Zinc is an important micronutrient for humans and is necessary for protein synthesis, cell growth, and differentiation. Severe zinc deficiency can result in slower cognitive, physical and sexual growth. It can cause skin disorders, reduce immunity, increase prevalence of acute diseases in infants and children and can also contribute to childhood stunting. 17.3% of the world population is at risk of inadequate zinc intake. This nutritional impairment can increase the risk of diarrhoea and pneumonia by 20%. It can also lead to global loss of more than 16 million disability-adjusted life years in children < 5 years of age.

The objective of this analysis is to assess the effectiveness of zinc supplementation for the growth, decrease in mortality, and the prevention of infections in infants less than 6 months of age. Eight studies with 85,629 infants were involved and 5 studies were meta-analysed. Out of them, four studies compared zinc with placebo, and one study compared zinc plus riboflavin versus riboflavin. Certain growth consequences after six months of intervention were positively affected by zinc supplementation as compared to placebo. A single study has reported no difference in the prevalence of diarrhoea and lower respiratory tract infection with zinc supplementation. Also, no effect was seen in mortality in children < 12 months. Zinc plus riboflavin was compared to riboflavin only and significant improvement was detected in the prevalence of wasting at 24 months, but significant worsening of occurrence of stunting was present at 21 months.

The author concluded that there was a significant positive impact of zinc supplementation on Weight for Age Z-scores and Weight-for-Length Z-score after six months of intervention in infants as compared to placebo. A combined supplement of zinc and riboflavin as compared to riboflavin alone showed a significant reduction in wasting at 24 months, but negatively affected stunting at 21 months.

Source: Lassi ZS, Kurji J, Oliveira CS, Moin A, Bhutta ZA. Zinc supplementation for the promotion of growth and prevention of infections in infants less than six months of age. Cochrane Database Syst Rev. 2020 Apr 8;4(4):CD010205. doi: 10.1002/14651858.CD010205.pub2. PMID: 32266964; PMCID: PMC7140593.