Giving children in Nepal who are zinc-deficient zinc supplementation makes to significant difference to their overall mortality. Toddlers aged 12-35 months receive a very slight, non-statistically significant benefit, according to an article in The Lancet, this week’s issue.
Malnutrition, including micronutrient deficiency, is the largest risk factor for child mortality in poor and middle income nations, according to the WHO Global Burden of disease project. The most common micronutrient deficiency for under 5s in developing countries is zinc deficiency.
Professor James Tielsch, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA and team carried out a study involving more than 40,000 children in Nepal, aged 1-35 months. Half the children were given zinc supplementation, 10mg per day, while the rest received a placebo. They were all followed up for at least twelve months. The trial studied mortality as the primary outcome. The researchers also monitored for diarrhea and acute respiratory infections, both linked to zinc deficiency.
The researchers report that they found no significant differences between the mortality rates within the placebo group and the zinc supplement group, including babies under 12 months of age from either group. A 20% lower mortality rate for those over 12 months in the zinc supplement group, compared to the placebo group, is not statistically significant, say the researchers. The incidence and duration of diarrhea, persistent diarrhea, dysentery, and acute lower respiratory functions was the same in the two groups.
The authors do, however, add that children with specific histories of malnutrition or morbidity could benefit from zinc supplementation. If they look at this study, and other previous studies, there are indications the zinc supplementation protect children over one year of age to some extent.
“However, whether improvements in population zinc status via universal routine supplementation are feasible remains to be shown. Further research on the optimum dose for reduction in morbid outcomes in various settings is needed before large-scale implementation of universal supplementation programs is justified,” they conclude.
“Zinc supplementation seems to have the potential to be an important intervention for the reduction of child mortality in low-income countries…additional evidence is needed if we want to clarify the real size of the effect, especially in regions without malaria, and to decide whether to supplement all children or those at high-risk only,” Dr Marzia Lazzerini, Institute of Child Health, IRCCS Burlo Garofolo, Trieste, Italy writes in an accompanying Comment.
Written by: Christian Nordqvist