(HealthDay News)  For children aged 6 months to 12 years, zinc supplementation has no clear effect on mortality but seems to reduce diarrhea morbidity, according to a review published online May 15 in The Cochrane Library.

Evan Mayo-Wilson, DPhil, from the Johns Hopkins University Bloomberg School of Public Health in Baltimore, and colleagues examined the effects of zinc supplementation on preventing mortality and morbidity, and on promoting growth in young children. Eighty randomized controlled trials of preventive zinc supplementation involving 205,401 children aged 6 months to 12 years of age were included.

The researchers found that zinc supplementation correlated with risk ratios (RRs) of 0.95 for all-cause mortality (95% confidence interval [CI], 0.86–1.05); 0.95 for cause-specific mortality due to diarrhea (95% CI, 0.69–1.31); 0.86 for lower respiratory tract infection (LRTI; 95% CI, 0.64–1.15); and 0.90 for malaria (95% CI, 0.77–1.06). Diarrhea morbidity was reduced with supplementation, including incidence of all-cause diarrhea (RR, 0.87; 95% CI, 0.85–0.89); the results for LRTI and malaria were imprecise. Moderate-quality evidence indicated a very small improvement in height with supplementation (standardized mean difference, −0.09). There was an increased risk of at least one vomiting episode associated with supplementation (RR, 1.29; 95% CI, 1.14–1.46)

“The effect of preventive zinc supplementation on all-cause mortality was not statistically significant, but these results are consistent with a small reduction in mortality,” the authors write. “In our opinion, the benefits of preventive zinc supplementation outweigh the harms in areas where the risk of zinc deficiency is relatively high. Further research should determine optimal intervention characteristics such as supplement dose.”

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