN B6
Pyridoxine
Pyridoxal
Pyridoxamine |
- Used in hemoglobin synthesis; essential for metabolism of tryptophan to niacin; needed for utilization of other amino acids.
|
-
Deficiency: Anemias; depressed immunity; dermatitis around mouth and nose; neuritis; anorexia; nausea; vomiting.
|
- Water soluble; alcohol soluble; inactivated by heat, sunlight, or air.
|
- Meats; liver; cereal grains; bananas; nuts.
|
VITAMIN B12
Cyanocobalamin
Hydroxycobalamin |
- Needed for myelin synthesis; essential for proper red blood cell development; associated with folate metabolism.
|
-
Deficiency: Pernicious anemia; neurological disorders.
|
- Water soluble; alcohol soluble; unstable in hot alkaline or acid solutions.
|
- Synthesized by gastrointestinal flora; meat; yeast; milk; eggs.
|
VITAMIN C
Ascorbic acid |
- Acts as an antioxidant; essential to formation of the protein collagen; facilitates iron absorption; facilitates cholesterol conversion to bile acids; essential to serotonin synthesis.
|
-
Deficiency: Joint tenderness; lowered resistance to infections; susceptibility to dental caries, pyorrhea, and bleeding gums; delayed wound healing; bruising; anemia; hemorrhaging; scurvy.
-
Overdose: Nausea; diarrhea; hemolytic anemia; gout; kidney stones.
|
- Water soluble; destroyed by light; heat hastens the process; lost in cooking when water is discarded; cooking loss is increased in iron or copper utensils.
- Stored in the body to a limited extent.
|
- Citrus fruit; strawberries; green peppers; mustard greens; cauliflower.
|
VITAMIN D
Calciferol
Ergocalciferol
Cholecalciferol
Calcitriol
Antirachitic factor |
- Promotes gastrointestinal absorption of calcium and phosphorus; promotes bone and tooth mineralization; promotes renal calcium absorption; antirachitic.
|
-
Deficiency: Interferes with utilization of calcium and phosphorus in bone and tooth formation; irritability; weakness; rickets in young children; osteomalacia in adults.
-
Overdose: Irritability; kidney stone formation; calcification of soft tissues.
|
- Fat soluble; soluble in organic solvents; relatively stable when refrigerated; stored in liver; often associated with vitamin A.
|
- Formed in the skin by sunlight exposure; fortified milk and dairy products; egg yolks; liver; fatty fish, esp. salmon, tuna, herring, and sardines; oysters.
|
VITAMIN E
Alpha-tocopherol
Beta-tocopherol
Gamma-tocopherol |
- Prevents oxidative damage of lipids and cell membranes; promotes red blood cell stability.
|
-
Deficiency: Immune system suppression; red blood cell hemolysis.
|
- Fat soluble; destroyed by heat; destroyed by oxidation.
|
- Vegetable oils, esp. soybean and corn; wheat germ.
|
FOLATE
Folacin
Folic acid |
- Needed for normal hematopoiesis; important coenzyme for nucleic acid synthesis; facilitates fetal development for neural tube closure; functions interrelated with those of vitamin B12.
|
-
Deficiency: Note: Neural tube defects including spina bifida and anencephalus are associated with maternal deficiency; alcohol interferes with absorption; diarrhea; glossitis; macrocytic anemia.
-
Overdose: Masking of vitamin12 deficiency, which may lead to nerve damage.
|
- Slightly water soluble; destroyed by heat at low pH; loss in food stored at room temperature.
|
- Liver; green leafy vegetables; legumes; beets; broccoli; cauliflower; citrus fruits; sweet potatoes.
|
VITAMIN K
Phylloquinone (plant form)
Menaquinone (bacterial form) |
- Regulates blood coagulation; regulates blood Ca++ levels.
|
-
Deficiency: Hemorrhagic disease; fat malabsorption can cause deficiency.
-
Overdose: Kernicterus.
|
- Fat soluble; stable to heat.
|
- Produced by gastrointestinal flora; green leafy vegetables, esp. broccoli; cauliflower; liver.
|
NIACIN
Nicotinic acid
Nicotinamide |
- Facilitates glycolysis, tissue respiration, fat synthesis, and cellular energy production.
|
-
Deficiency: Dermatitis; edema; diarrhea; irritability; mental confusion.
-
Overdose: Flushed skin; intestinal irritation; liver damage.
|
- Soluble in hot water and alcohol; stable during cooking; not destroyed by light, air, or alkali.
|
- Milk; eggs; meat; legumes; whole-grain or enriched breads and cereals.
- Note: Also formed in the body from dietary tryptophan (amino acid).
|
See App. 1-2 for recommended daily allowances.
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