Your bones give your body its shape, help you move, and support your body. Your bones also help protect your heart, lungs, and brain. Even though your bones feel hard and rigid, bones are living tissues that are constantly rebuilding themselves during your life.

Your bones need calcium, vitamin D, and weight-bearing physical activity to stay healthy and strong. If you don't have a healthy diet full of these bone-building nutrients and don’t get enough of certain kinds of exercise, your bones...