My favorite natural medicines website is the Natural Medicines Comprehensive Database. The NMCD has new information about L-methylfolate which is being heavily promoted, especially on the Internet, by some manufacturers as a more active form of folic acid. Are they telling the truth? Here’s the information from NMCD:
L-methylfolate is in many prenatal vitamins such as Optinate, Neevo DHA, Prenate Elite; and regular vitamin supplements including Optimized Folate, MegaFolinic, and others. It’s also being used in medical foods for memory loss or depression, in products such as CerefolinNAC and Deplin.
According to the NMCD, “folates” are a mixture of different forms of the vitamin that occur naturally in food. Most supplements contain folic acid, a synthetic form of the vitamin. In the body, all of these forms are converted to L-methylfolate before entering the bloodstream and being stored by the body.”
The Database reports, “It is true that L-methylfolate is slightly better absorbed than folic acid. You’ll hear claims that L-methylfolate is a better alternative than folic acid because many patients have reduced activity of an enzyme that metabolizes folic acid to L-methylfolate. “
However, “so far there’s no proof that this makes a clinical difference.”
For example, studies show that equivalent doses of folic acid and L-methylfolate raise folate levels in pregnant women equally well.
Also, there is also no proof that L-methylfolate is any better than folic acid for preventing neural tube defects.
The NMCD tells us physicians, “Explain to patients that L-methylfolate is just as safe as folic acid for supplementation, but there is no reliable evidence that it’s more efficacious.”
Also, keep in mind that doses in some products are very high. Deplin contains 7500 mcg and CerefolinNAC contains 5600 mcg. These amounts are much higher than the 1000 mcg/day that has been linked to a higher cancer risk in some patients.
The NMCD webstite cautions, “Clinical research shows that taking folic acid daily in doses of 800-1200 mcg for 3-10 years significantly increases the risk of developing cancer and adverse cardiovascular effects compared to placebo.” This has been reported in studies in 2004 and 2006 studies in the New England Journal of Medicine, a 2009 study in the Journal of the National Cancer Institute, and a 2009 study in the Journal of the American Medical Association.
Also, according to the NMCD, researchers have recommended that “Doses above 1000 mcg per day should be avoided if possible to prevent precipitation or exacerbation of neuropathy related to vitamin B12 deficiency. However, there is some evidence that doses of 5 mg per day orally for up to 4 months can be used safely if vitamin B12 levels are routinely measured.
So, the bottom line, from my perspective, is that it’s likely safer and as or more effective to just use old time folic acid.