It is recommended that anyone supplementing with vitamin D should also take vitamin K2. The important vitamin K2 is responsible for depositing calcium at the right places in the body – such as the bones and teeth. It also prevents calcification, the accumulation of calcium in places where it is not required – i.e. in the arteries and other soft tissues of the body. Because good dietary sources are limited for both vitamin D3 and K2, deficiencies associated with both are well documented.