Calcium carbonate is a mineral that is needed for many functions of the body, especially bone formation and maintenance.risedronate is in the group of medicines called bisphosphonates (bis fos fo nayts). it alters the cycle of bone formation and breakdown in the body. risedronate slows bone loss while increasing bone mass, which may prevent bone fractures.calcium carbonate and risedronate is a combination medicine used to treat or prevent postmenopausal and steroid-induced osteoporosis.