Thiamin, riboflavin, and pyridoxine excretion during acute starvation and calorie restriction

Abstract

Daily excretion of thiamin and vitamin B6in micrograms per gram creatinine were in the low-to-deficient ranges established by the ICNND during the calorie restriction period, indicating rapid depletion of body stores. Although riboflavin excretion decreased during the latter days of calorie restriction (studies I and II), these values remained in the high range of acceptability. The elevated excretions of riboflavin are indicative of adequate reserves and catabolism of body protein for use as energy, or both. These data suggest that under conditions of calorie restriction, the daily minimal allowances of vitamins B1, B2, and B6are influenced by the calorie, vitamin, and protein intakes, the degree of negative nitrogen balance, and the subsequent protein catabolism.