Dietary supplementation of calcium and vitamin D has been deemed one of the most important tools to fight against osteoporotic fractures increasing with aging of the population globally. Reports from early clinical trials demonstrated that supplementation of calcium and vitamin D for patients with osteoporosis can reduce the incidence of fragility fractures by decreasing bone loss and falls. However, following trials failed to demonstrate the efficacy of calcium and vitamin D for the prevention of osteoporotic fractures, questioning the need of calcium and vitamin D supplementation. Even metanalyses and system reviews presented opposite conclusions, depending on clinical trials included. Recent studies reported that excessive calcium supplement can increase cardiovascular risk such as non-fatal myocardial infarction and that excessive vitamin D supplement can produce more frequent falls than it is supposed to be. However, in spite of some arguments regarding the efficacy and safety of calcium and vitamin D supplementation, it seems to be essential to provide 800 to 1,000 mg elementary calcium and 800 to 1,000 IU vitamin D for the elderly whose intake of calcium and vitamin D is insufficient to prevent osteoporotic fracture.