According to recent findings, the benefits of vitamin D, in terms of bone strength and cardiovascular health, are greatly enhanced when combined with vitamin K. Vitamin D improves your bone health by helping you absorb calcium. However, it is vitamin K that directs calcium to your skeleton, to prevent it from being deposited in the wrong areas.
Vitamin K2 activates a protein hormone called osteocalcin, produced by osteoblasts, which is needed to bind calcium into the matrix of your bone. Osteocalcin also appears to help prevent calcium from depositing into your arteries.
Evidence shows that vitamin D is dependent on vitamin K, and that vitamin D toxicity is actually caused by vitamin K2 deficiency.