The combination of Vitamin D2 and K2 is crucial in aiding the body in calcium absorption, keeping your bones strong and healthy and your arteries clear of blockages. While Vitamin D controls the absorption of calcium into the blood, Vitamin K2 controls where that calcium goes. Taking too much vitamin D2 without getting the right amount of vitamin K2 can lead to issues with excess calcium. If calcium isn't properly absorbed, it can cause calcium build-up/deposits in arteries and muscles.