Abstract
The utilization of vitamin B, as affected by various levels of ingestion has been studied by comparing the retentions of eight young children during twenty-three metabolism periods. The dried food aliquots, dried feces, and concentrated urine from the children were assayed for their vitamin B content according to standardized technic. The unit of vitamin B selected as being most suitable to the short period type of assay employed was the quantity of vitamin B causing 1 gm. of gain. This unit is approximately equal to 2 Chase-Sherman units. The outstanding result of the investigation was the fact that increasingly higher retentions were obtained with higher intakes for each level of ingestion studied. On the basis of the ingestions giving the highest retentions, the optimum requirement of vitamin B by young children is estimated to be 20 units per kilogram of body weight, or about 40 Chase-Sherman units per kilogram per day.