The Cobalamin-Binding Proteins Transcobalamin and Haptocorrin in Maternal and

Background: Two proteins carry vitamin B12 in plasma. Transcobalamin (TC) carries 25 % of total plasma vita-min B12 and is 6 % to 20 % saturated with cobalamin. Haptocorrin (HC) binds 80 % of total cobalamin and is largely saturated with cobalamin. Methods: We investigated the distribution and the relationship between concentrations of cobalamin, total and holo forms of TC, and HC in blood samples from pregnant women just before delivery (n 92) and in cord blood samples from their newborn babies. We also investigated the relationship between these proteins and concentrations of methylmalonic acid (MMA), the functional marker of vitamin B12 status. Results: Concentrations of total serum cobalamin, total HC, holoHC, and percentage of HC saturation wer