A comparison of serum transcobalamin levels in white and black subjects.

Serum transcobalamins (TC) have been measured in 82 white and 79 Black healthy adults, 170 white and 73 Black pregnant subjects and in cord blood samples from 33 whites and 13 Blacks. Healthy Black adults had significantly higher mean TC I, TC II, and TC III levels than white adults of the same sex. These differences in mean TC levels persisted at all stages of pregnancy. Mean cord blood levels of TC II and TC III were significantly higher in Blacks than in whites. No environmental factors could be identified to account for these differences, which are probably genetically determined.