For a healthy strong bones you need sufficient calcium and vitamin d to help absorb calcium.
Poor bones can cause several disease and increase the risk of bone damage.
An adult need 700 mg of calcium a day.
So the good source of Calcium are -
1. Milk , tofu ,panner ,cheese and other dairy products .
2. Soya beans
3.nuts like almonds, cashew , walnuts etc.
4. Spinach contain lots of calcium .
You can also make a drink with spinach.