Best Naturals Calcium Magnesium Zinc with Vitamin D3, 300 Tablets - Calcium 1000 mg, Magnesium 400 mg, Zinc 25 mg & D3 600 IU per Serving (3 Tablets). Calcium, Magnesium & Zinc are essential minerals that work synergistically with one another to promote enhanced absorption. Calcium is necessary for strong bones and teeth, and Magnesium is important for healthy enzymatic activity. zinc is involved in the synthesis of collagen in bone tissue