This review, conducted by several American and Canadian research institutes, gives an overview of studies investigating the effects of vitamin A on general morbidity and mortality in children aged between 6 and 59 months in low- and middle-income countries. The review shows that vitamin A significantly reduces general morbidity and mortality as an underlying cause of vitamin A deficiency. For example, all-cause mortality, including mortality resulting from diarrhea, was reduced by 12%. Moreover, vitamin A supplementation significantly reduced the incidence and severity of diarrhea and measles. More details can be found in the review.
Imdad et al.