Calcium and vitamin D are the basic supplements for bone health, and the following issues should be noted: ① Calcium: The recommended daily calcium intake for adults is 800 mg (elemental calcium), which is the appropriate dose to obtain the ideal bone peak and maintain bone health. The average daily calcium intake for postmenopausal women and the elderly is 1,000 mg. The average daily calcium intake for the elderly in China is about 400 mg from the diet, so the average daily amount of elemental calcium should be 500-600 mg. When used for the treatment of osteoporosis, it should be used in combination with other drugs. There is insufficient evidence to suggest that calcium supplementation alone can replace other anti-osteoporosis drug therapy. Calcium selection should take into account its safety and efficacy. ②Vitamin D: facilitates the absorption of calcium in the gastrointestinal tract. Vitamin D deficiency can lead to secondary hyperparathyroidism, which increases bone resorption and thus causes or exacerbates osteoporosis. The recommended dose for adults is 200 units (5ug)/d. Elderly people often have vitamin D deficiency due to lack of sunlight and impaired intake and absorption, so the recommended dose is 400 to 800 IU (10 to 20ug)/d. Some studies have shown that vitamin D supplementation increases muscle strength and balance in the elderly, thus reducing the risk of falls and thus the risk of fractures. Vitamin D should be used in combination with other drugs when used for the treatment of osteoporosis. Clinical application should pay attention to individual differences and safety, regular monitoring of blood and urine calcium, and dose adjustment as appropriate.