Sex-specific responses to zinc supplementation in Nouna, Burkina Faso

Objectives: To study the different responses by sex to zinc supplementation among young children. Study Children and Methods: Double-blind randomized controlled trial of zinc supplementation in 686 children aged 6-30 months, conducted in Nouna, a rural area of Burkina Faso. Children received either a 12.5-mg zinc sulfate tablet or a placebo every day for about 6 months. Outcomes were morbidity, nutritional status, and mortality. Results: Results revealed significant differences between boys and girls in their responses to zinc supplementation. Boys who received the zinc preparation had fewer days with diarrhea than did control boys (RR = 0.88, P = 0.05), especially less nonfebrile diarrhea (RR = 0.72, P < 0.001) and less dysentery (RR = 0.65, P = 0.05), but more ear infections (RR = 4.00, P < 0.001). By contrast, girls who received the zinc supplement had the same prevalence of diarrhea as did control girls, but more dysentery (RR = 3.70, P < 0.001), fewer ear infections (RR = 0.39, P < 0.001), and fewer eye infections (RR = 0.41, P < 0.001). The effect of supplementation on nutritional status was not detectable in boys, but girls who received supplementation experienced a faster growth velocity in height than did control girls (P = 0.004) and a faster growth velocity for weight and height if they were wasted and not stunted at baseline (P = 0.003). Conclusions: Zinc supplementation had positive, nil, or negative effects depending on pathological condition, and the effects were different for boys than for girls.