Calcium is the primary mineral responsible for strong bones and Magnesium plays an essential role in proper bone mineralization. Zinc is involved in the synthesis of collagen in bone tissue while Vitamin D3 helps your body absorb Calcium from the diet. Because the body cannot produce these nutrients, adequate intake of Calcium, Magnesium, Zinc and Vitamin D3 can play a role in maintaining bone health. Over 100% Daily Value of Vitamin D3.