Eligible women consenting to be randomized to the core MAP.3 trial will be approached for participation in this companion study. They must have an acceptable quality BMD scan by DEXA taken within 12 months prior to randomization to MAP.3. A BMD T-score > -2.0 SD (i.e. 2.0 standard deviations below the average peak BMD of a young adult woman) has been established as the study population cut-off because postmenopausal women who have BMD T-scores as low as or lower than - 2.0 SD are currently recommended to consider pharmacological therapies for their bones