Is a disease of bones that includes an increased risk of fracture. The disease is stated when the mineral density of the bone (BMD) is significally reduced. To be spesific when a bone mineral density is 2.5 standard deviations or more below the mean peak bone mass (average of young, healthy adults) as measured by DXA.
Osteoporosis is an increasing health concern and to prevent it you'll have a few main things you can do. First: Quit smoking. Smoking greatly builds up the risk of osteoporosis. Second: Exercise. This increases the bone density. Third: Get enough the mighty vitamin D. It stimulates the absorption of calcium and therefore strenghtens your bones.