Folic Acid in Your Flour: What You Need to Know (Especially if You Have IBD)

For many of us, baking from scratch has always felt like one of the simplest ways to know what's in our food. From December 2026, one ingredient will be there whether you choose it or not.

By December 2026, synthetic folic acid will be added to most non-wholemeal wheat flour in the UK. That means white bread, many supermarket loaves, plain flour, self-raising flour, pasta, crackers, commercially produced cakes and biscuits are all required by law to contain it.

Most people will never realise it's happened.

For those living with Crohn's disease, ulcerative colitis, or other gut conditions, it deserves a closer look. Not because folate is a problem - it isn't. Folate is essential. But synthetic folic acid is not the same thing as folate, and not everyone processes it in the same way.

Most People Will Soon Be Eating More Folic Acid Without Realising It - And For Some, That May Have Implications For Health

In Brief

• Most non-wholemeal wheat flour in the UK will contain added folic acid by December 2026

• Folate and folic acid are not the same thing

• People differ in their ability to process synthetic folic acid

• People with IBD may receive higher exposure due to greater reliance on wheat-based foods during flares

• Genetics, gut health and existing colorectal cancer risk may make this particularly relevant

Folate and Folic Acid Are Not the Same Thing

Folate is vitamin B9 as it occurs naturally in food - liver, eggs, lentils, leafy greens, broccoli, asparagus, avocado. Your body recognises it and uses it well.

Folic acid is a synthetic compound used in supplements and food fortification. It doesn't exist in meaningful amounts in whole foods. Before it can be of any use, it has to be converted through several enzymatic steps into an active form your cells can actually work with.

That conversion is the crux of the issue.

Why Some People Process Folic Acid Less Efficiently

The first enzyme responsible for processing synthetic folic acid is called dihydrofolate reductase (DHFR). In humans, this process is surprisingly slow - human DHFR activity averages less than 2% of that seen in rats, which is what much of the original safety levels were based on, and varies considerably from person to person. [1]

When we take in more than we can convert, the unconverted remainder - unmetabolised folic acid (UMFA) - accumulates in the bloodstream. UMFA has been linked with reduced activity of natural killer (NK) cells: the immune system's front-line defence against abnormal cell development. [2]

You may have come across MTHFR discussed online. It's relevant, but it sits downstream from DHFR - a secondary concern where synthetic folic acid is concerned. Around 40% of the population carries a variation in MTHFR that reduces its efficiency. [3] These aren't rare anomalies - they're part of normal human variation. Interestingly, some studies have reported a higher frequency of MTHFR variants in people with IBD. Those with these variants have an increased vulnerability to atopic conditions including eczema, asthma, and hay fever, and appear more affected by high synthetic folic acid exposure.

It's Easier Than You Might Think To Exceed Recommended Intakes

The daily recommendation is quoted as 400mcg - yet the original research suggested 100mcg was sufficient, rising to 200mcg for those following a vegan diet, with 400mcg described as "unnecessarily high exposure for many people." [4] How we arrived at the higher figure as standard is a question worth asking.

In practice, it's now easy to reach 1,200mcg or more in a single day: a bowl of fortified breakfast cereal, a sandwich made with fortified flour, and a standard multivitamin. Potentially six times what the research suggested was needed - and well beyond what the body can reliably convert.

During Flares, People With IBD May Receive The Highest Exposure - With Less Ability To Process It

During flares, the foods many with IBD lean on are often white bread, toast, crackers and plain pasta - precisely the foods most affected by the flour regulations and those that will carry the highest folic acid load.

At the same time, IBD itself can affect the body's ability to convert folic acid efficiently. Gut inflammation, altered absorption, and the impact of medication all play a role.

The result can be high intake of synthetic folic acid, impaired conversion, and a build up of UMFA - unconverted folic acid circulating in the bloodstream.

Folate Is Essential In IBD - But The Form Matters

It's not that we should avoid folate. Quite the opposite. Folate is essential for DNA repair, gut lining regeneration, red blood cell production and methylation - all processes that are under strain in IBD.

Some IBD medications directly affect folate metabolism. Methotrexate and Sulfasalazine, in particular. In these instances, your folate (B9) levels will be managed more closely by your IBD team and you will likely need to regularly supplement.

Dietary folate is harder to come by when your diet is restricted. The richest sources - liver, spinach, asparagus, lentils, broccoli - are often the foods least tolerated during a flare. If folate status needs supporting, the form of supplementation matters.

The form matters - Methylfolate (5-MTHF) is the pre-converted, active form the body actually uses - the same form that natural food folate becomes after processing. It bypasses the DHFR conversion steps entirely. It is the form found in better-quality supplements. Folic acid, the cheaper synthetic version, is what is being added to flour - and for people who already struggle to convert it well, that distinction is clinically significant.

Folic Acid, Colorectal Polyps and Cancer Risk: What the Research Shows

Natural folate from food appears broadly protective against colorectal cancer. The concern is not folate - it's whether synthetic folic acid behaves differently in people who already have pre-cancerous changes, and whether circulating UMFA suppressing NK cell activity contributes to risk in susceptible individuals.

The Aspirin/Folate Polyp Prevention Study - a large, randomised, placebo-controlled trial - assigned people with a history of colorectal polyps to either 1mg per day of folic acid or placebo. [6] One milligram. That's a dose now easily reached by someone eating fortified cereal, a fortified-flour sandwich, and taking a standard multivitamin. The trial found that extended supplementation was associated with an increased risk of sessile serrated adenoma/polyps - precancerous growths. The trial was stopped early on safety grounds - a finding that warrants consideration, particularly in those with existing colorectal cancer risk.

Now this is just one trial, but for people with IBD, who are already at higher risk of colorectal changes, it is worth consideration.

Atopic Conditions: Eczema, Asthma, and IBD

Other trials and large studies have shown impacts from folic acid supplementation too - increased risks of childhood asthma and eczema [7, 8] particularly where children were carrying MTHFR variants.

These findings don't prove causation, but they do suggest that folic acid exposure does not affect everyone equally - and that genetics matters in ways a population-level policy cannot account for.

IBD itself shares features with atopic conditions (like eczema, asthma, hayfever) in terms of immune dysregulation. For parents navigating a child's restricted diet alongside gut issues, this may feel uncomfortable. If options feel limited right now, I want to be clear: awareness matters more than perfection.

Which Flours Are Exempt From UK Folic Acid Fortification

Currently exempt from the UK regulations: pure wholemeal flour, flour from small mills (under 500 tonnes per year), and flour from non-common wheat species - spelt, einkorn, emmer, khorasan and durum are all currently excluded. [9]

Non-wheat flours - rye, oat, buckwheat, rice, almond - are outside the regulations entirely. However, some manufacturers may still add folic acid voluntarily.

Organic products are not exempt.

Gluten-free flour is technically excluded from the mandate, but some gluten-free products may still contain voluntarily added folic acid - checking labels is always worthwhile.

Folic acid must be declared on UK ingredient lists.

It's also worth knowing that mandatory fortification exists in Australia, Canada and the United States, so the same considerations apply. France and Italy have not adopted mandatory fortification.

How to Reduce Folic Acid Exposure if You Choose to:

• Source flour from small mills - farm shops, wholefood stores, and direct online orders are your best routes. The Real Bread Campaign website has guidance. [9]

• Use exempt grain flours for home baking - spelt, rye, oat or buckwheat - and check labels.

• Mill at home.

• Look for imported flours - and check ingredients.

• Check supplement labels: look for methylfolate or 5-MTHF rather than folic acid - this is the pre-converted form that bypasses the DHFR conversion steps entirely.

• Read ingredient labels on processed foods and breakfast cereals.

The Policy Is Population-Wide, But Responses Are Individual

Folate is an essential nutrient. Folic acid is a synthetic additive. The two are not biologically equivalent, and individuals do not respond to them in the same way.

My concern isn't that people are consuming folate. It's that a single approach is being applied to an entire population, including people whose biology, genetics and health conditions mean the assumption of uniform benefit doesn't necessarily hold.

For people living with IBD, who may rely more heavily on wheat-based foods during flares and who already face unique challenges around nutrient absorption, methylation and colorectal health, those questions deserve careful consideration.

At the very least, you deserve to understand what's in your food and why it matters.

Folate is routinely checked as part of IBD blood panels - if you're unsure of your last result, it's worth asking. If fatigue is a feature, ask for B12 alongside it - the two work together and both matter. And if you'd like to explore your genetic profile or discuss supplementation, get in touch.

References

1. Bailey SW, Ayling JE. The extremely slow and variable activity of dihydrofolate reductase in human liver and its implications for high folic acid intake. Proc Natl Acad Sci USA. 2009;106(36):15424–15429. PMC2730961

2. Playdon MC et al. Circulating unmetabolised folic acid and 5-methyltetrahydrofolate and risk of breast cancer; UMFA shown to reduce NK cell cytotoxicity. Cancer Epidemiol Biomarkers Prev. 2020. PMC7508257

3. Kuznetsov M et al. Adverse effects of excessive folic acid and implications for individuals with MTHFR C677T genotype. Nutrients. 2025. PMC11930790

4. Daly S et al. Minimum effective dose of folic acid for food fortification to prevent neural-tube defects. Lancet. 1997;350:1666–1669. PubMed 9400511

5. Dayan ZA et al. Weekly folic acid in paediatric IBD patients on methotrexate. Children (Basel). 2023. PMC10096625

6. Figueiredo JC et al. Folic acid supplementation and risk of colorectal neoplasia: Aspirin/Folate Polyp Prevention Study long-term follow-up. Am J Clin Nutr. 2019. PMC6766439

7. Mao Y et al. Maternal folic acid supplementation and risk of childhood asthma: meta-analysis of 18 studies, 252,770 participants. Front Pediatr. 2022;10:1000532. doi:10.3389/fped.2022.1000532

8. Bekkers MBM et al. Neonatal folate, MTHFR variants, and childhood eczema risk. Allergy. 2013. PubMed 23692062

9. Real Bread Campaign. How and where can I find folic acid-free flour and bread? 2025. https://www.sustainweb.org/realbread/articles/nov25-how-and-where-can-i-find-folic-acid-free-flour-and-bread/

Annette Hawes is a Registered Naturopathic Nutritional Therapist specialising in gut health and IBD. This article is for information and education only. Please speak with your IBD team or healthcare provider before making changes to your medication, supplementation, or diet.