Vitamin B9 (Levomefolate Acid)

5-methyltetrahydrofolate (5-MTHF) is activated folate, and it differs to folic acid. The two forms of Vitamin B9, differ in their forms and how the body processes them, particularly in the context of MTHFR gene mutations. Folic acid is a synthetic form of Vitamin B9 that needs conversion to its active form, 5-MTHF in order to be utilised by the body for various metabolic processes.

In people with MTHFR gene mutations, the body's ability to convert folic acid into its active form is compromised, leading to reduced folate utilisation. In humans, the gut efficiently converts dietary folates (like leafy green vegetables) into 5-MTHF, but struggles with folic acid conversion. Folic acid often reaches the liver unmetabolised, while 5-MTHF bypasses the gastric barrier, and it is easily absorbed in the small intestine. This process ensures a higher folate uptake, making it particularly relevant for those with impaired folic acid conversion, such as those with MTHFR gene mutations. As a result, 5-MTHF may provide a more bioavailable form of Vitamin B9 which supports optimal fertility.

References:

Berti, C., Fekete, K., & Dullemeijer, C. (2010). Folate intake and markers of folate status in women of reproductive age, pregnant, and lactating women: A meta-analysis. The Journal of Nutrition, 140(11), 1981-1988. https://pubmed.ncbi.nlm.nih.gov/23024859/

Lamers, Y., & MacFarlane, A. J. (2012). Folate: Biochemistry and metabolism. In R. A. Harris (Ed.), Seal Nutrient Series: Folate (pp. 3-21). CRC Press/Taylor & Francis.

Scaglione, F., & Panzavolta, G.(2014). Folate, folic acid and 5-methyltetrahydrofolate are not the same thing.
Xenobiotica, 44(5), 480-488. https://doi.org/10.3109/00498254.2013.845705

Smith, A. D., Kim, Y. I., & Refsum, H. (2008). Is folic acid good for everyone? The American Journal of Clinical Nutrition, 87(3), 517-533. https://doi.org/10.1093/ajcn/87.3.517

Pietrzik, K., Bailey, L., & Shane, B. (2010). Folic acid and L-5-methyltetrahydrofolate: Comparison of clinical pharmacokinetics and pharmacodynamics. Clinical Pharmacokinetics, 49(8), 535-548. https://doi.org/10.2165/11532990-000000000-00000