The World Health Organization and multiple scientific studies say taking folic acid does not raise the risk of a miscarriage.
Social media posts, opens new tab suggested that folic acid was harmful to pregnant women and shared, opens new tab a screenshot of an article headline from the Daily Sceptic website that said, "Why is Britain About to Put a Medicine That Increases Miscarriages into Flour?"
The claim relates to the UK government's move to make adding folic acid to non-wholemeal wheat flour mandatory, opens new tab from December 2026.
Folic acid is a synthetic form of the B vitamin folate, which is found in asparagus and broccoli. It can be taken as pills or added to flour and cereals, and supplementation is typically advised before and during pregnancy to prevent birth defects in the brain and spine.
MISCARRIAGE RISK
The available evidence does not indicate that folic acid increases the risk of miscarriage, a World Health Organization spokesperson said in an email.
WHO,, opens new tab U.S. Centers for Disease Control and Prevention, opens new tab and the UK's Chief Medical Officers, opens new tab say folic acid can help reduce the risk of defects to the neural tube, which is the structure that later becomes the baby's brain and spinal cord.
Pregnancies with some neural tube defects, such as anencephaly, opens new tab, often end in miscarriages, according to the Cleveland Clinic, opens new tab.
Multiple scientific studies say folic acid either does not impact the risk of a miscarriage or reduces that risk.
The Cochrane Review scientific journal said, opens new tab in a 2015 review of five studies — involving a total of 7,391 women — that folic acid prevented neural tube defects but did not have a clear effect on other birth defects, including miscarriages.
A retrospective cohort study in China, published in The Lancet in 2001, said, opens new tab it found no evidence that daily consumption of 400 micrograms of folic acid before and during early pregnancy influenced women's risk for miscarriage.
One 2026 review, opens new tab and analysis published in the American Journal of Obstetrics & Gynecology Maternal-Fetal Medicine looked at three randomised controlled trials among more than 5,000 women – including women planning to conceive and not at increased miscarriage risk.
It concluded that higher doses of folic acid supplementation — 4 to 5 milligrams per day — were "associated with a statistically significant reduction in miscarriage risk".
DAILY SCEPTIC
The article, opens new tab in the Daily Sceptic, a website that challenges scientific consensus on global warming and COVID-19, questioned the claim that folic acid was beneficial, saying falsely that only one clinical trial, back in 1992, had examined the question in women who were not at increased miscarriage risk.
The study saw women planning a pregnancy given either a multivitamin supplement including folic acid or a trace element placebo. Out of 4,753 confirmed pregnancies, the study, opens new tab found six neural tube defects in the babies of women taking the placebo and none for those who took the multivitamin supplement with folic acid.
A report published two years later by the same authors looked at the pregnancy outcomes of those involved in the trial. It contained, opens new tab a table showing there were 374 fetal deaths (including 301 miscarriages) for those who took the multivitamin supplement with folic acid and 304 (including 251 miscarriages) among those who were given the placebo.
Of the 1994 finding, the Daily Sceptic article said, "the importance of this finding has been ignored while the six defects figure has been used to dictate policy globally".
However, the authors of the 1994 report explained their finding by pointing to the increased number of pregnancies in the group taking folic acid. Because there were more pregnancies and multiples in the folic acid group, the rates of miscarriage in both groups were essentially the same, they concluded.
The report said, opens new tab: "Periconceptional multivitamin supplementation increased fertility (higher rates of cumulative conceptions and multiple births), had no significant effect on the rate of different groups of fetal deaths, low birth weight and preterm birth in singletons."
The author of the Daily Sceptic article said she stood by her reporting based on the cited papers and subsequent research not cited in the article.
The Department of Health and Social Care did not respond to a request for comment.
VERDICT
Misleading. The World Health Organization and multiple scientific studies say taking folic acid does not have an impact on the risk of a miscarriage.
This article was produced by the Reuters Fact Check team. Read more about our fact-checking work.
