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MTHFR Methylenetetrahydrofolate reductase

MTHFR (Methylenetetrahydrofolate reductase): 10 variants described, covering health risk, nutrition; nutrient interactions.

2 curated variants

Which MTHFR variants does Orviva describe?

rs1801131 Nutrition
MTHFR A1298C homozygous. Reduced enzyme activity; combined with C677T increases homocysteine risk.
rs1801133 Nutrition
MTHFR C677T homozygous. ~70% reduced enzyme activity. Higher folate/methylfolate needs. Elevated homocysteine risk.

8 further MTHFR variants in the knowledge base have only a brief annotation and are not listed here.

Which nutrients interact with MTHFR variants?

methylfolate strong evidence
MTHFR variants reduce enzyme activity (C677T heterozygous ~35%, homozygous ~70%), impairing folate-to-methylfolate conversion
Often considered alongside: methylcobalamin, pyridoxal-5-phosphate, riboflavin.
Lab markers that reflect this pathway: HCY, FOLATE, B12.

Dose ranges are deliberately not shown here; they depend on genotype, current levels and other medicines.

Genetic associations describe risk across populations, not a diagnosis for any one person. Most variants shift risk modestly and act alongside lifestyle, environment and other genes. Consumer DNA chips do not read every position and can be wrong at any single one. For general education only; talk to a clinician or genetic counsellor before acting on anything here, and never change a prescribed medicine without your prescriber.