Folic acid during pregnancy and preeclampsia risk
What it found
In a study of 10,041 pregnant women in China, those who took folic acid supplements had a lower risk of preeclampsia.
Higher folate from food was linked to lower risk of severe preeclampsia only.
What they found
Studies in people
Supplement use and preeclampsia
Women who took folic acid supplements had a lower risk of preeclampsia compared with those who did not. The authors report this as a reduced risk.
Duration of use
Among women who took supplements only during pregnancy, longer use was linked to lower risk. No such pattern was seen for overall duration of use.
Mild and severe preeclampsia
The lower risk with supplements was similar for mild and severe preeclampsia, but the link was statistically significant only for mild preeclampsia.
Early and late onset
The lower risk with supplements was similar for early-onset and late-onset preeclampsia, but the link was statistically significant only for late-onset preeclampsia.
Folate from food
Higher dietary folate intake during pregnancy was linked to lower risk of severe preeclampsia, but not mild preeclampsia. No overall link was found between dietary folate and preeclampsia risk.
What the authors conclude
“Our study results suggest that folic acid supplementation and higher dietary folate intake during pregnancy reduce the risk of preeclampsia.”
Also in their conclusions
- They conclude that folic acid supplementation and higher dietary folate intake during pregnancy reduce the risk of preeclampsia.
- They say future studies are needed to confirm these associations and to identify women who would benefit most from folic acid supplementation.
How it was done
Folic acid has been suggested to reduce the risk of preeclampsia, but results from previous studies have been inconsistent. The authors wanted to investigate whether folic acid supplements and dietary folate before and during pregnancy reduce the risk.
They followed 10,041 pregnant women who gave birth at a hospital in Lanzhou, China, between 2010 and 2012. Women were interviewed after delivery about supplement use and diet, and their medical records were used to identify preeclampsia.
What it can’t tell you
- This study followed women over time and cannot prove that folic acid directly causes the lower risk of preeclampsia.
- The study relied on women remembering their supplement use and diet, which may not be exact.
- The results are from one hospital in China and may not apply to all pregnant women.
Who paid
- Funding
- Funded by NICHD NIH HHS (from the PubMed record).
- Authors work at
- Gansu Provincial Maternity and Child Care Hospital, China; Yale University, USA; Shanxi Medical University, China
The paper
- Title
- Folic acid supplementation and dietary folate intake, and risk of preeclampsia
- Type
- Study
- Evidence
- Studies in people
- Summarised from
- Full text
- Cite
- Wang Y, Zhao N, Qiu J, et al (2015). Folic acid supplementation and dietary folate intake, and risk of preeclampsia. European journal of clinical nutrition. doi:10.1038/ejcn.2014.295Free full textPubMed 25626412DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error