Finecal-500 - Bone & Joint Health Supplement with Calcium Carbonate & Vitamin D3-150 Tablets About this item Contains up to a 75-day supply of Calcium 500 mg with Vitamin D3 250 I.U. Tablets, 150 tablets per box. Calcium is derived from an Organic source Oyester Shell. Vitamin D3 helps improve calcium absorption. Helps support strong bones.