Vitamin



Vitamins are organic compounds (mixtures made from living organisms like plant and animal tissue). They are generally divided into two groups: fat-soluble and water-soluble. Fat-soluble vitamins include vitamins A, D, E and K. Water-soluble vitamins are those in the B group and vitamin C.

Many people think they can improve their health by taking vitamin pills. Most medical experts believe this is unnecessary. The experts say that eating a varied diet of fresh food and exposing the skin to enough sunlight to increase vitamin D reserves (but not enough to burn the skin) should provide enough vitamins under most circumstances. In fact, over-dosing on some vitamins can itself cause disease.

Only tiny amounts of each of the 13 vitamins are needed to ensure metabolism, but these minimum amounts are absolutely essential. The continued lack of any vitamin, even in an otherwise balanced diet, usually leads to a deficiency disease. Vitamins were discovered as scientists searched for the causes of deficiency diseases like pellagra, beriberi, and scurvy.

Vitamins and Enzyme Reactions

While vitamins are not all chemically related, they all serve a common purpose. That purpose is helping to regulate how the body converts food into energy and living tissues (metabolism). Most vitamins accomplish this by acting as enzymes. Enzymes are chemicals which encourage chemical reactions, but are neither changed by the reaction nor are they incorporated into the reactions's final product.

Many vitamins, including all of the eight vitamins in the B group, are inactive until converted into coenzymes. Coenzymes are organic substances which combine with a protein to form an active enzyme system. The human body needs vitamins to work properly. We acquire almost all of the vitamins from the foods we eat. A small number of vitamins, including biotin and vitamin K, are at least partially synthesized (created) by the body itself.

How Vitamins Got Their Names

In the early part of the twentieth century, Polish biochemist Casimir Funk studied the various "accessory food factors" that had been identified. He suggested these factors be named "vitamines" or "amine compounds vital for life" (amines are organic compounds of nitrogen). After it became clear that not all these compounds were amines, the final "e" was dropped, and the substances became known as vitamins.

[See also Biotin ; Vitamin A ]



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