Submitted to: Journal of Nutrition
Publication Type: Peer reviewed journal
Publication Acceptance Date: 2/22/2009
Publication Date: 3/25/2009
Publication URL: jn.nutrition.org/cgi/reprint/139/5/1022
Citation: Allen, L.H., Peerson, J.M., Olney, D.K. 2009. Provision of multiple rather than two or fewer micronutrients more effectively improves growth and other outcomes in micronutrient-deficient children and adults. Journal of Nutrition. 139: 1022-1030. Interpretive Summary: Where diets are poor, deficiencies of many micronutrients often occur simultaneously but programs often focus on improving intake of only one or few micronutrients. In recent years a number of investigators have compared the effects of providing multiple micronutrient (MMN) supplements or fortified foods to those of a control group given a placebo or a few micronutrients. The purpose of this analysis was compare the effects of providing MMN vs. no, one or two micronutrients, on growth, health and development of children, pregnancy outcome, nutritional status indicators, and HIV/AIDS mortality and morbidity. A pooled analysis of child growth and nutritional status outcomes revealed that MMNs improve length or height, weight, hemoglobin, serum zinc, serum retinol and motor development more than in controls, but do not increase hemoglobin more than iron alone. A published analysis concluded that MMN supplementation of pregnant women reduced risk of low birth weight, small-for-gestational-age and anemia. Evidence is accumulating that MMN supplements improve immune function and reduce morbidity and mortality in adults with HIV. Overall this analysis provides substantial evidence that MMN benefit health and development and should probably replace many programs that supply fewer micronutrients, although programmatic challenges still remain.
Technical Abstract: Micronutrient deficiencies such as vitamin A, iron, and zinc are prevalent and often coexist, but most micronutrient interventions in developing countries have provided only one or two micronutrients. In order to inform public policy, in this article we compare the relative benefits of supplying multiple micronutrients (MMN) vs. a control group (usually a placebo or one or two micronutrients) on growth, health and development of children, pregnancy outcome, nutritional status, and HIV/AIDS mortality and morbidity. Sufficient data were available to perform pooled analyses of the effects of MMN on child growth and nutritional status. Results for other outcomes are presented as published effect sizes (ES) when available. In children, MMN interventions improved growth (ES=0.16 for length or height and 0.20 for weight), some biochemical measures (ES for hemoglobin 0.39, serum zinc 0.28, serum retinol 0.41) and motor development. MMN did not increase hemoglobin more than iron alone. A Cochrane review reported that compared to =2 micronutrients or a placebo, MMN supplementation during pregnancy reduces relative risk of low birth weight (0.83), small-for-gestational age (0.92) and anemia (0.61). Evidence is accumulating that MMN supplementation improves CD4+ counts and HIV related morbidity and mortality in adults. The efficacy of MMN varies across trials, but overall there is substantial evidence that outcomes are better than when providing a placebo or only one or two micronutrients. The policy implications of these studies are discussed.