When it comes to the side effects of chemotherapy, many people only notice hair loss and vomiting, but osteoporosis caused by chemotherapy is often overlooked. Researchers have found that ovarian failure caused by breast cancer chemotherapy can lead to severe osteoporosis in the spine and femur within 6 months after the start of the treatment program, so it is recommended to pay attention to the patient’s bone mineral density in order to prevent osteoporosis. Osteoporosis is very common in breast cancer patients, especially in postmenopausal patients taking endocrine therapy. Regular observation and timely supplementation of calcium and vitamin D with medication and food are needed to prevent the serious sequelae of bone loss; in addition, smoking and alcohol should be abstained from, and appropriate exercise and ideal body weight should be maintained. Dietary Calcium Intake: Adequate calcium and vitamin D supplementation can prevent bone loss and minimize the occurrence of bone fracture. Studies show that most people do not consume enough calcium. However, if a large amount of calcium supplementation (≥4000 mg) absorption rate is poor, and low-dose (≤500 mg) and compounded calcium tablets containing active vitamin D supplementation, its utilization rate is better, the recommended daily intake of calcium for adults is 1000 mg; in addition, ultraviolet B (UVB) in the sunlight is the body’s main source of light for the production of vitamin D, it is recommended that every day 15-30 minutes of sunshine; followed by emphasizing the importance of the sunshine; the second emphasis on the appropriate amount of calcium and vitamin D supplementation can prevent bone loss and reduce the incidence of fracture. Secondly, a balanced diet should be emphasized: adequate intake of vegetables, fruits, whole grains and low-fat milk is essential for good health.