Elderly people can prevent and improve osteoporosis by supplementing calcium and vitamin D. Calcium is a key component of bones and can be found in milk, cheese, yogurt, tofu, and green vegetables. Vitamin D helps the body absorb calcium; sunlight is a major source of vitamin D, but it can also be obtained from fish, egg yolks, and fortified foods. In addition to calcium and vitamin D, adequate protein and vitamin K are also important for bone health and can be obtained from lean meat, fish, eggs, and leafy green vegetables. Remember, a balanced diet and regular exercise are key to maintaining healthy bones.