Effects of Daily Zinc, Daily Multiple Micronutrient Powder, or Therapeutic Zinc Supplementation for Diarrhea Prevention on Physical Growth, Anemia, and Micronutrient Status in Rural Laotian Children: A Randomized Controlled Trial

To evaluate the optimal zinc supplementation strategy for improving growth and hematologic and micronutrient status in young Laotian children. In total, 3407 children aged 6-23 months were randomized to receive either daily preventive zinc tablets (7 mg/d), high-zinc, low-iron micronutrient powder (10 mg/d zinc, 6 mg/d iron, and 13 other micronutrients), therapeutic zinc supplementation for diarrhea (20 mg/d for 10 days per episode), or daily placebo powder; all were followed for ~9 months. Anthropometry, hemoglobin, zinc, and iron status were assessed at baseline and endline. Analyses were by intention-to-treat, using linear and modified Poisson regression. At baseline, mean (±SD) age was 14.2 ± 5.1 months and stunting and anemia prevalence were 37.9% and 55.6%, respectively. At endline, zinc deficiency in the preventive zinc (50.7%) and micronutrient powder (59.1%) groups were significantly lower than in the therapeutic zinc (79.2%) and control groups (78.6%; P