[Bone and calcium metabolism in menopause transition].

Menopause, or estrogen deficiency, predispose women towards fragility fractures resulting from impaired bone strength, as the composite consequence of : (1) increased bone resorption caused by proliferation and activation of osteoclasts ; (2) dissociation of coupling bone formation with resorption ; (3) deterioration of bone quality ; (4) decreased calcium absorption from intestines and resorption from renal tubules. The current explanation of each phenomenon is described in this article, although the exact mechanisms have not been unanimously defined.