Studies on B Vitamin Interrelationships in Growing Rats

Abstract

B vitamin interrelationships were studied in growing animals by giving male weanling rats otherwise adequate diets containing low, adequate or high levels of one B vitamin, in combination with low, adequate or high levels of a second B vitamin. In these experiments, the low levels of vitamins tested were one-twentieth those chosen as adequate, whereas the high levels were 50 times the adequate levels. Deficiency of thiamine, riboflavin, pyridoxine or pantothenate significantly reduced weight gain and food efficiency. The animals deficient in both thiamine and in a second B vitamin (riboflavin, pyridoxine or pantothenate), grew at rates comparable to those deficient in thiamine alone. High levels of thiamine had no influence on the weight gain and food efficiency of the rats fed diets deficient in pyridoxine, pantothenate or riboflavin. Similarly, no effects of high pyridoxine, pantothenate or riboflavin levels on the severity of thiamine deficiency were observed. In addition, no evidence was found of any interrelationship between high and low levels of pantothenate and riboflavin. A study was also made of the effects of administration of an excess level of thiamine, riboflavin, pyridoxine or pantothenate to animals deficient in the other three B vitamins. No adverse effects of high levels of thiamine, pyridoxine or pantothenate were observed. However, high dietary riboflavin significantly depressed weight gain and food efficiency, and increased the mortality of rats fed diets deficient in thiamine, pyridoxine and pantothenate.