Vitamin K1 in the form of phytonadione is popular among people who have concerns about their blood not clotting properly. This may include people who are taking blood thinners or have a family history of bleeding disorders. That’s because vitamin K plays a key role in the normal coagulation of blood cells. Vitamin K is also important for the metabolism of calcium and the formation of strong bones and teeth. While vitamin K1 is a fat-soluble vitamin, it is not stored in the body like other fat-soluble vitamins. Therefore, taking a high potency daily supplement with vitamin K may help ensure that you have adequate levels of K1 when your body needs it. All Mason Natural products are produced in a GMP certified facility and tested for purity.