welche vitamine helfen bei müdigkeit — when to see a doctor?

Fatigue has many causes: sleep deprivation, stress, or nutrient deficiencies. Vitamins such as B12, B-complex, vitamin D, and iron (not a vitamin but crucial) can help if a deficiency is confirmed. However, self-supplementation without testing is often ineffective or risky (e.g., fat-soluble vitamin overdose). See a doctor if fatigue persists >2 weeks, is accompanied by unexplained weight loss, fever, shortness of breath, or severe exhaustion. Also seek medical advice if you have pallor, palpitations, or concentration issues – these may signal anemia, thyroid problems, or chronic illness. MyBody-X DNA tests can indicate genetic variants affecting vitamin metabolism (e.g., VDR for vitamin D), but they are not diagnostic. Evidence: practice-based; individual responses vary.