Lay opinion vs evidence: MTHFR Alltag

MTHFR is one of the most hyped genes in consumer nutrigenetics. Lay opinion often claims that having a variant (e.g., C677T) means you must avoid folic acid and take methylfolate instead. The evidence is more nuanced: the variant reduces enzyme activity by 30–70 %, which can slightly raise homocysteine. However, for the general population, the health impact is small. Randomized trials do not support routine methylfolate supplementation over folic acid in MTHFR carriers. Importantly, pregnant women with MTHFR variants should still take standard folic acid (400 µg) – it is safe and effective. Most direct-to-consumer marketing overstates clinical relevance. In everyday life, a balanced diet rich in leafy greens is sufficient. A DNA test can provide insight but should not replace medical advice. Caveat: Do not self-prescribe high-dose methylfolate without a clear indication.