Vitamin A alone probably leads to lower maternal anaemia compared with placebo or no treatment (moderate certainty).
Vitamin A alone may leads to lower maternal clinical infection compared with placebo or no treatment (low certainty).
Vitamin A alone showed no clear difference in preterm birth compared with placebo or no treatment (high certainty).
Vitamin D given to infants may leads to lower vitamin D insufficiency: 25‐OH vitamin D < 50 nmol/L compared with placebo or no treatment (low certainty).
It is very uncertain whether vitamin D given to infants changes vitamin D deficiency: 25‐OH vitamin D < 30 nmol/L compared with placebo or no treatment (very low certainty).
Vitamin D given to lactating mothers may leads to lower vitamin D insufficiency: 25‐OH vitamin D < 50 nmol/L compared with placebo or no treatment (low certainty).
Vitamin D given to lactating mothers may leads to lower vitamin D deficiency: 25‐OH vitamin D < 30 nmol/L compared with placebo or no treatment (low certainty).
Supplemental vitamin A showed no clear difference in neonatal death compared with no supplementation (moderate certainty).
Supplemental vitamin A showed no clear difference in chronic lung disease (oxygen use at 28 days in survivors) compared with no supplementation (moderate certainty).
Supplemental vitamin A probably leads to lower death or chronic lung disease (oxygen use at 28 days) compared with no supplementation (moderate certainty).
Supplemental vitamin A showed no clear difference in death before 36 weeks' postmenstrual age compared with no supplementation (moderate certainty).
Supplemental vitamin A showed no clear difference in neurodevelopmental impairment at 18 to 22 months compared with no supplementation (low certainty).
Vitamin A supplementation leads to lower all‐cause mortality compared with placebo or usual care (high certainty).
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).