Is VKORC1 useful for Sport?

Based on the provided context, there is no evidence that VKORC1 is useful for sport. VKORC1 is primarily known for its role in vitamin K metabolism and warfarin sensitivity, not for athletic performance, recovery, or injury risk. Consumer DNA tests may claim links to bone health or vitamin K status, but these are not supported by strong evidence in the context of sports. The effect size of any genetic variant is likely small, and lifestyle factors dominate. Therefore, the evidence grade is 'marketing/unclear'. Athletes should not rely on VKORC1 testing for training or nutrition decisions. Safety note: VKORC1 variants affect anticoagulant response, but this is a clinical consideration, not a sports performance factor.