Feeding of Vitamin B12 Rapidly Increases the Specific Activity of Hepatic Methyl-malonyl-CoA Mutase in Vitamin B12-Deficient Rats.

Vitamin B12-deficient rats were used to study the effects of feeding vitamin B12 on hepatic methylmalonyl-CoA mutase activity, which was decreased by the deficiency. A significant and rapid increase in the specific activity of the enzyme was caused by feeding vitamin B12, suggesting that the rate of synthesis of the enzyme protein is accelerated by the feeding.