Exclusion Criteria: Unable to exercise (e.g. major physical disability, severe osteoarthritis, or other severe comorbidity); severe cardiac disease (congestive heart failure with New York Heart Association (NYHA) class >2, angioplasty/coronary artery bypass surgery within 3 months of study entry); patients with bone endocrinopathy (parathyroid disorders, osteomalacia); stage IV-V chronic kidney disease (estimated glomerular filtration rate [eGFR] <30 mL/min/1.75 m2; prior serum creatinine not required for entry into study); allergy to components of calcium & vitamin D tablets.