Why We Upgraded Folic Acid To Folate (5-MTHF) - Micronutrients.com

We recently upgraded our Core Micronutrients formula by changing our Folic Acid to 5-Methyltetrahydrofolate. We asked Dr. Ruth Leyse-Wallace to summarize why this switch was key, and why absorbing Vitamin B9 is so important.  

Forms of Vitamin B-9

  • Folate – in natural foods
  • Folic acid – synthetic, in some supplements – needs to be converted into Folate
  • Folacin – generic term for above terms
  • Folinic acid – a derivative, full activity
  • L 5 tetra methylhydrofolate or 5 formyl tetrahydrofolate – natural form found in supplements

What does Folate/vitamin B-9  do in the body?

Folate is the source of methyl groups (a carbon molecule with three hydrogen molecules attached) needed for many metabolic reactions. The addition or removal of methyl groups can activate or inactivate proteins, enzymes, hormones, or genes. For example, inadequate folate changes several steps of metabolism, causing  increased blood levels of homocysteine, which indicates a risk of cardiovascular disease. Low folate has been associated with changes in cognition such as memory, attention, and language. You can’t tell it, but folate is helping repair frequent, small damages to your DNA.*

Why Folate instead of Folic Acid? 

Folate is the active form of Vitamin B-9; it is the form that the body can use. Other forms (such as folic acid) must be converted by the body into folate to be active. Folate is absorbed 85% as efficiently as folic acid. This may be related to genetic alterations found in 20-55% of the population. One alteration is that of the enzyme 5, 10-methylenetetrahydrofolate reductase (MTHFR), known as the MTHFR c.677C>T polymorphism.

Is supplementation safe? 

The DRI for adults is 400 mcg/day. The Tolerable Upper Intake of folic acid for healthy adults is 1000 mcg/day. It is commonly believed that water-soluble vitamins pose no health risks if taken in large doses. However, folate does interact with a number of common and specialty drugs, so doses over 1000 mcg/day should be discussed with the prescribing physician.*

Supplementation of grain foods in the United States was approved in 1994 to counteract inadequate folate intake in young women and the resulting birth defects: neural tube defects and fetal alcohol syndrome. The incidence of neural tube defects has decreased since supplementation began.*


Smith, AD, Kim YI, Refsum H. Is folic acid good for everyone? Am J Clin Nutr. 2008 Mar;87(3):517-33.
Office of Dietary Supplements. Http://ods.od.nih.gov/factsheets/Folate-HealthProfessional/
http://lpi.oregonstate.edu/mic/vitamins/folate Reviewed in December 2014

*The statements on this site have not been evaluated by the Food and Drug Administration (FDA). These products are not intended to diagnose, treat, cure or prevent any disease.

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