Folic acid: The case to rethink the UK’s food fortification plans

“The importance of folic acid has been known for some 30 years, enough time for a whole generation to be having children of their own,” says Gareth Nye, endocrinology lead at the Physiological Society.

Folic acid supplementation in pregnant women can prevent neural tube defects (NTDs) from developing in the fetus. NTDs are a group of disorders in which the top portion of the brain is missing. They can lead to miscarriages, stillbirths, or neonatal deaths. One NTD, spina bifida, leads to a lifetime of hospital admissions and can be paralysing from the waist down.

Women can get folic acid from their diet, but current diets are unlikely to meet recommended levels. This is because of low intakes of whole foods that contain folic acid, particularly among more disadvantaged groups that face systemic barriers to eating well, such as access to different food types or cost.

In 1991, a randomised trial showed that a supplement of four milligrams of folic acid a day started before pregnancy could prevent an estimated 83% of NTDs.1 The timing of the supplement is crucial because the neural tube in a healthy fetus closes within a few weeks of conception.

As a result of the finding, the UK Scientific Advisory Committee on Nutrition (SACN) in 2006 began to advise pregnant women and those trying to become pregnant to take folic acid supplements—a policy that Nye says has “undoubtedly changed the outcomes for millions of pregnancies” since being adopted.