Vitamins K2 and D3
When supplementing with vitamin D, your body's ability to absorb calcium is greatly enhanced. Since many people already receive a good amount of calcium through diet - with some people supplementing calcium in addition - an optimal vitamin K intake is essential when supplementing with vitamin D.


Vitamin K-dependent proteins in the body act as potent inhibitors of vascular calcification. So adequate vitamin K will help to ensure calcium ends up in bone where it belongs, instead of calcifying various soft tissues. 27 28 29 30 31

Bone health benefits from both vitamin D and K as they work together, aiding in proper bone formation and maintaining bone density. 5 32 33 34 Both BMD and bone mineral content (BMC) have exhibited significant and sustained increase. 35 36
http://www.vitamindcouncil.org/about...ors/vitamin-k/