A vitamin is an organic molecule needed in trace amounts for normal growth and metabolic processes; vitamins usually serve as components of coenzymes.
Vitamins needed by humans:
- vitamin A (retinol, retinoic acid, antixerophthalmic vitamin)
Any chemical relative of retinol; this vitamin is the precursor of visual pigments and is vital for the differentiation of epithelial tissues. It is thought to have anticancer properties and is used to treat skin problems such as acne, wrinkling and icthyosis. This vitamin is found in liver oils and is synthesized from carotenoids.
- vitamin B1 (thiamine)
Vitamin B1 (thiamine) is a water-soluble vitamin the body needs to make enzymes to break down carbohydrates. It is found in foods such as beans, green vegetables, egg yolk, liver, corn, and brown rice.
- vitamin B12 (cobalamine)
This ring-shaped, cobalt-containing vitamin is a crucial part of the entry of amino acids and fatty acids into the Krebs cycle. It is the only biomolecule known to have a carbon-metal bond.
- vitamin B2 (riboflavin, lactoflavin)
A water-soluble vitamin that serves as a hydrogen carrier in coenzymes involved in oxidation-reduction metabolic processes, and as such is needed to properly process proteins and fats. It is found in milk, eggs, meats, and leafy vegetables.
- vitamin B3 (pantothenic acid)
A vitamin found in all human cells which is a constituent of coenzyme A; it is a vital nutrient for some animal species, but humans don't seem to show any ill effects from a dietary deficiency of this vitamin.
- vitamin B6 (pyridoxine, pyridoxal phosphate)
Any of the various derivatives of pyroxidine; this water-soluble vitamin is a critical coenzyme in the metabolism of amino acids. It is found in most foods, such as meats, liver, vegetables, whole-grain cereals and egg yolks.
- vitamin B7 (niacin, nicotinic acid)
This vitamin is necessary for the synthesis of various enzymes and acts to reduce blood cholesterol. A deficiency in this vitamin causes pellagra, which is characterized by dermatitis, diarrhea, and inflammation of the mucous membranes.
- vitamin H (biotin, coenzyme R, bioepiderm)
A water-soluble vitamin (a member of the B complex vitamins) that is important because it replenishes an intermediate in the Krebs cycle. It is also used in biochemistry to detect certain protein and DNA interactions.
- folic acid (folate, pteroylglutamic acid, PGA)
A vitamin in the B complex that is found in whole grains, fresh vegetables and is synthesized by certain nonpathogenic bacteria that live in the human intestine. A deficiency in this vitamin causes anemia and poor growth.
- vitamin C (ascorbic acid)
An important vitamin that the body needs to form collagen, a protein that makes up connective tissues. Collagen formed without ascorbic acid is structurally unsound, thus producing the skin lesions associated with the nutritional disease scurvy.
- vitamin D
This steroid vitamin is needed for calcium metabolism, and is found in egg yolk, fatty fish and enriched milk, but, since it is synthesized in the skin when an individual is exposed to sunlight, it isn't normally needed in the diet. It is used to treat rickets, a nutritional disease that causes poor bone growth in children.
- vitamin E (tocopherol)
Any of eight antioxidant, fat-soluble compounds found in vegetable oils. This vitamin is necessary for muscle and red blood cell development and normal reproduction. Deficiency in this vitamin causes excessively dry skin in some individuals.
- vitamin K
A fat-soluble vitamin needed to synthesize blood-clotting factors such as prothrombin; it is synthesized by certain harmless bacteria that normally live in the human intestine.
- biotin (vitamin H, coenzyme R, bioepiderm)
A water-soluble vitamin (a member of the B complex vitamins) that is important because it replenishes an intermediate in the Krebs cycle. It is also used in biochemistry to detect certain protein and DNA interactions.
- folic acid (folate, pteroylglutamic acid, PGA)
A vitamin in the B complex that is found in whole grains, fresh vegetables and is synthesized by certain nonpathogenic bacteria that live in the human intestine. A deficiency in this vitamin causes anemia and poor growth.
Other vitamins:
From the science dictionary at http://biotech.icmb.utexas.edu/