An adult has fewer bones than a baby. We start off life with 350 bones, but because bones fuse together during growth, we end up with only 206 as adults.
Taking care of your bones takes more than calcium. You need to perform weight-bearing exercises (not just elliptical or cycling) and an alkaline-rich diet full of vegetables and fruits. Avoid sodas and sugars, which rob your bones of calcium. You've only got 206, so take care of them.