Elderly people can take some dietary measures to prevent osteoporosis. Firstly, consume foods rich in calcium, such as milk, yogurt, cheese, and leafy green vegetables. Secondly, vitamin D helps calcium absorption and can be obtained through sunlight exposure and eating fish, egg yolks, and other foods. Additionally, adequate protein intake is important, but avoid excessive amounts as it may increase calcium loss. Finally, reduce the intake of caffeine and alcohol, as they may affect bone density.