An abundance of human clinical data reveals that vitamin K plays a critical role in maintaining healthy bone density by facilitating the transport of calcium from the bloodstream into the bone.1-5 Vitamin K is also required by calcium-regulating proteins in the arteries. Matrix Gla-protein (MGP) is a vitamin K-dependent protein, and it must be carboxylated to function properly. Poor vitamin K status leads to inactive uncarboxylated MGP (ucMGP), which accumulates at sites of arterial calcification.6,7 Since MGP is a potent local inhibitor of arterial calcification, MGP is important in relation to the health of the entire cardiovascular system. Without adequate vitamin K, calcium in the blood can bind to the arterial wall resulting in calcification.8,9 As people age, even a subclinical vitamin K deficiency can pose risks to the vascular system. Poor vitamin K status also results in increased circulating levels of undercarboxylated osteocalcin that is shown to be associated with increased bone loss in postmenopausal women.