Major Joint Health Supplement Calcium / Vitamin D 500 mg - 200 IU Strength Tablet 150 per BottleDefy bone aging with Major calcium and a high level of vitamin D 3: Adequate calcium and vitamin D throughout life, as part of a well balanced diet, may reduce the risk of osteoporosis. One dose is two caplets; each dose contains: 200 IU vitamin D (as cholecalciferol) and 500 milligrams of oyster shell calcium. Compare to active ingredient in Os Cal a registered trademark of Aventisub LLC. A bottle contains 150 tablets.