Necessity of vitamin B12for growth of rats fed on an odd- or even-carbon-number fat

Abstract

1. The effect of vitamin B12on growth was studied in young male and female rats fed on diets sufficient (+B12) or deficient (−B12) in vitamin B12containing 30% of the dietary energy as fat, either maize oil (CO) or triundecanoin (TUD).2. Vitamin B12deficiency severely depressed growth. After 6 weeks the weight gain of CO(−B12) rats was only 72% of that of CO(+B12) rats and the gain of TUD(−B12) rats was only 47% of TUD(+B12) rats.3. After fasting 24 or 96 h TUD-fed rats, both + B12and −B12, had greater glycogen reserves and higher plasma glucose levels than CO-fed rats.4. It is concluded that vitamin B12is required for the metabolism and utilization of both an odd-carbon-number medium-chain fat, TUD, and an even-C-number long-chain fat, CO, during growth in rats.