2018 Jul 12

New search has been performed

Search updated.

2018 Jul 12

New citation required and conclusions have changed

Supplementation with vitamin D alone (22 trials in total, 13 new trials added in this update) during pregnancy probably reduces the risk of pre‐eclampsia, gestational diabetes and low birthweight.

Supplementation with vitamin D + calcium (9 trials in total, three new trials added in this update) during pregnancy probably reduces the risk of pre‐eclampsia but may increase the risk of preterm births.

Supplementation with vitamin D + other nutrients (1 trial trial added in this update) in pregnancy may make little or no difference in the risk of preterm birth or low birthweight.

In general, more data are needed to conclude about the risk of maternal adverse events.

2015 Jun 30

New citation required and conclusions have changed

Nine trials included for this update. The few trials that reported on the effects of vitamin D supplementation during pregnancy on low birthweight and preterm delivery suggest a lower risk on these outcomes with vitamin D in a single or continued dose. However, this result should be interpreted with caution due to the small number of trials and included pregnant women. Also, the quality of the evidence was low in most studies, with high heterogeneity.

2015 Jun 30

New search has been performed

Search and methods updated. We included a new comparison to assess the effects of vitamin D + calcium + other vitamins and minerals versus other vitamins and minerals (but no vitamin D + calcium). We also moved adverse effects to primary outcomes.

2012 May 10

Amended

Error in 'Plain language summary' corrected:
"Data from three trials involving 463 women show a trend for women who receive vitamin D supplementation during pregnancy to less frequently have a baby with a birthweight below 2500 grams than those women receiving no treatment or placebo".