Zinc Supplementation in Children: Evidence Summary and Recommendations

Zinc is an essential trace element required for growth, immune function, and epithelial integrity. Randomized trials and systematic reviews show that zinc supplementation in children—especially where zinc deficiency is common—produces modest but meaningful improvements in linear growth and weight gain, reduces duration and severity of acute diarrheal episodes and lowers the incidence of subsequent diarrhea, and may reduce all-cause mortality in certain high-risk groups. Evidence for benefit on neurocognitive outcomes is inconsistent. Zinc supplements are generally safe at recommended doses; vomiting is the most commonly reported adverse effect when used during acute diarrhea. Current clinical and public health guidance (including WHO) supports zinc use for the treatment of childhood diarrhea and considers preventive supplementation in settings with high prevalence of deficiency. Zinc plays multiple biological roles: enzyme cofactor, regulator of gene expression, and mediator of immune responses. Children in low- and middle-income countries (LMICs) are at particular risk of zinc insufficiency due to diets low in bioavailable zinc and higher burdens of infections that increase losses. Public health interest centers on two uses of zinc in children; therapeutic zinc during acute diarrheal illness and preventive (routine) zinc supplementation to improve growth, reduce infection risk, and lower mortality. Meta-analyses of RCTs report reduced all-cause mortality associated with zinc supplementation in some pooled analyses—effects appear strongest when doses of _x۰۰۰۲_۶۱۰ mg/day are used, and in trials with follow-up _x۰۰۰۲_۶۱ year and in low birth weight infants. Evidence is heterogeneous and context-dependent, but the potential mortality. Treatment of acute diarrhea (children ۶ months-۵ years): Provide oral zinc (commonly ۱۰ mg/day for infants ۶ months or ۲۰ mg/day for older infants & children for ۱۰-۱۴ days depending on guideline and formulation). Preventive supplementation (programmatic use): In populations with a high prevalence of zinc deficiency, routine preventive zinc (e.g., ۱۰ mg daily for several months or programmatic intermittent regimens used in trials) can be considered to reduce diarrheal morbidity and support growth. Program design should consider baseline zinc status, co-existing micronutrient programs (particularly iron), and monitoring.