Vitamin A supplementation probably leads to higher vomiting compared with placebo or usual care (moderate certainty).
Vitamin A supplementation leads to lower mortality due to diarrhoea compared with placebo or usual care (high certainty).
Vitamin A supplementation showed no clear difference in mortality due to measles compared with placebo or usual care (low certainty).
Vitamin A supplementation showed no clear difference in mortality due to LRTI compared with placebo or usual care (low certainty).
Vitamin A supplementation may leads to lower diarrhoea incidence Mean episodes per child per year compared with placebo or usual care (low certainty).
Vitamin A supplementation probably leads to lower measles incidence Mean episodes of measles per child per year compared with placebo or usual care (moderate certainty).
Vitamin A supplementation showed no clear difference in LRTI incidence Mean episodes per child per year compared with placebo or usual care (low certainty).
Vitamin A supplementation probably leads to lower bitot's spots incidence compared with placebo or usual care (moderate certainty).
Vitamin A supplementation probably leads to lower night blindness incidence compared with placebo or usual care (moderate certainty).
Vitamin C supplementation showed no clear difference in major cardiovascular event Physicians compared with placebo (low certainty).
It is very uncertain whether vitamin C supplementation changes cardiovascular mortality Physicians compared with placebo (very low certainty).
It is very uncertain whether vitamin C supplementation changes all‐cause mortality Physicians compared with placebo (very low certainty).
Vitamin C supplementation showed no clear difference in total myocardial infarction (fatal and non‐fatal) Physicians compared with placebo (low certainty).
Vitamin C supplementation showed no clear difference in total stroke (fatal and non‐fatal) Physicians compared with placebo (low certainty).
Vitamin C supplementation showed no clear difference in self‐reported CABG/PTCA Participant self‐reports compared with placebo (low certainty).
Vitamin C supplementation showed no clear difference in self‐reported angina Participant self‐reports compared with placebo (low certainty).
The review found no eligible studies for this question.
The review found no eligible studies for this question.