L5methyltetrahydrofolate

L5methyltetrahydrofolate, often abbreviated as L-methylfolate or 5-MTHF, is the biologically active form of folate. Folate, also known as vitamin B9, is essential for numerous metabolic processes in the body. L5methyltetrahydrofolate is the predominant form of folate found in circulation and is the form that can cross the blood-brain barrier.

Its primary role is as a cofactor in the methylation cycle. This cycle is crucial for the synthesis of neurotransmitters like serotonin, dopamine, and norepinephrine, as well as for DNA synthesis and repair, and the metabolism of homocysteine. Elevated levels of homocysteine are associated with various health concerns, and L-methylfolate plays a key part in its conversion back to methionine, thereby helping to regulate homocysteine levels.

Many individuals have genetic variations, such as in the MTHFR gene, that can impair their ability to convert dietary folate into its active L-methylfolate form. In such cases, supplementation with L-methylfolate directly can be beneficial to ensure adequate folate status and support the body's critical methylation processes. It is available as a dietary supplement and is sometimes used in medical contexts to address folate deficiencies or support individuals with specific genetic predispositions.