Fewer than one in five women in England now take folic acid before pregnancy. This is down from one in four just five years ago.
Authors
- Danielle Schoenaker
Associate Professor of Preconception Health and Care, University of Southampton
- Keith Godfrey
Professor of Epidemiology and Human Development, University of Southampton
The decline is worrying because it could undermine the progress that has been made in recent years to prevent serious birth defects linked to low folic acid intake.
Although the UK government has mandated that from December 2026 all non-wholemeal wheat flour must be fortified with folic acid , the amount being added isn't enough to stop the ongoing need for folic acid supplements. As such, all women planning to become pregnant should still take a folic acid supplement daily when trying to get pregnant and during their first trimester.
Folic acid is the synthetic form of folate (also known as vitamin B9). It helps cells grow and divide.
In early pregnancy, folic acid supports the development of the neural tube, which becomes the baby's brain and spinal cord . If the tube does not close properly, babies can develop conditions such as spina bifida or anencephaly.
Spina bifida happens when a baby's spine and spinal cord do not fully develop, while anencephaly is a severe condition where major parts of the brain and skull are absent.
In England, it's estimated that some form of neural tube defect occurs in 12.5 per 100,000 births . Most of these conditions can be prevented if a woman has enough folate before becoming pregnant. Other factors, such as not getting enough vitamin B12 , may also play a role. Mild forms affect 5 to 10 million people.
Neural tube defects can also lead to pregnancy loss, death soon after birth or lifelong disability, with devastating impacts on families.
Because these conditions develop so early in pregnancy, taking a folic acid supplement before getting pregnant remains one of the most important ways to reduce the risk.
A widening gap
The decline in folic acid use before pregnancy is worrying for a number of reasons.
Uptake is already low in certain groups, with data showing supplement use is consistently lowest among Black and Asian women and those living in deprived areas .
Uptake has also fallen steeply in the north-east of England and remains well below the national average in the west midlands. These differences show folic acid supplement use is not simply individual choice.
Several factors influence uptake. Some women are not planning a pregnancy , while others do not know when folic acid is needed, believe a healthy diet is enough, or lack access to pre-pregnancy care.
Previous pregnancy experience does not necessarily help, either. Research suggests women who have been pregnant before are less likely to take folic acid during their next pregnancy compared to first-time mothers. Possible reasons for this include unplanned later pregnancies, competing childcare responsibilities and a lower sense of need after a prior healthy pregnancy. So knowledge is not enough.
It's currently not clear why supplement use has been declining overall. It may reflect a combination of limited and unequal access to timely pre-pregnancy advice or practical barriers such as cost and availability. It could also be due to confusion about whether flour fortification means supplements are no longer needed.
Why fortification isn't enough
The key challenge with folic acid is timing. The neural tube closes by about four weeks after conception , often before a woman knows she is pregnant.
As many pregnancies are unplanned , this means many women will not start supplements before the neural tube closes. Even those intending to become pregnant may miss this critical window if they do not receive timely advice.
So relying on supplements alone to prevent serious birth defects is not a good strategy.
Mandatory fortification is valuable because it does not depend on pregnancy planning. It safely raises folate levels across the population , including in women not taking supplements or who become pregnant unexpectedly.
Countries which have already introduced mandatory fortification - including the US, Canada, Chile and Australia - show how powerful this can be in preventing neural tube defects . For instance in Canada, where mandatory fortification was introduced in 1998, rates of spina bifida fell by 53% .
The new UK policy will add a low level of folic acid (0.25mg per 100g flour) to non-wholemeal wheat flour.
Although this new strategy is welcome, experts have already raised concerns that it will only prevent a small proportion of neural tube defects.
The government estimates that this strategy will reduce neural tube defects by around 20%, preventing about 200 cases each year. But this falls short of the reduction of between 25 and 50% seen in countries fully effective fortification levels .
The design of the UK scheme will also limit who benefits most. It covers only non-wholemeal wheat flour, excluding wholemeal flour, some imported products and many non-wheat flours that are important staples for some cultural and ethnic communities.
Preventing most neural tube defects requires high enough folate levels before pregnancy begins. Diet alone is unlikely to achieve this, and the proposed fortification level will provide only partial protection.
There's also a communication risk. If people hear that flour is being fortified, they may assume supplements are no longer needed. As England's chief medical officer , Chris Whitty, has said, fortification is a "simple and effective" way to reduce neural tube defects - but women who may become pregnant should still take a folic acid supplement before and during the first 12 weeks.
With folic acid supplement use already in decline, it's key that women are still made aware of the benefits of using supplements before pregnancy.
Adding folic acid to flour is a long-needed step towards population-wide health. But it is not enough. The aim will be to achieve a system that combines fully effective fortification with timely education, care and support before and between pregnancies, so every woman has the best possible protection against birth defects.
Danielle Schoenaker receives funding from the National Institute for Health and Care Research (NIHR) through an NIHR Advanced Fellowship (NIHR302955), the NIHR Biomedical Research Centre: Southampton (NIHR203319), and the NIHR Inequalities Challenge: Maternity Disparities Consortium (NIHR208377 and NIHR208324).
Keith Godfrey receives funding from the National Institute for Health and Care Research (NIHR) through the NIHR Biomedical Research Centre: Southampton (NIHR203319), and the NIHR Inequalities Challenge: Maternity Disparities Consortium (NIHR208377 and NIHR208324). He is affiliated with the UK Preconception Partnership, which advocates to support people with preparation for pregnancy and parenthood.
