Numerous studies in developing countries have shown that routine oral zinc supplementation reduces the incidence of diarrheal disease, diarrhea-related mortality, and pneumonia. In a meta-analysis, zinc supplementation for three or more months in children younger than 5 years of age reduced episodes of diarrhea, respiratory tract infections, severe diarrhea or dysentery, persistent diarrhea, and lower respiratory tract infections or pneumonia. Two other meta-analyses that included several of the same trials found that zinc supplementation given to children between two and five years of age in developing countries reduced the incidence of clinically confirmed pneumonia by about 20 percent, and of diarrhea by 13 percent.
The doses of elemental zinc used in the studies included in these meta-analyses ranged from 15 to 140 mg/week. Trials in infants also suggest that zinc supplementation…
