Can Folsäure help with Müdigkeit?

Folic acid (vitamin B9) is crucial for cell division and red blood cell production. Deficiency can cause megaloblastic anemia, whose main symptom is fatigue. In that case, supplementation can alleviate fatigue. However, evidence for a general anti-fatigue effect in individuals without proven deficiency is weak. Most studies show no benefit in healthy adults. Moreover, high folic acid intake (above 1 mg/day) can mask vitamin B12 deficiency, delaying detection of neurological damage. A blood test (serum folate, possibly homocysteine) is advisable before supplementing. The provided context contains no direct studies on folic acid and fatigue, so the answer relies on general physiological knowledge. Evidence grade: mechanistic (deficiency-anemia-fatigue), but not established for the general population. Caution against overdosing and interactions.