Background: Zinc deficiency is now widely recognized as a leading risk factor for morbidity and mortality and is estimated to be responsible for approximately 800,000 excess deaths annually among children under 5 years of age.
Objective: To evaluate the impact of zinc supplementation as an adjunct in the treatment of diarrhea, pneumonia, malaria, and tuberculosis in children under 5 years of age.
Methods: A comprehensive literature search of electronic databases to identify randomized, controlled trials on the topic was undertaken in January 2008. Eligible studies identified on search were reviewed by the authors and data extraction was done. Statistical analyses were performed with the use of Review Manager software.
Results: Current analysis of the adjunctive therapeutic benefit of zinc in acute diarrhea corroborates existing reviews and provides evidence of reduction in the duration of acute diarrhea by 0.5 day (p = .002) in children under 5 years of age. However, zinc supplementation is found to have no beneficial impact in infants under 6 months of age. A beneficial effect of zinc as an adjunctive treatment is also found in persistent diarrhea, the duration of which is reduced by 0.68 day (p < .0001). Evidence of the benefit of zinc supplementation in pneumonia and malaria is insufficient, whereas no studies are available in children with tuberculosis.
Conclusions: The existing literature provides evidence of a beneficial effect of therapeutic zinc supplementation in the reduction of the duration of acute and persistent diarrhea. However, evidence for its impact on pneumonia, malaria, and tuberculosis in children under 5 years of age is insufficient and needs further evaluation.