Effect of vitamin A supplementation on the growth of young children in northern Ghana.

Abstract

The effect of prophylactic vitamin A supplementation on child growth was studied in two randomized, placebo-controlled trials carried out in adjacent areas of northern Ghana between 1989 and 1991. In the Health Study, the midupper arm circumference (MUAC) and weight of the ≃ 1500 children (aged 6- 59 mo) in the trial were measured every 4 wk for up to 52 wk. In addition, MUAC, weight, and height were measured at each of the four potential vitamin A or placebo dosing times, which were at 4-mo intervals. In the Survival Study, MUAC and weight were measured at 4-mo intervals at each of seven dosing rounds in the ≃15 000 children currently in the trial. Overall, there were > 90 000 observations of weight and MUAC in > 25 000 children, and 3347 observations of length/height in 1546 children. Within each study, the mean monthly weight, MUAC, and gains in length/height in each treatment group were compared by using multilevel modeling. There were no significant differences in either MUAC or gains in length/height. The only significant difference in weight gain was in the Survival Study: children in the vitamin A supplemented group who were ≥ 36 mo of age had a mean weight gain that was 3 g lower per month (95% CI: 0.4, 5.0, P = 0.02) than that in the placebo group; a difference that was unlikely to be functionally important in this age group. Vitamin A supplementation did not lead to any increased growth in this population of young children, in whom supplementation reduced mortality and severe morbidity substantially.