Zinc-fortified foods may be the most effective way of ensuring adequate growth for children, especially those in developing countries, American researchers have found.
A meta-analysis of 33 different studies carried out between 1976 and 2001 to measure the effects of zinc supplementation was published in a recent issue of the American Journal of Clinical Nutrition. The findings showed that zinc supplementation of infants and children produced positive growth responses in height and weight.
Individual studies of the effect of zinc supplementation on children's growth have yielded inconsistent results due to unpredictable factors such as the availability of zinc in the local diet and the pre-existing zinc status of the study subjects.
In order to provide a systematic qualitative review of findings regarding the efficacy of zinc supplementation, the researchers consolidated results from studies from countries around the world, based on a standard set of inclusion criteria. Thirteen of the studies were conducted in Latin America or the Caribbean, eight in Asia, eight in North America or Europe and four in Africa.
The study studied a number of children from birth up to the age of 10. Results showed that infants and children who were initially stunted or underweight experienced the greatest benefit from zinc supplements.
Zinc supplements significantly increased serum zinc concentrations, which has important public health implications because serum zinc increases are routinely used in field studies as a practical indicator that supplements have been delivered, consumed and absorbed by the recipients.
In an editorial published in the journal regarding the results of the analysis, it was noted that in poorer countries where dietary quality is uncertain, the nutritional needs of young children are unlikely to be met even though enough food is consumed to meet energy requirements. Providing zinc-fortified complementary foods in such circumstances may be the most cost-effective approach to assuring adequate growth for infants and children in developing countries.