The Effect of Daily Zinc Supplementation on Prevention of Diarrhea and Acute Respiratory Infections among Children Less Than Five Years: A Randomized Controlled Trial

Abstract

Background: Infants and children below five years of age are the most vulnerable group to zinc deficiency. Hence, they present with clinical manifestations associated with zinc deficiency such as increased incidence of common infectious diseases like diarrhea and pneumonia. Objective: The goal of this study is to determine the level of blood zinc in children aged 6 months to less than 5 years old, and to assess the effect of 4 months of daily zinc supplements on the incidence and the severity of diarrheal morbidity and acute respiratory infection. Subjects and Methods: A randomized controlled trial study was conducted in Pediatric Outpatient Clinic in Ain Shams University Hospital on 140 children less than five years. Random assignment of the sampled children to group receiving zinc (70 children) or group receiving placebo (70 children) was done. A questionnaire containing questions about occurrence of diarrhea and acute respiratory infection was used during follow up. Serum zinc at baseline was measured. Results: The mean age was 25.26 ± 15.7 months. Mean of serum zinc was 51.08µg/dl, with 70% of the children had low baseline serum zinc level. Cumulative incidence of diarrhea, number of diarrheal episodes per child and occurrence of severe diarrhea decreased significantly in zinc group (P <o.o5). Risk ratio was found to be 0.79, 95% CI: 0.64 to 0.97 for diarrhea. Cumulative incidence of acute respiratory infection also decreased significantly in zinc group (P <o.o5). Risk ratio was found to be 0.97, 95% CI: 0.89 to 1.05 for acute respiratory infection. Conclusion: Incidence of diarrhea and acute respiratory infection and diarrheal severity reduced in children received zinc daily for four months. Recommendations: Prompt measures to improve zinc status of deficient children are warranted, together with developing a standard by which zinc supplementation can be administered in different conditions. This trial was registered at www.clinicaltrials.gov as NCT05002101