Researchers have been awarded £1.9 million from the Medical Research Council (MRC) to evaluate the impact of the UK's mandatory folic acid fortification policy on maternal and child health.
The three-year study, led by King's College London and delivered in partnership with the University of Cambridge, the University of Edinburgh, Queen's University Belfast and the Born in Bradford cohort, will assess how the fortification of non-wholemeal wheat flour with folic acid affects maternal and infant health across the UK.
Folate (vitamin B9) is vital in early pregnancy and helps to prevent serious birth defects of the brain and spine, known as neural tube defects, including spina bifida. For women trying to conceive, the NHS recommends taking a folic acid supplement every day before pregnancy and up until 12 weeks of pregnancy.
However, some pregnancies are unplanned, and not all women are aware of the recommendations to take a folic acid supplement. To address this, in 2024 the UK government introduced new legislation, making it mandatory for millers and flour producers to add folic acid to non-wholemeal wheat flour during production from the end of 2026. This public health measure is expected to reduce neural tube defects by around 20 per cent.
This new study will provide UK-specific evidence on whether adding folic acid to flour improves folate levels across different communities and whether the benefits are shared fairly, particularly among groups at higher risk of deficiency.
The project, led by Dr Katie Dalrymple, Lecturer in Nutritional Sciences at King's, will collect and analyse 2,000 blood samples from women in early pregnancy, covering the period before, during and after the rollout of fortification. Samples will be drawn from established birth cohorts and antenatal clinics in London, Bradford, Edinburgh and Belfast to ensure broad ethnic, socioeconomic and geographic representation.
Folic acid fortification has the potential to prevent devastating birth defects, but it is essential that we understand how well this policy works in the UK's diverse population. This study will provide robust, UK-specific evidence on whether fortification improves maternal folate status equitably and whether it translates into better outcomes for mothers and babies.
Dr Katie Dalrymple, Lecturer in Nutritional Sciences at King's and project lead
Researchers will measure red blood cell and serum folate, vitamin B12 and homocysteine levels. These are all important markers of folate metabolism and will help identify whether folate is being used effectively in early pregnancy. They will also examine links between folic acid fortification, changes in biomarkers of folate status, and maternal and infant outcomes, including neural tube defects, fetal growth, preterm birth and infant neurodevelopment.
This is an important study for the health of the nation; folic acid fortification of flour has successfully reduced neural tube defects and some other congenital defects in many other countries, but few have measured folate status in different population groups. Now that this policy has been implemented in the UK, it is essential that we accurately follow its impact on folate status and health in our population.
Professor Lucilla Poston, Professor of Maternal & Fetal Health at King's and co-investigator on the grant
The findings from this study will provide critical evidence to inform future public health policy and ensure that fortification delivers meaningful health benefits for families across the UK.
