The Effect of Vitamin B12 Deficiency upon the Survival of Young Born to Rats Fed Purified Casein Rations

Abstract

Results have been presented dealing with the survival of newborn rats on a number of B12-deficient casein-containing rations. A very high percentage of deaths within the first few days after birth was found to occur on such rations when they contained crystalline B vitamins (except B12) in place of yeast, and in some experiments when they contained yeast instead of the B vitamins. Some rats failed to show this phenomenon, the “resistance” in at least one line persisting through several generations. Early deaths were not due to a failure of the mothers to secrete milk. Not only was the presence of considerable milk observed in the stomachs of the dead young, but in addition deficient mothers raised stock young while stock mothers generally failed to raise deficient young. Vitamin B12 supplementation of the rations either prevented the occurrence of this phenomenon or restored survival to normal in most but not all cases; yeast-containing rations were somewhat but not greatly superior to yeast-free rations in this respect. No significant difference was found between the food consumption of B12-deficient and B12-supplemented mothers during gestation.