what is the best treatment for osteopenia?
['Bisphosphonates (including alendronate [Fosamax], risedronate [Actonel], ibandronate [Boniva], and zoledronic acid [Reclast])', 'Calcitonin (Miacalcin, Fortical, Calcimar)', 'Teriparatide (Forteo)', 'Denosumab (Prolia)']