China’s elderly population is the first in the world, according to the literature, there are about 90 million osteoporosis patients, accounting for 7.1% of the total population, especially the incidence of postmenopausal women is higher, due to osteoporosis, 1/3 of women over 65 years of age have fractures, and the resulting death rate has exceeded the sum of malignant tumors such as breast cancer and cervical cancer. Osteoporosis is a common disease and a serious threat to the health of the elderly. With the increasing life expectancy of the population and the advent of an aging society, the incidence of osteoporosis has increased significantly, and the prevention and treatment of osteoporosis has become more and more important. Nowadays, many middle-aged and elderly people are influenced by advertisements and take some calcium tablets on their own, thinking that they can prevent or even treat osteoporosis. In fact, various methods of calcium supplementation, including taking various calcium products, are only basic measures to prevent and treat osteoporosis. First of all, the absorption rate of calcium in the small intestine of the human body is different at different times: usually the intestinal absorption rate of dietary calcium for adults is about 40%; children and pregnant women can absorb up to 50% or 60%; the elderly are only 20% to 30% or less. Vitamin D promotes intestinal calcium absorption, and its main source is the skin’s own synthesis after receiving light, but the ability of the elderly to synthesize vitamin D in the skin is only 30% of that of young people, and the lack of light, vitamin D can not meet the physiological needs. Secondly, the maintenance of bone morphology and mechanical properties depends on the dynamic balance between bone formation and bone destruction. In old age, bone destruction is greater than bone formation, and bone calcium loss leads to osteoporosis. Therefore, calcium supplementation in the elderly is only a “basic measure” to prevent osteoporosis. If the balance between bone formation and bone destruction cannot be maintained, more calcium will be lost!