How common is folic acid deficiency in the UK?

December 20, 2025 •

4 min read

According to UK National Diet and Nutrition Survey data from 2008-2019, folate levels across the population were in decline, indicating that folic acid deficiency is a common and persistent health concern in the UK. Significant portions of the population, particularly young women, have inadequate folate levels, prompting the government to mandate fortification of non-wholemeal flour.

Quick Summary

This article examines the prevalence of folic acid deficiency in the UK, analyzing National Diet and Nutrition Survey data and highlighting key demographics at risk. It details the symptoms, causes, and health implications of low folate status and explains public health initiatives, such as mandatory flour fortification, designed to combat this issue.

Key Points

Prevalence: Folic acid deficiency has been common in the UK, with national surveys showing declining folate levels across the population, especially among women of childbearing age.
Mandatory Fortification: As a result of persistent low folate status, the UK government mandated the addition of folic acid to non-wholemeal wheat flour, aiming to boost population-wide intake.
At-Risk Groups: Key risk factors for deficiency include a poor diet, lower socioeconomic status, specific medical conditions like coeliac disease, certain medications, and excessive alcohol use.
Health Impact: A deficiency can lead to megaloblastic anaemia, with symptoms such as extreme tiredness, a sore tongue, and pins and needles.
Neural Tube Defects: Critically, low folate levels in women of reproductive age significantly increase the risk of birth defects like spina bifida.
Addressing the Deficiency: Treatment involves prescribed folic acid tablets, while prevention relies on dietary intake of folate-rich foods and, for pregnant women, supplementation.

The Prevalence of Folic Acid Deficiency in the UK

Recent data from the UK's National Diet and Nutrition Survey (NDNS) has painted a clear picture of folate status in the country, revealing that folic acid deficiency is a prevalent issue affecting large segments of the population. The NDNS, which covers data from 2008-2019, showed a concerning decline in both serum and red blood cell (RBC) folate concentrations across all age and sex groups. This declining trend ultimately led to the government's decision to mandate fortification of non-wholemeal flour with folic acid, a public health measure intended to increase population-wide intake.

Key Statistics on Folate Status

The statistics reveal significant proportions of the UK population have sub-optimal folate levels. For example, between 2008 and 2019, the proportion of women of reproductive age (16-49 years) with RBC folate concentrations below the threshold required to minimize the risk of neural tube defects (NTDs) rose from 69% to 89%. For younger women aged 21-25, one study found over a quarter (26.3%) had serum folate levels below the threshold for clinical deficiency (< 7 nmol/L). These figures demonstrate that despite long-standing advice on supplementation, dietary intake alone is often insufficient, especially among vulnerable groups.

Demographic Risk Factors

Certain demographics are disproportionately affected by low folate status. Women of childbearing age are a primary concern due to the link between folate deficiency and serious birth defects, such as spina bifida and anencephaly. Additionally, other risk factors play a significant role in determining who is most vulnerable:

Dietary Habits: People with a generally poor or unbalanced diet, including those who consume excessive alcohol, are at risk. Vegetarians and vegans need to be mindful of their intake, though many fortified foods are suitable.
Lower Socioeconomic Status: Studies have shown a correlation between lower household income and poorer folate status, suggesting that financial constraints can impact dietary quality and access to supplements.
Medical Conditions: Conditions that affect nutrient absorption, such as coeliac disease and Crohn's disease, significantly increase the risk of deficiency. Certain medications, including some for epilepsy, also interfere with folate absorption.
Age: While the NDNS showed declining levels across most age groups, older individuals, particularly those in institutions, can be more susceptible to deficiency.

Symptoms and Health Consequences

Symptoms of folic acid deficiency often develop gradually and can mimic those of vitamin B12 deficiency. A common symptom is fatigue due to megaloblastic anaemia, where the body produces abnormally large, immature red blood cells.

Common symptoms of folate deficiency:

Extreme tiredness and lethargy
Lack of energy
Sore and red tongue (glossitis)
Mouth ulcers
Pins and needles (paraesthesia)
Changes in mood, irritability, and depression
Diarrhea and other digestive issues

If left untreated, these deficiencies can lead to more serious neurological and heart-related complications, especially if there is an underlying vitamin B12 deficiency that is masked by folic acid treatment.

Treatment and Public Health Action

For diagnosed folic acid deficiency, treatment typically involves prescribed daily folic acid tablets for around four months, alongside dietary advice. Patients with malabsorption issues or chronic conditions may require longer-term treatment. Public health efforts are crucial for prevention, and the UK has long advised women who could become pregnant to take a daily 400 micrograms (mcg) folic acid supplement.

However, a lack of awareness and inconsistent adherence to supplementation guidelines have led to low uptake, particularly among younger women and those from lower-income backgrounds. This was a key driver behind the UK government's decision, announced in 2021, to introduce mandatory folic acid fortification of non-wholemeal wheat flour. Set to come into force by the end of 2026, this measure is expected to significantly increase baseline folate intake across the population, aiming to prevent around 200 cases of NTDs annually.

Comparison: Mandatory Fortification in the UK vs. Other Countries

For decades, the UK lagged behind many other nations in implementing mandatory flour fortification, a practice proven to be effective and cost-efficient. The table below highlights the difference in approach and outcomes.


Feature	United Kingdom (Pre-Mandatory Fortification)	United States & Canada
Fortification Status	Voluntary fortification only.	Mandatory fortification since 1998 (USA) and 1997 (Canada).
Population Folate Levels	Declining from 2008-2019, with large proportions of at-risk groups below recommended thresholds.	Higher and more stable population-wide folate status.
Impact on NTDs	NTD rates remained relatively high compared to countries with mandatory fortification.	Significant reductions in NTD prevalence post-fortification.
Key Public Health Approach	Relied primarily on individual supplementation, which had low uptake.	Population-wide approach via mandatory food fortification to ensure wider coverage.

Conclusion

The evidence clearly shows that folic acid deficiency has been a common and under-addressed problem in the UK. Data indicates a significant portion of the population, especially women of childbearing age, did not meet optimal folate levels through diet and voluntary supplements alone. The introduction of mandatory folic acid fortification in non-wholemeal flour marks a major, albeit long-delayed, public health step towards increasing baseline folate intake. While this policy is a critical move to reduce the incidence of neural tube defects, continued efforts to promote supplementation among high-risk groups, particularly pregnant women, remain essential for optimal health outcomes. The long-term impact of the new fortification policy will be a key area for future health monitoring in the UK.

[https://www.fertilityfamily.co.uk/blog/benefits-of-taking-folic-acid-when-trying-to-conceive/]

Frequently Asked Questions

National Diet and Nutrition Survey (NDNS) data has shown that a significant proportion of the UK population has low folate status. The NDNS (2008–2019) reported declining folate levels over this period, with substantial percentages of many age and sex groups falling below recommended thresholds for folate insufficiency.

Women of childbearing age are a particularly high-risk group, with studies showing a large majority have inadequate folate levels to prevent neural tube defects. Other at-risk groups include those with poor diets, lower household incomes, excessive alcohol consumers, and individuals with malabsorption conditions like coeliac disease.

Key symptoms often include extreme tiredness, lack of energy, pale skin, a sore and red tongue, mouth ulcers, irritability, and pins and needles. These symptoms can overlap with vitamin B12 deficiency, so a doctor's diagnosis is important.

In response to concerns about widespread low folate status, the UK government announced in 2021 the intention to mandate the fortification of non-wholemeal wheat flour with folic acid. This measure is a public health initiative designed to increase population-wide intake and reduce the incidence of neural tube defects.

Some concerns have been raised, primarily relating to the potential masking of a coexisting vitamin B12 deficiency, especially in older adults, since high doses of folic acid can correct anaemia symptoms while nerve damage progresses. However, many countries with mandatory fortification have not found an increase in this issue, and the UK government's policy balances these concerns.

The NHS strongly recommends that women take a daily 400 microgram folic acid supplement from before they conceive until the 12th week of pregnancy. This is essential to prevent neural tube defects in the baby, as it's difficult to get enough from diet alone.

Treatment usually involves a course of prescribed daily folic acid tablets, often for around four months, to restore normal folate levels. Dietary advice to improve intake of folate-rich foods is also provided.