Plasma retinol-binding protein levels of children under five years of age in a displaced Sudanese community.

Blood samples (100-160 microliters) were obtained from 1360 children by a finger prick in heparinized collection tubes, and an LC-Partigen retinol-binding protein (RBP) kit was used for quantification of RBP in the plasma. Only three boys and two girls had plasma RBP that was equal to or more than 3.0 mg/dL, a recommended cut-off point for normal values. The mean +/- SD) plasma RBP levels were at 1.150 +/- 0.613 mg/dL for boys (N = 689) and 1.233 +/- 0.572 mg/dL for girls (N = 671). The difference between boys and girls was statistically significant (p < 0.001). None of the children included in this study had eye signs of vitamin A deficiency. Two hundred eighty-two children (19.6%) received vitamin A supplements (200,000 IU) before the beginning of the study. The mean +/- SD for plasma RBP for children who received vitamin A supplement were 1.159 +/- .762 mg/dL for boys and 1.151 +/- 0.470 mg/dL for girls. The observed discrepancy between the biochemical and clinical manifestations of vitamin A deficiency was discussed.