Vitamin A supplementation and child mortality. A meta-analysis

Abstract

<h3>Objective.</h3> —A two-part meta-analysis of studies examining the relationship of vitamin A supplementation and child mortality. <h3>Data Sources.</h3> —We identified studies by searching the MEDLARS database from 1966 through 1992 and by scanning<i>Current Contents</i>and bibliographies of pertinent articles. <h3>Study Selection.</h3> —All 12 vitamin A controlled trials with data on mortality identified in the search were used in the analysis. <h3>Data Extraction.</h3> —Data were independently extracted by two investigators who also assessed the quality of each study using a previously described method. <h3>Data Synthesis.</h3> —We formally tested for heterogeneity across studies. We pooled studies using the Mantel-Haenszel and the DerSimonian and Laird methods and adjusted for the effect of cluster assignment of treatment groups in community-based studies. Vitamin A supplementation to hospitalized measles patients was highly protective against mortality (DerSimonian and Laird odds ratio, 0.39; 95% confidence interval, 0.22 to 0.66;<i>P</i>=.0004) (part 1 of the meta-analysis). Supplementation was also protective against overall mortality in community-based studies (DerSimonian and Laird odds ratio, 0.70; clustering-adjusted 95% confidence interval, 0.56 to 0.87;<i>P</i>=.001) (part 2 of the meta-analysis). <h3>Conclusions.</h3> —Vitamin A supplements are associated with a significant reduction in mortality when given periodically to children at the community level. Factors that affect the bioavailability of large doses of vitamin A need to be studied further. Vitamin A supplements should be given to all measles patients in developing countries whether or not they have symptoms of vitamin A deficiency. (<i>JAMA</i>. 1993;269:898-903)