We need to optimize our Vitamin D levels and of course sun exposure is the best source, however it may be that many people are unable to acquire enough from the sun and therefore require supplements. Combining Vitamin D, K2 and Magnesium has a greater effect on Vitamin D levels, than either individually.
You need 245% more Vitamin D orally if you are not taking magnesium and vitamin K2 concurrently. What this means in practical terms is that if you take all three supplements in combination, you need far less oral vitamin D in order to achieve a healthy vitamin D level.