Osteoporosis is a common side effect after endocrine therapy for breast cancer. To prevent osteoporosis, it is recommended to consume foods rich in calcium and vitamin D, such as dairy products, leafy green vegetables, and fish. Also, moderate sun exposure and regular weight-bearing exercises like walking and light training can help maintain bone health. If osteoporosis symptoms have already appeared, doctors may recommend medication such as bisphosphonates. Regular bone density tests are also important to monitor bone health.