Zinc during and in convalescence from diarrhea has no demonstrable effect on subsequent morbidity and anthropometric status among infants <6 mo of age.

Randomized, placebo-controlled trial in very young infants 1-5 months of age with acute diarrhea enrolled in low-income districts of Addis Ababa, Ethiopia; Karachi, Pakistan; and New Delhi, India. For the zinc group, 538 participants were randomized, with a 538:536 allocation ratio versus placebo.

The active regimen was zinc sulfate 10 mg/day as a dispersible oral tablet, given once daily for 14 days during and after an acute diarrhea episode, compared with placebo.

Zinc did not improve subsequent morbidity or growth compared with placebo, and infants receiving zinc had more days of diarrhea. Over 8 weeks of follow-up, there were no significant differences in change in WAZ, LAZ, or WLZ, and morbidity outcomes were also null: diarrhea incidence rate RR = 1.02; days of diarrhea RR = 1.22; any respiratory infection or pneumonia RR = 1.00; pneumonia RR = 1.04. The authors concluded that young infants do not appear to benefit from this short course of zinc, unlike older children.

The intervention was brief, with only 14 days of zinc and 8 weeks of follow-up. Generalizability is limited to very young infants with acute diarrhea in low-income settings, and the report provides limited detail for some anthropometric measurements and baseline dietary assessment.