Abstract
Vitamin action of riboflavin-2', 3', 4', 5'-tetranicotinate (B_2-Nic) was examined by using male albino rats. As a result, it was found that this compound possesses vitamin effect on rats, although its effect was somewhat lower than that of free riboflavin. This compound was also found to be somewhat inferior to free riboflavin in maintaining the hepatic and renal flavin levels. However, by increasing the dose of its administration, flavin levels of these organs can be elevated. It is suggested that the conversion form B_2-Nic to riboflavin in animal body is a rate-limiting step for the utilization of the riboflavin moiety of B_2-Nic.
