Phylloquinone (Vitamin K1) is found naturally in plants, especially green vegetables. Foods such as broccoli, cabbage, and asparagus are high in Vitamin K1, but since the vitamin is fat soluble, it is important to consume these with fat to increase bioavailability. Dietary sources of Vitamin K2 are very limited. The bacteria in your GI tract produce K2, but the body does not produce Vitamin K1. The body stores very little of either Vitamin K1 or K2.
Vitamin K1 plays an important role that Vitamin K2 can never compensate for. It is essential in the activation of Gla proteins, allowing calcium to be bound into the bone. Not only is this important to maintain strong bones, but without this critical binding of calcium, the calcium starts to harden the soft tissues, hardening the arteries and causing pain around the joints.* Thus, Vitamin K1 supports both healthy bone, and promotes occasional and minor pain relief in the joints.*