A Cochrane review [Abstract] 1 included 40 studies with a total of 9276 820 subjects assessing supplementation with any vitamin(s) starting prior to 20 weeks' gestation and reporting at least one primary outcome. 8 trials were cluster randomised and contributed data for 217 726 women. No difference was seen between women taking any vitamins compared with controls for total fetal loss, early or late miscarriage or stillbirth and most of the other primary outcomes, using fixed-effect models.
Primary/Secondary Keywords