Did you know that you have more than 200 bones? They hold up your body, and, along with your muscles, keep you moving. Basically, without bones you'd just be one big blob!
So, what are these bones made of?
Collagen and calcium work together to make bones strong and flexible. All together, the bones in your body form your skeleton. Your skeleton is very strong, but also very light. Wanna know a cool fact? Most of your body's calcium is found in your bones and teeth!! (The rest is in your blood — weird, huh?)
Besides calcium and collagen, bones also contain water, minerals, and cells that grow and change. Even though bones you've seen may have looked all dried up (think skeletons in movies or museums), yours really live and grow inside you. Bones are always growing and they're strongest by your 20s.
When you're a baby, you have more than 300 bones, but by the time you're an adult you'll only have 206 because some of your bones join together as you grow. To be able to grow, strong bones need lots of calcium and bone-strengthening activity. Find out how calcium and bone-strengthening activity make bones strong.