Vitamins (organic compound and vital nutrient) are necessary nutrients for growth and development of a multicellular organism. Vitamins facilitate chemical reactions in the body and enable it to produce muscle, bone and skin.
Thirteen vitamins are universally recognized at present. Vitamins are classified by their biological and chemical activity, not their structure. Thus, each “vitamin” refers to a number of vitamer compounds that all show the biological activity associated with a particular vitamin. Vitamers by definition are convertible to the active form of the vitamin in the body, and are sometimes inter-convertible to one another, as well.
Vitamins have diverse biochemical functions. Some, such as vitamin D, have hormone-like functions as regulators of mineral metabolism, or regulators of cell and tissue growth and differentiation (such as some forms of vitamin A). Others function as antioxidants (e.g., vitamin E and sometimes vitamin C). The largest number of vitamins, the B complex vitamins, function as precursors for enzyme cofactors, that help enzymes in their work as catalysts in metabolism.
For a healthy individual vitamins are primarily obtained from food. A few vitamins are obtained by other means. A few examples of non-food derived vitamins are:
If there is serious deficiency in one or more of these nutrients, a child may develop a deficiency disease. Even minor deficiencies may cause permanent damage. Once body growth and development are completed, vitamins retains their status of essential nutrients for the healthy maintenance of the cells, tissues, and organs. Vitamins also enable a our body to efficiently use chemical energy provided by food it eats, and to help process the proteins, carbohydrates, and fats required for respiration.