Low-dose weekly supplementation with iron and/or zinc does not affect growth among Bangladeshi infants.

Background: Micronutrient malnutrition is a widespread problem in developing countries. Supplemental zinc has been shown to improve growth in undernourished children, but the effect in infants or when combined with iron is less known. We assessed the effect of low-dose weekly zinc and/or iron supplementation on growth among infants from 6-12 mo of age. Methods: Bangladeshi infants were randomized to receive 20 mg iron (Fe), 20 mg zinc (Zn), both (Fe + Zn), or riboflavin alone weekly from 6-12 mo of age. Weight and length were assessed fit baseline, 8, 10, and 12 mo of age. Changes in anthropometric indicators were compared using multiple linear regression analyses and 6-mo growth trajectories were compared by supplementation groups for all infants and in stratified analyses by baseline Hb concentration. Results: Baseline characteristics were similar among the 4 groups. Overall, z-scores declined over the 6 month period. There was no effect of Fe, Zn, or both on length. Fe + Zn had a negative effect on weight, yet supplementation with Fe or Zn alone had no effect. There was no differential effect by supplement type when stratified by Hb concentration. Fe or Zn alone decreased the rate of weight gain, but these small effects were not observed in the Fe + Zn group. Conclusions: Low-dose weekly supplementation with Fe and/or Zn does not benefit growth among infants 6-12 mo of age. [ABSTRACT FROM AUTHOR]