Also Known As: L-methylfolate, Levomefolic acid, L-5-MTHF, L-5-methyltetrahydrofolate, (6S)-5-methyltetrahydrofolate, (6S)-5-MTHF, Metafolin, Deplin, Enlyte, Enlyte D, Levomefolate calcium, Levomefolate magnesium
Levomefolic acid (INN) (also known as L-5-MTHF, L-methylfolate and L-5-methyltetrahydrofolate and (6S)-5-methyltetrahydrofolate, and (6S)-5-MTHF) is the primary biologically active form of folate used at the cellular level for DNA reproduction, the cysteine cycle and the regulation of homocysteine. It is also the form found in circulation and transported across membranes into tissues and across the blood-brain barrier. In the cell, L-methylfolate is used in the methylation of homocysteine to form methionine and tetrahydrofolate (THF). THF is the immediate acceptor of one carbon units for the synthesis of thymidine-DNA, purines (RNA and DNA) and methionine. The un-methylated form, folic acid (vitamin B9), is a synthetic form of folate, and must undergo enzymatic reduction by methylenetetrahydrofolate reductase (MTHFR) to become biologically active.
It is synthesized in the absorptive cells of the small intestine from polyglutamylated dietary folate. It is a methylated derivative of tetrahydrofolate. Levomefolic acid is generated by MTHFR from 5,10-methylenetetrahydrofolate (MTHF) and used to recycle homocysteine back to methionine by methionine synthase (MS).
L-methylfolate is water-soluble and primarily excreted via the kidneys. In a study of 21 subjects with coronary artery disease, peak plasma levels were reached in one to three hours following oral or parenteral administration. Peak concentrations were found to be more than seven times higher than folic acid (129 ng/ml vs. 14.1 ng/ml).
Levomefolate calcium, a calcium salt of levomefolic acid, developed and produced by Merck KGaA, is sold under the brand names Metafolin (a registered trademark of Merck KGaA) and incorporated in Deplin (trademark of Pamlab, LLC).
Levomefolate magnesium is a magnesium salt of levomefolic acid, sold under the brand name Enlyte or Enlyte D by Jaymac Pharmaceuticals LLC.