How are Folsäure and fertility related?

Folic acid (vitamin B9) is critical for cell division, DNA synthesis, and homocysteine regulation. Deficiency may impair fertility by contributing to ovulatory dysfunction, reduced egg quality, and elevated homocysteine levels. The MTHFR C677T variant is particularly relevant: TT carriers have reduced enzyme activity, leading to higher homocysteine – a risk factor for recurrent pregnancy loss and possibly reduced fertility. Evidence is moderate, based on observational studies rather than large RCTs. Supplementation with 400–800 µg/day is standard for women planning pregnancy to prevent neural tube defects, but its direct effect on conception is less certain. For MTHFR variant carriers, active folate (5-MTHF) may be considered, though strong clinical proof is lacking. Importantly, folic acid is not a fertility cure; a balanced diet rich in leafy greens, legumes, and fortified foods remains foundational. Genetic testing for MTHFR should not drive supplement decisions alone, as the effect is modest and lifestyle factors dominate.