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Gene & pathway reference · FROM DR. PURSER’S TEACHING

MTR

Makes the methionine synthase enzyme, which uses vitamin B12 in the conversion of homocysteine to methionine.

Based on teaching by Dan Purser, MD. How we prepare these guides

Updated Sep 23, 2026 · Educational reference

THE TEACHING CONNECTION

The B12-dependent step

The B12-dependent step

In Dr. Purser’s teaching map, MTR is the B12-dependent step that converts homocysteine back to methionine. This helps explain why a methylation discussion should include B12 as well as folate, and why adding more folate alone does not answer every question.

Putting the pieces together

MTRR helps keep the MTR enzyme working. Your B12 status and how you tolerate different B12 forms matter too. A common variant does not mean the enzyme is missing or that your homocysteine must stay high.

Where the VARS Triad and MTHFR Daily fit

If you are exploring homocysteine or cytokines, Dr. Purser may discuss MTHFR Daily and the VARS Triad: VARS Glutathione, VARS SOD, and VARS Catalase. He gives glutathione a central place in his approach to antioxidant support.

A gene result alone cannot tell you that you need these products or that they will treat a condition. Review your current results, medicines, goals, and tolerance with your clinician before choosing a product or dose.

A question to bring to your visit

Have B12 status, folate status and current homocysteine been considered together?

Reading your own results

Bring your original report, current results, health history, and medicines to your visit. This information can help you ask questions, but it cannot diagnose a condition or choose a supplement dose for you.

Variant lookup

These names can help you find an entry on your original genetic report. Seeing a name here does not tell you whether it affects your health or whether you need treatment.

Names you may see

Methionine Synthase