IMPACT OF ZINC SUPPLEMENTATION ON RESPIRATORY AND GASTROINTESTINAL INFECTIONS: A DOUBLE-BLIND, RANDOMIZED TRIAL AMONG URBAN IRANIAN SCHOOLCHILDREN

INTRODUCTION: In addition to inhibiting growth, mild zinc deficiency is probably associated with reduced resistance to infection in children, but it has been difficult to establish this link; however, children with severe zinc deficiency have been found to be at increased risk for diarrhea and respiratory diseases. OBJECTIVE: The aim of this study was to evaluate the roles of zinc supplementation in the episodes of respiratory and gastrointestinal infections in children. METHODS: This study was a randomized, double-blind, placebo-controlled trial of 90 children (50 boys and 40 girls aged 7–12 years) who were underweight or had stunted growth. They were supplemented with 10 mg of zinc or placebo on school days for 6 months. Episodes of respiratory and gastrointestinal infections were recorded monthly. RESULTS: At the end of this study, significant effects of zinc supplementation on the decreased number of episodes of respiratory and gastrointestinal infections were seen during the full 6 months. CONCLUSIONS: On the basis of this study, zinc supplementation decreased the number of episodes of respiratory and gastrointestinal infections in schoolchildren who were underweight or had stunted growth.