Objective: To study the effect of 2 weeks of prophylactic zinc supplementation on incidence and duration of acute respiratory infections.
Design: Randomized double blind controlled trial.
Setting: Community based; urban resettlement area in North-East Delhi, India.
Participants: 272 children aged 6-11 months with acute respiratory infections. Children receiving zinc supplement within the past 3 months, severely malnourished, immuno-deficient, on steroid therapy, with severe illness requiring hospitalization, or children of families likely to migrate from the study area were excluded.
Intervention: Placebo (syrup base) or zinc (20 mg/5 mL elemental zinc as zinc sulfate) orally given for a period of 2 weeks.
Main outcome measure(s): Incidence, type and duration of acute respiratory infections, and adverse effects.
Results: No effect on incidence of acute respiratory infections was noted. A decrease of 15% (0.78-0.94) in days and 12% (0.78-0.94) in duration of episode in acute respiratory infections was observed. Incidence of acute lower respiratory infections decreased by 62% (0.26-0.36) and the effect remained for full five months of follow up. There were no drop outs due to side effects.
Conclusions: Prophylactic zinc supplementation for two weeks may reduce the morbidity due to acute lower respiratory infections but not overall rate of acute respiratory infections in infants aged 6-11 months in similar populations.