Why do bones need calcium?
Short answer
Calcium helps make bones strong and is also needed for nerve and muscle function.
How it works
Calcium salts, mainly calcium phosphate, help make bone hard. Vitamin D helps the body absorb calcium from food, and exercise and age also affect bone health.
Key point
Bone health does not depend on calcium alone. Needs vary with age and sex, so do not increase supplements on your own; ask a health professional.