Zinc supplementation may reduce the incidence of pneumonia by 41 per cent and that of diarrhoea by up to 25 per cent, say the Zinc Investigators’ Collaborative Group. Writing in the Journal of Pediatrics (1999;135:689), they report a pooled analysis of 10 trials (published and unpublished) in nine developing countries. The doses of zinc salts most commonly given were between 10 and 20mg daily for at least two weeks.
The overall reduction of diarrhoea prevalence was 25 per cent, with an 18 per cent reduction in incidence. The authors say that this compares with the reduction of 27 per cent achieved by improving water and sanitation. The reduction in incidence of pneumonia was 41 per cent, which, they say, is greater than that seen with any other preventive intervention for the illness.
The authors state that zinc deficiency, which is prevalent in young children in developing countries, is associated with decreased rates of immunocompetence and increased rates of serious infectious diseases. They conclude that the “substantial benefits” of zinc supplementation for prevention of pneumonia and diarrhoea suggest that it might be “an important means to improve child survival”. Improving the zinc status of developing country populations is essential, they say.