Folic Acid in Flour: What's Changing and Why Does it Matter? (Part one)

From December 2026, new legislation will require folic acid to be added to non-wholemeal common wheat flour in the UK, bringing a significant change to the way much of our flour is produced.

The aim is to reduce the number of babies born with neural tube defects, including spina bifida, by increasing the amount of folic acid available to women who could become pregnant. It's a public health measure that's been under consideration for many years, but its implementation raises important questions about informed consent and the restriction of consumer choice.

The use of wheat flour as a vehicle for folic acid fortification has been adopted in more than 60 countries worldwide (including Australia, Canada and the USA), either mandatorily or voluntarily. Interestingly, the European Union (EU) doesn't have a mandate for universal or mandatory fortification of foods (such as flour) with folic acid.

As a nutritional therapist and a flour miller's wife, I believe it's worth understanding not only why this change is happening, but also what it means for our everyday food choices and our health.

How Did we Get Here?

In 2006, the Scientific Advisory Committee on Nutrition (SACN), which advises the UK government on nutrition and health, recommended mandatory fortification of flour with folic acid. The recommendation was intended to improve folate status among women most at risk of pregnancies affected by neural tube defects.

SACN reaffirmed its recommendation in 2009 and again in 2017, following further consideration of the evidence, including potential adverse health effects.

The issue subsequently moved towards legislation. Following a UK-wide consultation process, the governments of England, Scotland, Wales and Northern Ireland agreed to introduce mandatory folic acid fortification of non-wholemeal wheat flour.

In September 2021, the four governments announced their intention to proceed. A further consultation in 2022 considered changes to the existing Bread and Flour Regulations, including how the new requirement would be implemented and its impact on flour millers and other food businesses.

The resulting legislation, the Bread and Flour (Amendment) Regulations, was introduced in England in November 2024, with equivalent legislation across the other UK nations.

The new requirement is due to take effect on 13 December 2026.

What Exactly is Changing?

The existing Bread and Flour Regulations already require certain nutrients to be added to non-wholemeal common wheat flour, including calcium carbonate, iron, thiamin (vitamin B1) and niacin (vitamin B3).

From December 2026, folic acid will be added to this list. The required amount is 250 micrograms per 100 grams of flour. This is a mandatory addition, regardless of how much folate the flour naturally contains.

The requirement applies to non-wholemeal common wheat flour produced in or imported into the UK, subject to specified exemptions. Wholemeal flour and flours made from other grains, including rye and spelt, are outside this particular fortification requirement.

There is an exemption for flour produced by qualifying small mills, these are mills that produce under 500 metric tonnes of flour per year. The Real Bread Campaign and The Traditional Cornmillers Guild (there is a directory of mills on their website) fought this legislation, disappointingly The Soil Association and other organic certifiers who had an opportunity to challenge this didn't speak up. Flour produced to make matzos, communion waters, starch or gluten are also exempt.

This distinction matters because the change affects not just flour manufacturers, but also non-wholemeal wheat flour used in everyday foods, from pasta, bread and biscuits to cakes and pastries.

What is the Difference Between Folate and Folic Acid?

Folate is vitamin B9, an essential bioavailable nutrient involved in DNA synthesis, cell division and normal development. It occurs naturally in foods including leafy green vegetables, legumes (lentils, chickpeas, kidney beans, and black beans), liver (such as chicken liver), eggs, nuts and seeds, and other vegetables such as asparagus, broccoli, beets, brussel sprouts and cauliflower.

Folic acid is the synthetic form of folate and used in supplements and food fortification, and behaves entirely differently in the body.

Folic Acid and Individual Differences in Nutrient Metabolism

Genetic variations can influence the way the body processes folate. Synthetic folic acid requires processing by the enzyme DHFR before it can enter the body's folate cycle. Certain DHFR variants have been associated with differences in folic acid metabolism and may influence the levels of unmetabolised folic acid in the blood.

The MTHFR gene plays a different role, helping convert folate into 5-MTHF, the biologically active form of folate that circulates in the blood and provides methyl groups for the conversion of homocysteine to methionine. This makes it important for methylation and other essential cellular processes.

I think there's a lot of confusion around MTHFR, with much of the debate focusing on this gene without considering the wider folate cycle. While MTHFR is important for converting folate into 5-MTHF, DHFR has a different role and is particularly relevant when looking at how the body processes synthetic folic acid before it enters the folate cycle. Genetic variations affecting these enzymes may influence different stages of folate metabolism, so focusing on MTHFR alone gives an incomplete picture. Understanding the distinction is important when considering how individual genetic variations may affect nutrient metabolism.

These pathways are important for DNA synthesis and repair, the recycling of homocysteine and other essential cellular functions. Whilst there is public debate about the impact of genetic variations, the results always need to be considered alongside diet, lifestyle and nutritional status, rather than in isolation.

Having a genetic variant may mean you process certain forms of folate differently from other people. Rather than worrying about occasional exposure, the focus should be on building a nutrient-dense diet rich in naturally occurring folate and reducing reliance on heavily processed, fortified foods where possible. For most people, the additional folic acid obtained from fortified flour is unlikely to cause harm, although individual circumstances and overall intake are relevant, particularly when considering the combined contribution of fortified foods and supplements.

I would encourage you to look at the bigger picture of what you consume. Are you eating a lot of fortified foods, or does your diet generally centre on whole foods and naturally nutrient-rich ingredients? How can you start changing the balance?

If you have personal health concerns, nutrigenomics testing can provide useful insights into genetic variations relevant to nutrient metabolism.. When interpreted in the context of your diet, lifestyle and nutritional status, it can help inform a more individualised approach to nutrition.

I've put together a handout about epigenetics, exploring not just the science but also the food and lifestyle choices that influence our health. Nutrition is one of the most potent and well‑studied epigenetic regulators. Many nutrients act as raw materials or cofactors for epigenetic processes. If you'd like to find out more, you can download the handout here.

What Else Does the Research Tell Us About Folic Acid?

Research into higher folic acid intake has raised questions about several areas of health, including prostate cancer, cardiovascular health, vitamin B12 deficiency and the potential effects of unmetabolised folic acid (UMFA).

Prostate cancer

A 2012 systematic review and meta-analysis of six randomised controlled trials found a 24% relative increase in prostate cancer incidence among men taking folic acid supplements compared with control groups. The dose ranged from 800-2,500mcg. However, a separate meta-analysis published in 2013 found no statistically significant increase in prostate cancer risk.

Cardiovascular health

A 2004 study published in the New England Journal of Medicine investigated the effects of folic acid combined with vitamins B6 and B12 in patients who had undergone coronary stenting. Although the supplementation lowered homocysteine levels, the researchers observed a higher rate of restenosis, where the treated artery narrows again, in the vitamin group compared with the placebo group.

Vitamin B12 deficiency

One established concern with high folic acid intake is its ability to correct the anaemia associated with vitamin B12 deficiency without addressing the underlying deficiency or preventing neurological damage. This can potentially delay recognition of B12 deficiency, making it important to consider vitamin B12 status when assessing folate intake.

Unmetabolised folic acid (UMFA)

Folic acid must undergo enzymatic processing before it can be used in the body's folate pathways. When the body's capacity to process it is exceeded, unmetabolised folic acid (UMFA) can appear in the bloodstream.

Research has associated UMFA with reduced natural killer cell activity, while a study in older adults found an association with lower cognitive test scores in those with low vitamin B12 status. However, these findings do not establish cause and effect. A 2026 systematic review concluded that current evidence does not establish that UMFA independently causes harm in humans. Its long-term health implications remain uncertain, and further research is needed.

Unmetabolized Folic Acid in Plasma Is Associated with Reduced Natural Killer Cell Cytotoxicity among Postmenopausal Women (2006). Read the study

A Daily Dose of 5 mg Folic Acid for 90 Days Is Associated with Increased Serum Unmetabolized Folic Acid and Reduced Natural Killer Cell Cytotoxicity in Healthy Brazilian Adults (2017). Read the study

Circulating Unmetabolized Folic Acid and 5-Methyltetrahydrofolate in Relation to Anemia, Macrocytosis, and Cognitive Test Performance in American Seniors (2010). Read the study

Unmetabolized Folic Acid: Biology, Epidemiology, and Clinical Consequences: A Systematic Review (2026). Read the review

Conclusion: A Food-First Approach to Folate

The introduction of mandatory folic acid fortification raises important questions about how we approach nutrition and public health, as well as raising important questions about informed consent and the restriction of consumer choice.

The evidence discussed here doesn't establish that mandatory fortification will cause harm. However, it highlights the importance of considering the form of a nutrient, the amount consumed and the individual's wider nutritional status, rather than assuming that one approach will have identical implications for everyone.

My approach to nutrition has always been food first. Naturally occurring folate is found in foods such as leafy green vegetables, legumes (lentils, chickpeas, kidney beans, and black beans), liver (such as chicken liver), eggs, nuts and seeds, and other vegetables such as asparagus, broccoli, beets, brussel sprouts and cauliflower. Building a varied, nutrient-dense diet around these foods provides folate alongside the many other nutrients needed for health. It also encourages us to think about the overall quality of our diet, rather than focusing on a single nutrient in isolation.

It's equally important to consider the bigger picture: how much folic acid you obtain from fortified foods and supplements, whether you have any nutritional deficiencies, and whether individual factors warrant further investigation. Genetic variations can offer useful insights into nutrient metabolism, but they need to be interpreted in context rather than treated as a prediction of future health.

Ultimately, nutrition isn't about fear or avoiding every possible risk. It's about understanding what your body needs, making informed choices and building strong foundations for long-term health. A varied, nutrient-rich diet, an awareness of what is added to the foods we eat, and an understanding of individual needs offer a practical place to start.

How Can I Object to This Fortification

Write to your MP.

And sign Dr Clare Craig's petition calling on the Government to stop the fortification of flour with synthetic folic acid: https://petition.parliament.uk/petitions/769589 which closes on 8 December 2026.

If you’d like to explore how your diet, lifestyle and individual nutritional needs could be influencing your health, I offer a 60-minute Insight Session to help you make sense of your concerns and identify potential next steps.

If you're interested in how your genetics may influence the way you process nutrients, including folic acid, nutrigenomics DNA reports can offer further insight and help inform a more personalised approach to nutrition.

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