Together, the two substances can slow bone loss that occurs with age. If you have relatively healthy bones, these nutrients can help prevent osteoporosis by maintaining an optimal level of bone density. If you already have osteoporosis, calcium and vitamin D will help to strengthen weak, brittle bones. In fact, even a small increase in bone density will reduce your risk of fracture. If you don't eat a balanced diet or if you avoid dairy products, you may want to take nutritional supplements.
Most multivitamins contain the recommended dosages of both nutrients.
Many antacids also have calcium as a primary ingredient and, when taken with vitamin D in the proper amounts, can help protect against bone loss.