Evidence check: Folsäure in the context of Fruchtbarkeit

Folic acid (vitamin B9) is crucial for DNA synthesis and cell division – both key processes in fertility, especially for oocyte maturation and early embryonic development. However, the provided context contains no specific studies or genetic markers directly linking folic acid to fertility outcomes. In the scientific literature, folic acid supplementation before and during pregnancy is strongly recommended to prevent neural tube defects, but evidence for improved fertility (e.g., higher conception rates) is mixed. Some observational studies suggest a benefit, while randomized controlled trials often show no significant effect. Genetic variants in the MTHFR gene can affect folate metabolism, but they are not mentioned in the given context. Therefore, the evidence is rated as 'mixed'. A blood test for serum folate or homocysteine is more informative than a genetic test. Despite the mixed evidence for fertility itself, folic acid supplementation (400–800 µg/day) is widely recommended for women planning pregnancy, primarily based on its proven role in preventing birth defects.