Vitamin A: Deficiency and Interventions

Vitamin A (VA) deficiency causes xerophthalmia and increases risks of infant, child and, in some settings, maternal mortality. Night blindness, a symptom of deficiency, is readily detected in children and women in relation to pregnancy. Epidemiologic studies reveal inadequate breast and complementary feeding, and a household diet inadequate in preformed or carotenoid precursors of VA, as underlying causes of VA deficiency in children, exacerbated by infection. Prevention can be achieved through VA supplementation, food fortification, and a mix of dietary approaches that include gardening, nutrition education, and other means, including biofortification in the future. Periodic VA supplementation has proven effective and affordable in preventing xerophthalmia, reducing mortality, and attenuating hearing loss from infections in children. Fortification of staple food items, as well as home-based fortification with nutrient powders, offer promise of sustained and effective prevention. Assuring dietary diversity is most attractive, but lacks data on how best to proceed. Biofortification of staple crops is emerging as a promising approach to VA deficiency prevention.