D3 and K2 are fat-soluble vitamins and play a central role in calcium metabolism. Vitamin D3 promotes the production of proteins, which require the presence of vitamin K2 for carboxylation in order to function properly.
Vitamin D contributes to the maintenance of normal bones and teeth, the normal function of the immune system, the maintenance of normal calcium levels in the blood, the maintenance of normal muscle function, and the normal absorption/utilization of calcium & phosphorus by the body.