welche vitamine bei müdigkeit — what are common causes?

The question about which vitamins help with fatigue is valid, but causes are multifactorial and not always due to a single deficiency. The provided context focuses on ferritin and iron deficiency – a common cause of exhaustion. Low ferritin (<15–30 ng/mL) indicates depleted iron stores, leading to fatigue, poor concentration, and pallor. However, ferritin is an acute-phase reactant; inflammation can elevate it, masking true deficiency. Additional markers like soluble transferrin receptor (sTfR) and C-reactive protein (CRP) help differentiate. Vitamin B12 and vitamin D deficiencies are also frequent causes, though not covered in the given context. DNA variants (CHRNA5, MC4R, HFE) are not directly relevant to general fatigue. Allergy testing may help if allergic rhinitis contributes to tiredness, but it is not a first-line workup. Without specific lab results, the evidence is mixed. A medical workup including complete blood count, ferritin, vitamin B12, vitamin D, and thyroid function remains the gold standard.