The Effect of Protein and B-Vitamin Levels of the Diet Upon the Tissue Content and Balance of Riboflavin and Nicotinic Acid in Rats

Abstract

The concentrations of riboflavin and nicotinic acid found in the carcasses of rats grown for 26 days on the four experimental diets were approximately the same, and were not affected by either minimal and high levels of the B-vitamin complex or low and high protein content of the diet. In the liver the concentrations of riboflavin and nicotinic acid varied directly with the level of protein in the diet and were independent of the vitamin intake. The concentrations of thiamine in the carcass and liver reflected the level of B-complex intake but were not affected by the level of protein in the diet. The deposition of fat in the liver and body was augmented by either increasing the B-complex supplement or lowering the protein content of the diet; the maximal effect was obtained on the low protein-high vitamin diet. Balance studies show a synthesis of nicotinic acid by all four groups of rats and an economy of utilization of riboflavin by rats on diets low in B-vitamins.