Folate, also known as vitamin B9, is an essential micronutrient contained in green leaved vegetables, legumes and some nuts. It plays a fundamental role in the synthesis of genetic material, cellular division, neurological development and foetal development, during pregnancy. For these reasons, the WHO recommends that pregnant women or those planning a pregnancy— complement their diet with folic acid, the form of the vitamin contained in supplements and that significantly improves folate status as well as significantly reducing the risk of grave foetal malformations, among other pregnancy complications.
In the late 90s, given the evidence for systemic folate deficiency in the population, countries such as the USA and Canada introduced the mandatory fortification of staple foods such as flour or cereals, with folic acid. More than 60 countries around the world have since implemented similar mandatory legislation, but overall European countries have not. In the ongoing debate among experts in the field of Nutrition, the opinion that the diverse and balanced Mediterranean diet provides sufficient folate to meet the body’s requirements, persists. Recently, the British Government, which will introduce Mandatory fortification of flour with folic acid from 2026, has reopened the debate in Europe: a good diet guarantees sufficient folate to meet the body’s requirements? Is mandatory fortification necessary in the Mediterranean region?
To answer these questions, a research team from the Universitat Rovira i Virgili has studied Mediterranean Diet Adherence, dietary folate intake and blood folate status in the general population in Tarragona province. To do this, they analysed data regarding dietary habits in 740 people, collected between 1998 i 2002, and complemented this with a health check-up and analysis of the concentrations of folate and other vitamins in the blood. Michelle Murphy, researcher from the Department of Basic Medical Sciences of the URV, explained that the dietary habits at that time were more representative of the Mediterranean diet than those of today, and therefore relevant to consider in that context.
Low Mediterranean Diet Adherence
The results showed that contrary to popular belief, only a small part of the population studied —17.5%—, adhered well to a Mediterranean diet. Even in those that did, 15% did not meet the folate intake requirements established by the European Food Safety Authority and 8.5% had folate deficiency according to blood concentrations below WHO recommendations. In the case of participants with low Mediterranean Diet Adherence, the prevalence of dietary folate deficiency shot up to 71% and 25% in the case of blood deficiency in the vitamin. Apart from this, the study also reports deficiency in other important vitamins such as Vitamin B6, essential for nervous and immune system development and functions.
In short, in the majority of cases, good adherence to the rich and balanced Mediterranean diet is associated with adequate folate status. But the results also show that even good Mediterranean Diet adherence does not guarantee sufficient folate intake and/ or status. On the other hand, bad Mediterranean diet adherence is associated with a drastic drop in folate status – affecting 82.5% of the Mediterranean population studied. This leads to the most relevant conclusion to the study: the majority of the population is susceptible to deficiencies in folate and other essential vitamins.
Open the door to generalised fortification
From the laboratory, Murphy has already insisted on the importance of communication campaigns to raise awareness in the population regarding the necessity to supplement pregnant mothers, especially, with folic acid and vitamin B12. These results, go further and highlight possible systemic deficiencies in the Mediterranean population. Faced with this scenario, the research team highlights the need to, at least, open the debate regarding the mandatory fortification of staple foods, such as flour: “We’re talking about a public health measure that can prevent complications in foetal development with lifelong consequences, such as spina bifida. A priori, it seems coherent to take measures to prevent this”, they reason.
However, they also stress that to consider such a measure, more data on diet and vitamin uptake by the population, is required, and this means doing further research: “Without further data, we cannot unequivocally recommend, these measures. We suggest further research and to open the scientific and political debate regarding this topic”, Murphy points out. The team stresses that policies to improve the population’s diet, promoting the consumption of fresh and varied foods, are essential.
Image: Authors of the article, from left to right: Michelle Murphy, Ailende Eigbefoh-Addeh and Albert Salas-Huetos.
Reference: Ailende Eigbefoh-Addeh, Albert Salas-Huetos, Carla Ramos-Rodríguez, Santiago Ceruelo, Lídia Ríos, Per M. Ueland, Klaus Meyer, Joan D. Fernandez-Ballart, Michelle M. Murphy, Prevalent low Mediterranean diet adherence and low folate status in a Spanish Km 0 Mediterranean coast population, Current Research in Food Science, Volume 11, 2025, 101217, ISSN 2665-9271. https://doi.org/10.1016/j.crfs.2025.101217.
