Vitamin A supplements for preventing mortality, illness, and blindness in children aged under 5: systematic review and meta-analysis

Vitamin A supplements for preventing mortality, illness, and blindness in children aged under 5: systematic review and meta-analysis

Vitamin A refers to a subclass of retinoic acids long understood to help regulate immune function and to reduce morbidity of infectious diseases. Vitamin A is required for normal functioning of the visual system, maintenance of cell function for growth, epithelial integrity, production of red blood cells, immunity, and reproduction. Different forms of vitamin A include β carotene, which is found in plants, and preformed vitamin A, which is found in animal sources. Vitamin A is an essential nutrient that cannot be synthesised so it must be obtained through diet.

Vitamin A deficiency increases vulnerability to a range of illnesses including diarrhoea, measles, and respiratory infections. These are leading causes of mortality among children in low and middle income countries, where risk of infection and risk of mortality can be compounded by coexisting undernutrition.

The objective of this study is to determine if vitamin A supplementation is associated with reductions in mortality and morbidity in children aged 6 months to 5 years.

The study finds that Vitamin A supplementation is associated with large reductions in mortality, morbidity, and vision problems in a range of settings, and these results cannot be explained by bias. Further placebo controlled trials of vitamin A supplementation in children between 6 and 59 months of age are not required. However, there is a need for further studies comparing different doses and delivery mechanisms (for example, fortification). Until other sources are available, vitamin A supplements should be given to all children at risk of deficiency, particularly in low and middle income countries.