The vitamins are an organic compound required as a nutrient in tiny amounts by an organism. Vitamins are classified by their biological and chemical activity. “Vitamin A”, which includes the compounds retinal, retinol, and four known carotenoids. Vitamers by definition are convertible to the active form of the vitamin in the body, which is a set of chemicals is grouped under an alphabetized vitamin “generic descriptor” title. Vitamins have diverse biochemical functions. The largest number of vitamins function as precursors for enzyme cofactors, that help enzymes in their work as catalysts in metabolism. The term vitamin was derived from “vitamine,” a combination word made up by Polish scientist Casimir Funk from vital and amine, meaning amine of life.