I like this article about osteoporosis
The author hits on the basics and what you can do now to prevent this disease.
Some positive osteoporosive prevention steps include:
Exercise – Most definitely get exercise. Your muscles pull and leverage against your skeletal system. If you get decent exercise on a regular basis, it can have the effect of strengthening your bones.
Soft drinks – quit drinking them – the phosphoric acid leaches calcium out of your body. Caffeine does this too. There is a pay back for the boost that comes from ‘energy’ enhancing drinks. Keep this in mind. (Robbing Peter to pay Paul type of thing)
There are drugs available for those who currently have osteoporosis: cyclic etidronate, alendronate, and risedronate. See your doctor for help there.
More complete information on osteoporosis (and a bit technical ) can be found here:
Here is a neat site osteoporosis prevention in girls: