(HealthDay News) -- Osteoporosis -- caused when the body can't replace bone calcium as fast as it is lost -- is common as people age, particularly among women.

More than 1.5 million Americans each year sustain a bone fracture related to osteoporosis.

Here are common risk factors for osteoporosis, courtesy of the American Academy of Orthopaedic Surgeons:

* Getting older.
* Not doing enough weight-bearing exercises.
* Insufficient estrogen levels after menopause.
* Not getting enough calcium or vitamin D in your diet.
* Certain hormonal imbalances.