How are VKORC1 and fertility related?

The provided context does not contain any direct information linking VKORC1 to fertility. VKORC1 encodes a key enzyme in the vitamin K cycle and is primarily studied for its role in warfarin sensitivity. While vitamin K-dependent proteins have been implicated in reproductive processes (e.g., placental function, sperm maturation), evidence for common VKORC1 variants affecting fertility is weak and not supported by the given knowledge base. Without clinical or GWAS data, any claimed relationship is speculative. Consumers should not use VKORC1 genetic results to guide fertility decisions. Evidence: unclear.