What to watch with VKORC1 and fatigue?

VKORC1 is a key gene in vitamin K recycling and coagulation factor synthesis. It is best known for its role in warfarin sensitivity: variants (e.g., rs9923231) can drastically lower required warfarin doses and increase bleeding risk. Fatigue is not a direct effect of VKORC1 variants, but it can arise indirectly – for example, from anticoagulant overdose (bleeding → anemia → fatigue) or from vitamin K deficiency impairing coagulation. Evidence linking VKORC1 directly to fatigue is weak; most data come from pharmacogenetic studies on warfarin. A DNA test alone cannot explain fatigue. Clinical blood markers (INR, ferritin, vitamin K status) are essential. Caveat: consumer tests often overstate clinical relevance. For unexplained fatigue, a physician should evaluate other causes (iron deficiency, thyroid, sleep disorders).