The utility of reported data on the minimum requirements of vitamins was examined by testing the growth-promoting activity for young carp of a vitamin mixture representing them. The vitamin mixture failed to sustain the growth of carp, but could maintain the growth almost normally, when enriched with thiamine, riboflavin, and niacin. It is suggested that minimum requirements for these three vitamins, especially for niacin, are greatly in-fluenced by the quantity of some other vitamins present.
