Folate Update: Forms, Sources, and the MTHFR Mutation
Why Folate is Important
Folate is an essential B vitamin that is of particular importance during pregnancy and childhood.
One of the eight essential B vitamins, folate is especially notable for its role in growth and development. Because folate is key to the formation of genetic material, any time there are rapidly developing cells, folate will be involved in the process. Folate is necessary for the formation of red and white blood cells and is needed for cell division. Thus, it is especially important during infancy, childhood, adolescence, pregnancy, and any state that requires repair, building and healing. Severe folate deficiency can result in a condition known as megaloblastic anemia.
Folate is also related to heart health and when blood levels are low, the body’s homocysteine levels rise, which increases inflammation in the body and raises the risk of heart disease.
Pregnancy and Folate
Folate is especially critical in the first few weeks of pregnancy because it reduces the risk of neural tube defects (NTD), which are birth defects of the brain and spine. The two most common NTDs include anencephaly and spina bifida. It is advised that all women of childbearing age eat foods rich in folate and also consider taking a multivitamin which contains folic acid (the synthetic form of folate) or L-methylfolate. Since the United States began fortifying cereal grains with folic acid in 1998, the incidence of NTDs has decreased by 35%!
Many Americans do not consume the recommended amount of folate each day. The requirements are defined by Dietary Folate Equivalents, which converts naturally occurring folate as well as synthetic folic acid into standard units. The table below outlines the requirements for different groups.
|Table 1: Recommended Dietary Allowances (RDAs) for Folate |
|Birth to 6 months*||65 mcg DFE||65 mcg DFE|
|7–12 months*||80 mcg DFE||80 mcg DFE|
|1–3 years||150 mcg DFE||150 mcg DFE|
|4–8 years||200 mcg DFE||200 mcg DFE|
|9–13 years||300 mcg DFE||300 mcg DFE|
|14–18 years||400 mcg DFE||400 mcg DFE||600 mcg DFE||500 mcg DFE|
|19+ years||400 mcg DFE||400 mcg DFE||600 mcg DFE||500 mcg DFE|
DFE = Dietary Folate Equivalents
Source: National Institutes of Health, Office of Dietary Supplements, https://ods.od.nih.gov/factsheets/Folate-HealthProfessional/
Food Sources of Folate
Folate is naturally present in a number of nutrient-dense foods, including liver, lentils and dried beans, nuts, seeds, vegetables such as asparagus, dark leafy greens, Brussels sprouts, broccoli, beets, and fruits such as papaya, avocado, citrus and strawberries. The synthetic form of folate is folic acid. Folic acid is added to many multivitamins and prenatal vitamins and is also added to many fortified foods such as cereals, breads, rice and pasta.
Genetic Variations and the MTHFR Mutations
According to the Linus Pauling Institute at Oregon State University, “Folate status is influenced by the presence of genetic variations in folate metabolism, particularly those found in the 5,10-methylenetetrahydrofolate reductase (MTHFR) gene.”
Those with MTHFR gene mutations are less efficient at converting folic acid and folate into L-methylfolate, which is the active form of folate in the body.
Routine screening for the MTHFR mutation is not recommended at this time. While there are genetic variations in the capacity to convert folate and folic acid to the body’s active form, it is already known that incorporating naturally rich food sources of folate is a safe way to increase folate stores in the body. According to the National Institutes of Health, “Dietary supplements containing L-methylfolate might be better than folic acid for individuals who have the MTHFR gene mutation because their bodies can use this form more easily.”
Those who have had their DNA analyzed through a commercial service will be able to see whether they carry these mutations, though it takes some digging into the raw data. I recently had my DNA analyzed through 23andMe. While doing research for this blog, I took a close look at my raw data and found that of the two sites considered key to MTHFR and folate status, I have the normal or so-called “wildtype” on one site and on the other site, I am heterozygous, which means there is some reduction in my ability to convert folic acid to the body’s active form (L-methylfolate). I am not concerned though because folate rich foods such as dark leafy greens, asparagus, avocado, legumes and citrus are part of my daily diet.
Folate: Fact Sheet for Health Professionals, National Institutes of Health, Office of Dietary Supplements, https://ods.od.nih.gov/factsheets/Folate-HealthProfessional/
Folate: Fact Sheet for Consumers: https://ods.od.nih.gov/factsheets/Folate-Consumer/
Linus Pauling Institute: Micronutrient Information Center, Vitamins: Folate https://lpi.oregonstate.edu/mic/vitamins/folate
CDC. Updated Estimates of Neural Tube Defects Prevented by Mandatory Folic Acid Fortification — United States, 1995–2011. MMWR Morb Mort Wkly Rep. 2015: 64(01); 1-5.