The review found no eligible studies for this question.
The review found no eligible studies for this question.
Vitamin C and vitamin E showed no clear difference in any adverse effects of vitamin supplementation sufficient to stop… compared with placebo (moderate certainty).
Vitamin A supplementation probably leads to lower vitamin A deficiency compared with placebo or usual care (moderate certainty).
Vitamin D given to infants showed no clear difference in adverse effect (hypercalcaemia) compared with vitamin D given to lactating mothers (low certainty).
The intervention probably leads to lower all‐cause mortality in trials using vitamin D3 (cholecalciferol) ( (moderate certainty).
The intervention showed no clear difference in cardiovascular mortality in trials using vitamin D3… (low certainty).
The intervention probably leads to lower cancer mortality in trials using vitamin D3 (cholecalciferol) ( (moderate certainty).
The intervention probably leads to higher adverse events: nephrolithiasis in trials using vitamin D3 combined… (moderate certainty).
Vitamin A plus iron plus folate showed no clear difference in total fetal loss (including miscarriages or combined miscarriages… compared with iron plus folate (low certainty).
Vitamin A plus iron plus folate showed no clear difference in early or late miscarriage ‐ Vitamin A + iron + folate versus iron +… compared with iron plus folate (low certainty).
Vitamin A plus iron plus folate showed no clear difference in stillbirth ‐ Vitamin A + iron + folate versus iron + folate compared with iron plus folate (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).
Multivitamin plus iron plus folate showed no clear difference in early or late miscarriage ‐ Multivitamin + iron + folic acid versus… compared with iron plus folate (moderate certainty).
Multivitamin plus iron plus folate leads to lower stillbirth ‐ Multivitamin + iron + folic acid versus iron + folic acid compared with iron plus folate (high certainty).
Multivitamin plus iron plus folate showed no clear difference in total fetal loss (including miscarriages or combined miscarriages… compared with iron plus folate (high certainty).
It is very uncertain whether staple foods fortified with vitamin A changes subclinical vitamin A deficiency (serum/plasma retinol 70 μmol/L or… compared with same unfortified staple foods (very low certainty).
It is very uncertain whether staple foods fortified with vitamin A changes clinical vitamin A deficiency (defined as night blindness) compared with same unfortified staple foods (very low certainty).