Vitamins are a group of compounds indispensable for the development, normal growth and functioning of the human body. Lack of vitamins causes serious diseases for human, even though small amounts of them are required to maintain good health. Therefore there is growing interest concerning the role of vitamins in physiological conditions. This article reviews the role of vitamins (water-soluble): PP, B6 and C in metabolic processes, discuss criteria used for recommended ingestion of the vitamins, and presents recommendations for these vitamins intake. In this paper we discussed vitamins in detail including their chemical structure, chemical activity and biological properties.