VITAMIN DEFICIENCY

Vitamin A deficiency is a common form of micronutrient malnutrition affecting 21.1% of preschool-age children and 5.6% of pregnant women worldwide. The published literature linking vitamin A interventions to causespecific child mortality due to measles, diarrhoea, malaria and other infectious diseases and to all-cause maternal mortality was comprehensively reviewed. Randomized controlled trial data of vitamin A interventions and survival were used to estimate the risk of mortality associated with vitamin A deficiency. The published relative risks were adjusted for the estimated prevalence of deficiency at study baseline. Summary relative risks were calculated from meta-analyses (for measles, diarrhoea, and other infectious disease causes of child mortality) or from single studies (malaria mortality among children and all-cause maternal mortality). The estimated relative risks associated with vitamin A deficiency in children were 1.86 (95% CI 1.32–2.59) for measles mortality, 2.15 (95% CI 1.83–2.58) for diarrhoea mortality, 1.78 (95% CI 1.43–2.19) for malaria mortality, 1.13 (95% CI 1.01–1.32) for other infectious disease mortality and 4.51 (95% CI 2.91–6.94) for all-cause maternal mortality. The available evidence suggests that nearly 8 deaths worldwide can be attributed to vitamin A deficiency among women and children. Approximately 20–24% of child mortality from measles, diarrhoea and malaria and 20% of all-cause maternal mortality can be attributed to this preventable condition. Africa and South-East Asia have the highest burden of disease. Chapter 4