How are Folsäure and allergy related?

The relationship between folic acid and allergies is not clearly established. Some observational studies suggest that high maternal folic acid intake during pregnancy may slightly increase the risk of childhood allergic diseases like asthma or eczema, possibly via epigenetic changes (DNA methylation). However, other studies found no association or even a protective effect. Importantly, the evidence is mostly epidemiological, not from randomized controlled trials. Also, natural food folate and synthetic folic acid differ in bioavailability and effects. For healthy adults without known allergies, there is no reason to avoid or specifically supplement folic acid. For those with allergies or planning pregnancy, standard recommendations (e.g., 400 µg/day before and during early pregnancy) should be followed without excessive high-dose supplements. Individual genetics (e.g., MTHFR variants) can affect folate metabolism, but a direct link to allergies is unproven. In summary, the evidence is conflicting and does not support clear clinical recommendations.