Controlled Zinc Supplementation for Malnourished School Boys: A Pilot Experiment

Abstract

Sixty malnourished boys from a rural area in Iran, whose height was below the 3rd percentile of the Iowa growth standards, were divided into three groups matched for age. These groups were given supplements consisting of placebo, iron, or zinc in capsule form for 5 months. No supplement was given for 7 months and then there was a second 5-month period of supplementation. The latter supplement consisted of placebo for the first group, all essential nutrients except zinc for the second group, and all essential nutrients including zinc for the third group. Statistical evaluations were made only for the boys aged 12-14 years because these comprised uniform groups in respect to expected puberty and were uniform in numbers. Parameters compared among the three groups were changes in height, weight, bone development, and sexual maturation. Although there were trends of greater development toward normal for their age in height, weight, and bone growth in the zinc-supplemented group, not all of these changes were statistically significant. However, the zinc-supplemented group of 12-to 14-year olds developed sexually at a greater rate than the placebo or iron-supplemented groups. This increase was statistically highly significant. These results provide additional strength to the hypothesis that zinc dieficiency is an important etiologic factor in growth retardation and delayed sexual maturation among rural adolescent boys in Iran.