You are as old as your oldest part. For most people that part is their arterial system. Aging of the arteries produces stiffness followed by narrowing. And sadly, this is followed by Stroke, Heart Attack, Dissecting Aneurysm, Valve dysfunction and death. There are multiple lifestyle factors which contribute to this and should be corrected. But now, new evidence has emerged that Vitamin K is critical to keeping arteries flexible. Vitamin K activates special proteins in arteries and other soft tissues to keep calcium out, thereby helping to protect the artery from stiffness and plaque formation. At the same time, Vitamin K activates calcium binding proteins which add calcium to your bone improving skeletal strength. So K is a win, win by keeping Calcium where it needs to be. Recently, a long acting form of Vitamin K called MK-7 has been shown to reverse arterial stiffness. MK-7 is the preferred way to take you K vitamin, so it has been recently added to my top tier of supplements.