What role does Folsäure play in Allergie?

Folic acid (vitamin B9) is involved in methylation and immune regulation, which may influence allergic responses. Some observational studies suggest that adequate folate status is associated with lower IgE levels and reduced allergy risk, but the evidence is inconsistent. In individuals with MTHFR variants (C677T, A1298C), conversion of folic acid to its active form (5-MTHF) is impaired, potentially affecting homocysteine levels and immune function. However, supplementation trials have not shown clear benefits for allergy prevention or treatment. High doses of synthetic folic acid may even be harmful, as unmetabolized folic acid can accumulate. For allergy management, a diet rich in natural folate from leafy greens and legumes is preferable. A blood test for homocysteine and B12 may be more informative than genetic testing alone. Caveat: Evidence is mainly observational/mechanistic; clinical decisions should be made with a healthcare provider.