Vitamin D3 Effects on Musculoskeletal Symptoms With Use of Aromatase Inhibitors

Phase 2

Completed

Brief Summary: The Purpose of this study is to determine whether vitamin D3 supplements will decrease the muscle and bone pain that are reported by women who take Aromatase Inhibitors.

Detailed Description: 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.

Recruitment & Eligibility

Inclusion Criteria

Age ≥ 18 years
Women with a history of stage I-IIIa invasive breast cancer
History of hormone-receptor positive cancer (either ER + or PR + or both)
Are prescribed and are taking anastrozole, letrozole or exemestane for at least one month and have at least 7 months of AI treatment remaining
Are experiencing AIMSS

Exclusion Criteria

Unable to read or understand English
History of psychiatric disability affecting informed consent or compliance with drug intake
Malabsorption syndrome or inability to take oral medication
Has less than 7 months of AI therapy remaining

Arm && Interventions

Group	Intervention	Description
Vitamin D3 4000 IU	Vitamin D3	-
Vitamin D3 600 IU	Vitamin D3	-

Primary Outcome Measures

Name	Time	Method
Change in Hand Grip Strength	baseline to 6 months
Change in Musculoskeletal Symptom Sub-scale on the Breast Cancer Prevention Trial Symptom Scale	baseline to 6 months	The MS subscale is a self-reported measure on a scale of 0 to 4, with lower score indicating less arthralgia/myalgia

Secondary Outcome Measures

Name	Time	Method
Average Percent Adherence to Vitamin D Interventio	average for all study ppts for: screening to baseline; baseline to 3 months; 3 month to 6 months	adherence measured with pill counts for the vitamin D at predesignated study timepoints: baseline (after run-in), 3 months and 6 months
Serum Estradiol Concentrations	baseline and 6 months
Vitamin D Binding Protein Genotype	Baseline
Change in PROMIS Physical Functioning Questionnaire	baseline to 6 months	PROMIS measures physical functioning on the short form and higher scores reflect better physical functioning with 10 questions on daily activities of life on a Likert scale ranging from 5 (no problem performing activity) to 1 (cannot do activity). Range on this measure is from 50 (best)-10 (worst).
Whole Body Bone Mineral Density	From Baseline and 6 months of D3 supplementation	GLM Mean and standard deviation of Whole Body Bone Mineral Density (grams/cm2) of Trial Participants by Treatment Arm after controlling for bisphosphonate use
Change in Steady State Concentrations of Serum Anastrazole and Letrozole	baseline to 6 months	Difference in steady state concentrations in plasma from baseline to 6 months