Are you utilizing your folic acid? The case for metabolically active form of folic acid – L-5-MTHF

Roughly one-third of the general population may have a genetic variation that impairs their ability to properly utilize folic acid.

L-5-methyltetrahydrofolate (L-5-MTHF) is the metabolically active form of folic acid. The folic acid found in food has to be cleaved (digested) from protein carriers in order to be absorbed. This process is inefficient in some individuals. Once absorbed, dietary (and supplemental) folic acid has to then undergo several biochemical conversions in the body to become L-5-MTHF. Roughly one in three Americans have genetically inefficient enzymes that help create L-5-MTHF. By supplementing with L-5-MTHF, one can be assured of getting the benefits of folic acid, regardless of their ability to absorb or convert it to the active form. If you are an individual with impaired ability to utilize regular folic acid, L-5-MTHF supplementation can make a truly dramatic difference in your health.

L-5-MTHF plays a role in DNA synthesis and repair. Inadequate levels of 5-MTHF is linked to childhood leukemia. Cancers of the colon and breast are also associated with suboptimal L-5-MTHF status, as is the precancerous condition called cervical dysplasia. In a study involving smokers, high doses of folic acid and vitamin B12 reversed precancerous cellular changes in the lungs.

Folic acid’s importance to human health has to do in part with its role in a biochemical process called methylation. Methylation refers to the transfer of methyl groups (one carbon bound to three hydrogen atoms). Methylation occurs billions of times in the body each day and is essential for health.

L-5-MTHF is very important to genetic expression. Methyl groups are strategically placed on certain genes to inactivate them. Every cell in the human body has the genetic information to produce every other type of cell. The thing is that most of the genes are not active. Methyl groups (supplied indirectly by L-5-MTHF) silence the genes that should not be active in a given cell at a given time. This is obviously critical for good health. Some of the genes within our cells are tumor promoters. Proper methylation, which requires L-5-MTHF, keeps these genes silenced. The importance of L-5-MTHF involves more than its role in promoting proper genetic expression, DNA synthesis and repair.

L-5-MTHF also plays a role in dopamine and serotonin metabolism.

L-5-MTHF also plays an important role L-5-MTHF also plays an important role in detoxication of a variety of compounds, including environmental toxins (such as mercury, lead, arsenic and tin), medications, and some of the body’s own hormones. Estrogens are detoxified through methylation. Inadequate levels of L-5-MTHF cause potentially toxic build-up of estrogens in the body, which increases risk to breast, prostate and other cancers. Other conditions of estrogen excess, such as uterine fibroids and endometriosis, are also more likely to occur and be more severe. Histamine, epinephrine (adrenaline), and norepinephrine are also detoxified by methylation. Inadequate L-5-MTHF could therefore potentially worsen allergy and stress-related symptoms.

L-5-MTHF is critical for the detoxication of homocysteine. Conditions associated with elevated homocysteine levels include coronary artery disease, heart attack, stroke, deep vein thrombosis, peripheral vascular disease, miscarriage, birth defects, depression, sensorineural hearing loss, osteoporosis, cancer, arthritis, dementia, Alzheimer’s disease, Parkinson’s disease, and complications of diabetes. Do you know what your homocysteine level is?

© 2009-Dr. Vittoria Repetto

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10 responses to “Are you utilizing your folic acid? The case for metabolically active form of folic acid – L-5-MTHF

  1. Hi, So if you do have low levels, is there something you can do about it? If I have elevated homocysteine, what can I do? Would be glad to hear from you.


    • There is a vitamin company that has L-5-MTHF called Metagenics. I’d advise a B complex formula as B6 and B12 also help w/ homocysteine levels; their formula is called Glycogenics. There is an online store store at my website; you need to register and get a user name and password, plug it in and the red online store link will appear on the left


  2. Pingback: Nutrition Tips: Folic Acid: Killer or Cure-All? « Dr. Vittoria Repetto's Blog

  3. Great job, Der. Vittoria!

    You made it easier for people to understand the multiple roles of folic acid in the body. Nutrition is all biochemistry and tuff to understand. I think that’s why people don’t read about it in depth-including health care professionals.


  4. My ND just perscribed this for my son who is having increased behavior issues and eats a very limited diet, shows signs of major anxiety. I have seen that these can also be part of this but not much was mentioned here. I am wondering how soon someone might see improvements if this was the issue?


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