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).
Vitamin D supplementation probably leads to lower low birthweight (less than 2500 g) compared with placebo or no intervention (moderate certainty).
The review found no eligible studies for this question.
Vitamin D + calcium supplementation may leads to higher preterm birth (less than 37 weeks' gestation) compared with placebo or no intervention (low certainty).
It is very uncertain whether vitamin D + calcium supplementation changes low birthweight (less than 2500 g) compared with placebo or no intervention (very low certainty).
Vitamin D + calcium supplementation probably leads to lower pre‐eclampsia compared with placebo or no intervention (moderate certainty).
It is very uncertain whether vitamin D + calcium supplementation changes gestational diabetes compared with placebo or no intervention (very low certainty).
Vitamin A supplementation probably leads to lower vitamin A deficiency compared with placebo or usual care (moderate certainty).
It is very uncertain whether summary of findings table ‐ Vitamin B12 supplementation changes maternal vitamin B12 deficiency compared with placebo/no vitamin B12 supplementation (very low certainty).
Neonatal vitamin A supplementation showed no clear difference in vitamin A deficiency (serum retinol < 0.70 micromol/L) at 6 weeks of… compared with control (high certainty).
It is very uncertain whether high-dose vitamin D3 supplementation during pregnancy (2400 IU/day… changes caries presence in primary teeth compared with low-dose (standard) vitamin D supplementation as recommended in… (very low certainty).
The review found no eligible studies for this question.
Any vitamin E supplementation showed no clear difference in stillbirth compared with placebo, no placebo or other supplements (moderate certainty).
Any vitamin E supplementation showed no clear difference in preterm birth (less than 37 weeks' gestation) compared with placebo, no placebo or other supplements (high certainty).
Any vitamin E supplementation showed no clear difference in clinical pre‐eclampsia (random‐effects model) compared with placebo, no placebo or other supplements (moderate certainty).