Evidence check: VKORC1 in the context of Sport

VKORC1 (vitamin K epoxide reductase complex subunit 1) is a key gene in the vitamin K cycle, regulating the activation of clotting factors and bone matrix proteins. In a sports context, it is discussed mainly regarding bone health and fracture risk – certain variants (e.g., rs9923231) can affect vitamin K-dependent carboxylation of osteocalcin, thereby modulating bone mineral density. The evidence is largely mechanistic, coming from association studies with moderate effect sizes. Direct performance relevance (e.g., endurance, strength) is not established. Moreover, VKORC1 is a classic pharmacogene – its variants determine warfarin dosing, which may be relevant for athletes on anticoagulation but not for healthy recreational sports. Inclusion in consumer DNA tests is often driven by pharmacogenetic interest, not sports medicine indication. Conclusion: The evidence for sports relevance is weak to moderate; any interpretation should clearly state the limitations of association data.