Vitamin D + calcium + other vitamins and minerals showed no clear difference in preterm birth (less than 37 weeks' gestation) compared with calcium + other vitamins and minerals (but no vitamin D) (low certainty).
Vitamin D + calcium + other vitamins and minerals showed no clear difference in low birthweight (less than 2500 g) compared with calcium + other vitamins and minerals (but no vitamin D) (low certainty).
It is very uncertain whether summary of findings table ‐ Vitamin B12 supplementation changes maternal anaemia compared with placebo/no vitamin B12 supplementation (very low certainty).
Summary of findings table ‐ Vitamin B12 supplementation showed no clear difference in low birthweight (< 2500 g) compared with placebo/no vitamin B12 supplementation (low certainty).
Summary of findings table ‐ Vitamin B12 supplementation showed no clear difference in preterm birth (< 37 weeks) compared with placebo/no vitamin B12 supplementation (low certainty).
The review found no eligible studies for this question.
Vitamin A alone showed no clear difference in maternal mortality compared with placebo or no treatment (high certainty).
Vitamin A alone showed no clear difference in perinatal mortality compared with placebo or no treatment (high certainty).
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 supplementation probably leads to lower pre‐eclampsia compared with placebo or no intervention (moderate certainty).
Vitamin D supplementation probably leads to lower gestational diabetes compared with placebo or no intervention (moderate certainty).
Vitamin D supplementation may leads to lower maternal adverse events: severe postpartum haemorrhage compared with placebo or no intervention (low certainty).
It is very uncertain whether vitamin D supplementation changes maternal adverse event: nephritic syndrome compared with placebo or no intervention (very low certainty).
Vitamin D supplementation showed no clear difference in preterm birth (less than 37 weeks' gestation) compared with placebo or no intervention (low certainty).