Understanding nutrition

Folic acid fortification: what is it?

As you may have seen in the news, folic acid will be added to UK flour to help prevent birth defects(1). So what is folic acid? Why is fortification necessary? and most importantly, how might this affect the UK population? 

Folic acid, a synthetic form of folate, is an important micronutrient in the human diet(2). Naturally found in leafy green vegetables and legumes, folic acid is a B vitamin essential for DNA synthesis and the production, maintenance and functioning of cells, in particular red blood cells(3). Folic acid is also critical during periods of rapid growth, including foetal development, where deficiency during pregnancy can cause Neural Tube Defects (NTDs) in babies(4). Up until now, within the UK, women have been advised to take 400 micrograms (µg) of folic acid a day for at least a month before conception and up to the 12th week of pregnancy. However, up to 50% pregnancies are unplanned, and women may forget, or are not aware that they should take the supplement(1).

Countries such as the US and Canada have adopted national programs to fortify food with folic acid such as cereal and flour, and have consequently been successful in reducing the prevalence of NTDs(2). In 1998, the United States and Canada made folic acid fortification of grain and cereal products mandatory. Women of childbearing age were advised to consume a minimum of 400µg folic acid per day, including fortified foods and foods naturally high in folic acid as part of a healthy diet(2). Consequently, within a few years the rate of NTDs fell by 25% – 50%. In the UK however, where fortification has not previously been mandatory, a large proportion of women including those young, less educated and vulnerable, have remained unaware of the need to take folic acid preconceptionally and as a result, there were no signs of decrease in NTDs(2). Thus, fortification had certainly proved to be a highly effective way to reach those at risk within society and thus protect population health(4).

Folic acid fortification has also been found to have secondary benefits to the population. Preliminary research suggests that folic acid may protect against particular cancers in children and reduce the risk congenital heart disease in new born babies(2). One 2006 study also found a substantial drop in the rate of stroke deaths between 1998 and 2002 in the United States and Canada, immediately following folic acid fortification, further emphasising the effectiveness of fortification and the potential benefits in addition to the prevalence of NTDs, including contribution towards the pathogenesis of several disorders in humans(2)(5).

Previously, there has been much debate around research suggesting that folic acid fortification could have worrying health consequences. A concern commonly raised was that increased folic acid concentrations may mask the signs of vitamin B-12 deficiency, leading to anaemia and neurological damage(6). Availability and sources of foods rich in folic acid raised further questions regarding the purpose of fortification programs, as folate is a water soluble B vitamin, naturally present in foods such as broccoli, chickpeas, liver, whole grain and citrus fruit; the majority of which are commonly available and regularly consumed in the human diet(5). This challenged the need for flour fortification programmes above other public health interventions such as national campaigns to raise the awareness of the importance of folic acid intake during early stages of pregnancy. 

However, scientists have now concluded that these concerns are not supported by sufficient evidence and therefore for the sake of pregnant women and new born babies, the fortification of flour in the UK will now be mandatory in order to prevent hundreds of birth defects as fortification programs in other countries have proven to do(1)(7). 

Written by: Meg Tooth

Instagram: meg.r.nutrition

Twitter: @meg_tooth


1. BBC News. Folic acid to be added to UK flour to help prevent birth defects. 20th September 2021. https://www.bbc.co.uk/news/health-58615838 

2. The ups and downs of folic acid fortification. (2008). Harvard Women’s Health Watch.15(7). 

3. Marshall, W., Lapsley, M., Day, A. (2016). Clinical Chemistry (8th ed.). Saint Loius: Elsevier Health Sciences UK.

4. Eichholzer, M., Tonz, O., Zimmermann, R. (2006). Folic acid: a public-health challenge. The Lancet (British Edition)367(9519), 1352–1361. DOI:10.1016/S0140-6736(06)68582-6

5. Preedy, V., Watson, R., Patel, V. (2011). Flour and breads and their fortification in health and disease prevention (1st ed.). Boston: Elsevier/Academic Press.

6. Smith, A., Kim, YN., Refsum, H. (2008). Is folic acid good for everyone? The American Journal of Clinical Nutrition87(3), 517–533. DOI:10.1093/ajcn/87.3.517.

7. Grosse, S., Berry, R., Tilford, M., Kucik, J., Waitzman, N. (2016). Retrospective Assessment of Cost Savings From Prevention: Folic Acid Fortification and Spina Bifida in the U.S. American Journal of Preventive Medicine50(5 Suppl 1), S74–S80. DOI:10.1016/j.amepre.2015.10.012.

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