In review articles, vitamins are usually arranged either alphabetically or with regard to their specific physiological and curative effects. Such formal classification presents vitamins as coenzymes acting rather individually and independently. In fact, they cooperate mutually as well as with other factors to ensure optimal orchestration of biochemical reactions aimed to maintain cell homeostasis. With the assistance of vitamins, molecules of nutrients supplied in heterogeneous food must be first chemically homogenized and prearranged to stepwise release their protons and electrons to be rendered for cell respiration, energy formation and storage. In parallel, vitamins assist also in protection of cell structures from radicals. General revaluation of complex dynamic processes assisted by vitamins makes it to systemize them with regard to their successive cooperation, participation in the basic metabolic process „from food to energy“. The proposed vitamin systematization is in keeping with the principle „from the simple to the complex“. This concerns both the degree of complexity and specifity of the biochemical reactions themselves as well as that of the appropriate control and protective mechanisms. Based on the present knowledge of activities of vitamin cofactors we start with pyridoxine (vitamin B6). It participates in numerous enzyme reactions in the first step of nutrient homogenization concerning proteins, saccharides and fats. The homologized products of those processes serve subsequently as substrates for consecutive reactions catalyzed under increasingly specialized conditions by other vitamins in the following order: pantothenate, thiamin (B1), biotin, niacin, riboflavin (B2), pteroylglutamate (folate), cobalamine (B12), ascorbate (C).A short chapter is devoted to free radicals and their role in the functions of the four last mentioned hydrophil vitamins, as well as of the following lipophil ones: E, A, K and D which function mainly on interfacial membrane structures. The main results of our considerations are presented in Figures and Tables.

        Key words: cooperation of vitamins, citrate cycle, thiolic subtances, free radicals.