Myths vs facts: Homocystein and Müdigkeit

Myths vs. facts: Homocysteine and fatigue. Homocysteine is a sulfur-containing amino acid derivative produced during metabolism. Elevated levels are considered a risk factor for cardiovascular disease and are often linked to deficiencies in B vitamins (B6, B12, folate). Some claim that high homocysteine directly causes fatigue. However, the evidence is weak: fatigue is a nonspecific symptom with many potential causes. A homocysteine test can indirectly indicate a vitamin deficiency, which may contribute to fatigue. But there are no robust studies proving a causal relationship between homocysteine and fatigue. Most data come from observational studies or mechanistic reasoning. A normal homocysteine level does not rule out fatigue, and lowering it with vitamins does not guarantee increased energy. For consumers: homocysteine tests are available, but interpretation requires clinical context. There is no direct evidence for homocysteine as a 'fatigue marker'.