Keep 5-MTHF in Dietary Supplements

A new proposed legislation is calling for dietary supplement companies to no longer be able to list “folate” on their labels. This legislation would force supplement companies to offer only folic acid. Why is this harmful for the average consumer?

Folate is a general term referring to a family of compounds, including folic acid. Good sources of dietary folate include legumes and dark green leafy vegetables. These foods contain folate primarily in the activated form, (L)-5-methyl-THF (5-MTHF). This activated folate is the coenzyme that participates in numerous methylation reactions, including the synthesis and repair of DNA and cell membrane function. Proper methylation, utilizing 5-MTHF, plays a key role in cell division and growth, particularly important for pregnancy and infancy, as well as healthy red blood cell development, detoxification, immune function, cardiovascular health and mood.

Folic acid is just one member of the folate group. It is used in dietary supplements because it is so stable, but rarely occurs in nature. Unlike 5-MTHF, folic acid requires enzymatic reduction in order to function as a methyl donor. While synthetic folic acid can be converted to 5-MTHF in the body, this process requires the enzyme 5,10-methylene tetrahydrofolate reductase (MTHFR). Estimates indicate that up to 30-40% of the population can have genetic variations that impair MTHFR from effectively activating folic acid to 5-MTHF.

This means that up to a third of the population may not be getting enough folate, particularly if they are not eating legumes or dark green leafy vegetables regularly. Additionally, these individuals may have an excess of unmetabolized folic acid. Some research has suggested that large amounts of unmetabolized folic acid can increase risk of prostate, lung or colon cancer. For these individuals, supplemental folate must be in the form of 5-MTHF.

Please send a letter to the FDA today telling them that dietary supplement companies should be allowed to use 5-MTHF!

References

1. Bailey SW, Ayling JE. The extremely slow and variable activity of dihydrofolate reductase in human liver and its implications for high folic acid intake. Proc Natl Acad Sci U S A. 2009;106(36):15424-9.
2. Ebbing M, Bønaa KH, Nygård O, et al. Cancer incidence and mortality after treatment with folic acid and vitamin B12. JAMA. 2009 Nov 18;302(19):2119-26. 
3. Figueiredo JC, Grau MV, Haile RW, et al. Folic acid and risk of prostate cancer: results from a randomized clinical trial. J Natl Cancer Inst. 2009 Mar 18;101(6):432-5.
4. Kelly P, McPartlin J, Goggins M, et al. Unmetabolized folic acid in serum: Acute studies in subjects consuming fortified food and supplements. Am J Clin Nutr. 1997;65:1790-95.
5. Troen AM, Mitchell B, Sorensen B, et al. Unmetabolized folic acid in plasma is associated with reduced natural killer cell cytotoxicity among postmenopausal women. J Nutr. 2006;136(1):189-94.
6. Sharp L, Little J. Polymorphisms in genes involved in folate metabolism and colorectal neoplasia: a HuGE review. Am J Epidemiol. 2004; 159(5):423-43.