Bioavailability of L-methylfolate

Bioavailability refers to the amount of a therapeutically active substance in circulation that is physiologically available to the body's cells.

L-methylfolate is the only natural, active folate immediately and completely bioavailable. Folic acid, on the other hand, is the synthetic form of folate and has no specific activity or benefit in the body. Folic acid must be converted to L-methylfolate before it can participate in homocysteine metabolism and DNA methylation.

Absortion and Transformation Steps

The following evidence demonstrates a higher bioavailability of L-methylfolate after orally administered 5mg dose of 5-MTHF compared with 5mg folic acid.1

7-Times more Bioavailable

Mean Pharmacokinetic Parameters

Folic acid has a prolonged biochemical pathway and must be reduced to dihydrofolate, then to tetrahydrofolate (THF). THF can follow three different biochemical processes, limiting the amount converted to L-methylfolate:

  1. THF can be transported into the portal circulation;
  2. THF can be stored in the tissue; or
  3. THF can be converted to L-methylfolate.

L-methylfolate requires no reduction steps once absorbed and is immediately bioavailable.