What role does VKORC1 play in fertility?

VKORC1 encodes a key enzyme in the vitamin K cycle, essential for blood coagulation. A direct role in human fertility is not established. Some indirect mechanistic hypotheses exist—vitamin K-dependent proteins may influence placental function or endometrial receptivity—but no robust clinical or GWAS evidence links VKORC1 variants to fertility outcomes. The evidence level is mechanistic/unclear. Consumers should be cautious about any direct-to-consumer test claiming a fertility link; such claims are not clinically actionable.