Zinc Supplementation in the Management of Acute Diarrhea in High-Income Countries – A Systematic Evaluation and Meta-Analysis

The World Health Organisation (WHO) and the United Nations International Children’s Emergency Fund (UNICEF) recommend zinc supplementation for children with diarrhea. However, Low and Middle-Income Countries (LMICs) conducted the majority of the studies supporting this recommendation. Although the mortality rate of acute diarrhea in developed countries is low, diarrhea leads to a high number of clinical care and hospital admissions, which represents a significant economic burden. This systematic review assessed the therapeutic benefits of zinc supplementation in the treatment of acute diarrhea in children living in high-income countries. We conducted a literature search on the Medline, Embase, Cochrane, and SciELO databases to find published randomised controlled trials on zinc supplementation and acute diarrhea in children residing in developed countries. We conducted a systematic literature search of the databases, uncovered 609 titles, and included 3 trials, totalling 620 treated children with acute diarrhea, after reviewing abstracts and full manuscripts for inclusion and exclusion criteria. Two studies showed that zinc did not interfere with the duration of diarrhea. According to the Cochrane Risk of Bias RoB 2, risk was considered low in two studies and some concerns in another. There was no statistically significant reduction in the mean RR for the occurrence of diarrheal episodes after 7 days of zinc supplement administration (0.4% vs. 0.6%; RR 0.73; 95% CI 0.28-1.92; p=0.53; I2=16%). Zinc supplementation did not reduce the duration of acute diarrhea among children living in developed countries. Keywords Acute diarrhea; Zinc supplementation; Children; High-income countries