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
Frequency of leg cramps after treatment: never · treating leg cramps in pregnancy
1 finding from 1 review
Any adverse effects · 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
Low birthweight · Women receiving supplements in pregnancy
Any intermittent iron regimen (with or without other vitamins and… showed no clear difference in low birthweight (less than 2500 g) compared with daily regimen (with same vitamins and minerals)‐infant outcomes (low certainty).
1 finding from 1 review
Participants with at least some Side Effects · Women receiving supplements in pregnancy
It is very uncertain whether any intermittent iron regimen (with or without other vitamins and… changes side effects (any reported throughout intervention period) compared with daily regimen (with same vitamins and minerals)‐maternal outcomes (very low certainty).
1 finding from 1 review
Severe anaemia at any time during second and third trimester (Hb less than 70 g/L) · Women receiving supplements in pregnancy
1 finding from 1 review
Maternal clinical malaria or other infection in pregnancy · Women receiving supplements in pregnancy
Any intermittent iron regimen (with or without other vitamins and… led to lower maternal clinical malaria or other infection in pregnancy compared with daily regimen (with same vitamins and minerals)‐maternal outcomes; GRADE not reported.
1 finding from 1 review