Serum transcobalamins in healthy Nigerian children.

The unsaturated vitamin B12-binding capacity (UB12BC) and the three transcobalamins (TC I, TC II, TC III) have been studied in the serum of normal healthy Nigerian children. The serum UB12BC level was very high in the children: TC I accounted for 39.5% of UB12BC, TC II accounted for 49.5% and TC III accounted for 11%. The results are discussed in the light of the variations in the distribution of transcobalamins in children from what has been previously reported among the African adults. The high percentage of TC I in the children is discussed in the light of a possible immunological role of this transcobalamin. There was an inverse relationship between TC I and TC II levels. A sex difference in UB12BC and TC I levels was observed. The girls had higher UB12BC and this was due to higher TC I, but the advantage of this is not clear.