EFFECTS OF TWO FORMS OF DAILY PREVENTIVE ZINC AND THERAPEUTIC ZINC SUPPLEMENTATION FOR DIARRHEA ON GROWTH AND ACQUISITION OF DEVELOPMENTAL MILESTONES IN RURAL LAOTIAN CHILDREN: A RANDOMIZED TRIAL

Background and objectives: Evidence is needed on the optimal strategy for delivering zinc to improve growth and other zinc-related functional health outcomes in children. In this double-blind, placebo-controlled, randomized trial, we determined the impact of providing daily preventive zinc tablets (7 mg/d), daily multiple micronutrient powder sachets (containing 10 mg zinc, 6 mg iron and 13 other micronutrients), therapeutic zinc supplements for diarrhea treatment (20 mg/d for 10 days) or daily placebo powder, on growth and acquisition of motor and language developmental milestones in young children in rural Lao PDR. Methods: 3433 children 6-23 months old at enrollment were randomized to one of four intervention groups and followed weekly for ~9 months. Weight and length were assessed at baseline and endline, 32-40 weeks later. Motor milestones (crawling, sitting without support, standing with assistance, standing alone, walking with assistance, walking alone, running, eating, drinking and waving) and language acquisition were assessed weekly by caregiver report and monthly by observation. We compared final height-for-age, weight-for-age, and weight-for-height z-scores, and stunting, underweight and wasting prevalence, and age of acquisition of developmental milestones among the 4 groups using linear or logistic regression (anthropometric outcomes) and cox proportional hazard models (milestone acquisition), controlling for age and baseline values. Intervention groups are still masked. Results: Groups were comparable regarding age, anthropometric scores and attained milestones at baseline. Mean age at baseline was 14.2 ± 5.1 mo; and there was a high prevalence of stunting (37.9%), underweight (26.0%) and wasting (7.9%). We observed a marginally significant treatment effect on the prevalence of final stunting (34.8-41.2% across the groups), wasting (3.8-6.6%) and underweight (22.3-24.9%). There were no between-group differences in final anthropometric indices. We observed a significant treatment effect on reported or observed onset of crawling, sitting without support, standing with assistance, standing alone and walking with assistance but not on other milestones. Conclusions: Endline stunting, wasting and underweight were marginally different and onset of crawling, sitting without support, standing with assistance, standing alone, and walking with assistance differed significantly by treatment group after ~9 months of supplementation. Specific pairwise dif