Lay opinion vs evidence: MTHFR Frauen

A common lay belief is that an MTHFR variant found in a direct-to-consumer DNA test requires switching from folic acid to methylfolate, especially for women planning pregnancy. However, current evidence does not support this. Major guidelines (e.g., USPSTF) recommend standard folic acid supplementation for all women of reproductive age, regardless of MTHFR genotype. Methylfolate has not been shown to outperform folic acid in preventing neural tube defects or improving pregnancy outcomes. Commercial DNA tests often overstate the clinical relevance of common MTHFR polymorphisms. The evidence is strong (human-strong) and based on a 2023 meta-analysis (PMID:37526720). Caveat: Rare, severe MTHFR deficiency is a different condition and is not detected by typical DTC tests. For the vast majority, standard folic acid is sufficient and safe. Personalized supplementation based on MTHFR status alone is not evidence-based and may lead to unnecessary expense.