Different Doses, Forms, and Frequencies of Zinc Supplementation for the Prevention of Diarrhea and Promotion of Linear Growth among Young Bangladeshi Children: A Six-arm, Randomized, Community-based Efficacy Trial.
Abstract
Background
Children in resource-limited settings remain vulnerable to zinc deficiency and its consequences.
Objectives
To evaluate the effects of different doses, durations, and frequencies of zinc supplementation on the incidence of diarrhea and change in linear growth among young children.
Design
We conducted a randomized, partially double-blind, controlled, six-arm, community-based efficacy trial in Dhaka, Bangladesh. Children 9-11 months of age were randomized to receive one of the following interventions for 24 weeks: 1) Standard micronutrient powder (MNP) containing 4.1 mg zinc and 10 mg iron, daily; 2) High-zinc (10 mg), low-iron (6 mg) (HiZn LoFe) MNP, daily; 3) HiZn (10 mg) LoFe (6 mg)/HiZn (10 mg), no-iron MNPs on alternating days; 4) Dispersible zinc tablet (10 mg), daily; 5) Dispersible zinc tablet (10 mg), daily for two weeks at enrollment and 12 weeks; 6) Placebo powder, daily. Primary outcomes were incidence of diarrhea and change in length-for-age Z-score (LAZ) over the 24-week intervention period. Home visits were conducted twice weekly to assess diarrhea and other morbidity. Incidence and prevalence outcomes were compared among groups with Poisson regression; continuous outcomes were compared using analysis of covariance.
Results
2886 children were enrolled between February 2018 and July 2019. The mean incidence and prevalence of diarrhea among all participants was 1.21 episodes per 100 days and 3.76 days per 100 days, respectively. There were no differences in the incidence or prevalence of diarrhea across intervention groups. The decline in LAZ was slightly smaller among children in the daily HiZn LoFe MNP group vs. placebo powder group (P < 0.05).
Conclusions
The dose of zinc in MNPs as well as the duration and frequency of supplementation evaluated in this trial were not effective in reducing diarrhea; however, the daily HiZn LoFe MNP formulation offered modest improvements in linear growth among young children. NCT03406793.
