Vitamin A deficiency is common in low-income countries. Vitamin A supplementation to children above 6 months of age reduces all-cause mortality with 23 % to 30 %. Studies on vitamin A supplementation in infants younger than 6 months of age have reported inconsistent effects on mortality. Studies providing supplementation between 1 and 5 months of age have found no effect or even a negative effect. However, the only two studies of supplementation at birth, both conducted in Asia, showed substantial significant reductions in infant all-cause mortality.