Racial contrasts in hemoglobin levels and dietary patterns related to hematopoiesis in children: the Bogalusa Heart Study.

Racial differences in hemoglobin (Hgb) levels were explored in two groups of children at different maturational stages, the pre-adolescent (10-year-olds: Whites n = 160, Blacks n = 56,) and the adolescent (15-year-olds; Whites n = 60, Blacks n = 44). Mean Hgb levels were higher for Whites than Blacks in both age groups. When all the dietary components (i.e., iron, zinc, copper, folacin, ascorbic acid and vitamins B12, E and B6) were considered as a group, they accounted for 8.4 per cent of the Hgb variance in 10-year-olds and 10.1 per cent of variance in 15-year-olds. However, even after controlling for the variations in dietary patterns of the adolescents and pre-adolescents, race still accounted for a notable proportion of Hgb variance in both age groups (9.1 per cent in 10-year-olds and 7.0 per cent in 15-year-olds). Within each race, gender accounted for a greater percentage of the Hgb variance in the adolescents than in the pre-adolescents. Our results indicate that in all likelihood racial differences in Hgb levels during childhood exist independent of racial differences in intake of specific "blood building" nutrients and maturational changes.