Vitamin D3 Effects on Musculoskeletal Symptoms With Use of Aromatase Inhibitors

This project will determine the efficacy of vitamin D3 supplements for reducing side effects of treatment with aromatase inhibitors in women with a history of breast cancer that have no evidence of current disease. The aromatase inhibitors (AI) have become a critical component of adjuvant therapy for this population, but they cause bone pain, joint pain, joint stiffness, and muscle weakness in approximately 40% of patients. These symptoms, referred to as aromatase inhibitor-associated musculoskeletal symptoms (AIMSS), decrease quality of life and medication adherence. Identifying effective ways to decrease these symptoms may allow for longer and more adherent medication use and thus may improve disease-free survival. We hypothesize that vitamin D3 may decrease symptoms associated with the use of aromatase inhibitors.