This is a 2-year, randomized, double-blind, calcium/vitamin D-controlled clinical trial of a single dose of therapy with at least 12 months follow-up. All participants will receive calcium and vitamin D throughout the trial. At baseline, 190 women will be randomized in a 1:1 allocation to zoledronic acid (group 1) or zoledronic acid placebo (group 2). At the end of 24 months, women will be followed to gather data on longer term fragility fracture rates and survival until all participants have completed 24 months of follow-up.