Maternal anaemia · pregnant women
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).
1 finding from 1 review
Miscarriage and spontaneous abortion · pregnant women
1 finding from 1 review
Low birthweight · pregnant women
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).
1 finding from 1 review
Preterm birth · pregnant women
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).
1 finding from 1 review
Child cognitive outcomes · pregnant women
1 finding from 1 review
Neural tube defects ‐ not reported · pregnant women
The review found no eligible studies for this question.
1 finding from 1 review
no estimate extracted
Studies not reported
No studies found
Maternal death · pregnant women
Vitamin A alone showed no clear difference in maternal mortality compared with placebo or no treatment (high certainty).
1 finding from 1 review
Perinatal mortality · pregnant women
Vitamin A alone showed no clear difference in perinatal mortality compared with placebo or no treatment (high certainty).
1 finding from 1 review
Maternal anaemia · pregnant women
Vitamin A alone probably leads to lower maternal anaemia compared with placebo or no treatment (moderate certainty).
1 finding from 1 review
Maternal infection · pregnant women
Vitamin A alone may leads to lower maternal clinical infection compared with placebo or no treatment (low certainty).
1 finding from 1 review
Preterm birth · pregnant women
Vitamin A alone showed no clear difference in preterm birth compared with placebo or no treatment (high certainty).
1 finding from 1 review
Total fetal loss (including miscarriages or combined miscarriages and stillbirths) · pregnant women
Vitamin C and vitamin E showed no clear difference in total fetal loss compared with placebo (high certainty).
1 finding from 1 review
Early or late miscarriage · pregnant women
Vitamin C and vitamin E showed no clear difference in early or late miscarriage compared with placebo (moderate certainty).
1 finding from 1 review
Stillbirth · pregnant women
Vitamin C and vitamin E showed no clear difference in stillbirth compared with placebo (moderate certainty).
1 finding from 1 review
Pre‐eclampsia · pregnant women and their infants..
Vitamin D supplementation probably leads to lower pre‐eclampsia compared with placebo or no intervention (moderate certainty).
1 finding from 1 review
Gestational diabetes · pregnant women and their infants..
Vitamin D supplementation probably leads to lower gestational diabetes compared with placebo or no intervention (moderate certainty).
1 finding from 1 review
Severe PPH (≥ 1000 mL) · pregnant women and their infants..
Vitamin D supplementation may leads to lower maternal adverse events: severe postpartum haemorrhage compared with placebo or no intervention (low certainty).
1 finding from 1 review
Maternal adverse event: nephritic syndrome · pregnant women and their infants..
It is very uncertain whether vitamin D supplementation changes maternal adverse event: nephritic syndrome compared with placebo or no intervention (very low certainty).
1 finding from 1 review
Maternal adverse event: hypercalcaemia · pregnant women and their infants..
1 finding from 1 review
Preterm birth · pregnant women and their infants..
Vitamin D supplementation showed no clear difference in preterm birth (less than 37 weeks' gestation) compared with placebo or no intervention (low certainty).
1 finding from 1 review