Vitamin A deficiency and attributable mortality among under-5-year-olds.

Reported are estimates of the prevalence in developing countries of physiologically significant vitamin A deficiency and the number of attributable deaths. The WHO classification of countries by the severity and extent of xerophthalmia was used to categorize developing countries by likely risk of subclinical vitamin A deficiency. Using vital statistics compiled by UNICEF, we derived population figures and mortality rates for under-5-year-olds. The findings of vitamin A supplementation trials were applied to populations at-risk of endemic vitamin A deficiency to estimate the potential impact of improved vitamin A nutriture in reducing mortality during preschool years. Worldwide, over 124 million children are estimated to be vitamin A deficient. Improved vitamin A nutriture would be expected to prevent approximately 1-2 million deaths annually among children aged 1-4 years. An additional 0.25-0.5 million deaths may be averted if improved vitamin A nutriture can be achieved during the latter half of infancy. Improved vitamin A nutriture alone could prevent 1.3-2.5 million of the nearly 8 million late infancy and preschool-age child deaths that occur each year in the highest-risk developing countries.