welche vitamine bei müdigkeit — can a DNA test help?

A DNA test can provide clues about genetic variants affecting the metabolism of vitamins such as B12, folate, or vitamin D (e.g., MTHFR, VDR). However, fatigue is a multifactorial symptom with many causes – from sleep deprivation and iron deficiency to thyroid disorders. The effect sizes of most gene variants are small, and a DNA test cannot replace a blood test. At best, it may serve as a supplementary hint whether increased intake of certain vitamins could be beneficial. Without medical evaluation and laboratory diagnostics, supplementation is not recommended. The evidence is mostly observational (GWAS), not clinically confirmed. Bottom line: DNA tests do not reliably answer which vitamins help with fatigue – they are no substitute for a doctor's advice.