This pilot project will enroll women with a history of breast cancer who have no evidence of current disease and experience aromatase inhibitor-associated musculoskeletal symptoms in a double-blind randomized clinical trial. The trial will compare vitamin D3 supplementation at the RDA of 600 IU/day (Control group) to the upper tolerable, safe level of 4,000 IU/day (Experimental group). Both groups will also receive 500 mg calcium carbonate per day. The specific aims of the project are to determine the efficacy of vitamin D3 in reducing musculoskeletal symptoms by comparing the change in symptoms from baseline to 6 months in women who are in the experimental group as compared with the usual care control group, to determine whether supplemental vitamin D3 improves adherence to aromatase inhibitor treatment, and to measure changes in circulating sex hormone levels and serum aromatase inhibitor concentration in both groups during the trial.
The Oncology Research Team at Park Nicollet Health Services and the University of Minnesota is comparing two doses of vitamin D3: the current recommended daily allowance (600 IU/day) and the known upper safe level (4,000 IU/day). The are trying to determine whether higher daily doses of vitamin D3 reduce musculoskeletal pain better than the standard daily dose and make it easier for women who have musculoskeletal pain to stay on an aromatase inhibitor for a longer period of time. They are also comparing changes in estrogen levels, bone density, and body composition between the two groups. The researchers wanted to enroll up to 150 volunteers near St. Louis Park, Minn, and the Army of Women (AOW) was one of their sources of recruitment. The Call to Action for this study was sent to AOW members on May 2, 2012, and the researchers closed enrollment on April 4, 2014. The AOW provided them with 27 women who were interested in enrolling in the study.