Calcium Supplement With Vitamin D3 500mg Calcium + 2 00 IU Vitamin D3 Helps Reduce the Risk of Hip Fractures by 29%^ Easy to Swallow Proven Effective in More Clinicals Reasons to choose Os-Cal®: #1 Pharmacist recommended* Helps reduce the risk of osteoporosis Highly absorbable calcium Meets USP dissolution standards This Os-Cal Calcium+D3 has no sugar, lactose, carbohydrates or sodium. This Os-Cal Calcium+D3 has 500mg of elemental calcium; one Citracal + Vitamin D® has only 315 mg. This Os-Cal Calcium+D3 has 0 calories; one Viactiv has 20 calories. Osteoporosis. . .Adequate calcium and vitamin D as part of a healthful diet, along with physical activit.