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- Vitamin
- vitamin (vì¹te-mîn) noun Any of various fat-soluble or water-soluble
organic substances essential in minute amounts for normal growth and activity of the body
and obtained naturally from plant and animal foods.
- [Alteration of vitamine : Latin vìta, life + AMINE (so called because
they were originally thought to be amines).]2
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- vitamin (vì¹te-mîn), organic compound required in the diet of animals,
including humans, for normal growth and maintenance of life. Vitamins provide the only
source of certain COENZYMES necessary for METABOLISM, the biochemical processes that
support life. Since vitamins differ widely in chemical structure, there is no common
chemical grouping. They were originally classified as fat-soluble or water-soluble, but as
more were discovered, they were also classified alphabetically. The fat-soluble vitamins
are stored in body fat and may therefore accumulate in quantities that can be toxic;
vitamins A, D, E, and K are fat-soluble. Most water-soluble vitamins are rapidly excreted
in the urine and thus rarely cause toxicity, even when ingested in excessive amounts; the
B-complex vitamins and vitamin C are water-soluble. A well-balanced diet—including
sufficient amounts of fruit and vegetables as well as eggs, meat, fish, or fowl (that is,
a good source of protein)—usually satisfies the minimum vitamin requirement of human
beings. An inadequate vitamin intake can lead to deficiency diseases, but there is growing
evidence that vitamins have roles in health beyond the prevention of deficiency diseases.
Vitamins C and E act as ANTIOXIDANTS and may prevent LDL CHOLESTEROL from clogging
arteries, and vitamin K inhibits loss of bone calcium in post-menopausal women.1
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