Effects of High-Dose Vitamin D Supplementation on Phase Angle and Physical Function in Patients with Prostate Cancer on ADT

Abstract

Purpose

Androgen deprivation therapy (ADT) is commonly used to treat patients with advanced prostate cancer but is associated with functional decline. Bioelectrical impedance analysis (BIA)-derived phase angle may reflect frailty and functional decline in cancer patients. High-dose vitamin D supplementation may improve phase angle values and physical function.

Methods

We conducted an exploratory analysis from a phase II randomized controlled trial investigating the efficacy of high-dose vitamin D supplementation in prostate cancer patients (age ≥ 60 yrs). Fifty-nine patients were randomized to high-dose vitamin D (600 IU/day plus 50,000 IU/week) or low-dose: RDA for vitamin D (600 IU/day plus placebo weekly) for 24 weeks. Phase angle was measured by BIA. Physical function measures included handgrip strength, 6-minute walk test, Short Performance Physical Battery and leg extension. All testing was completed at baseline, week 12 and week 24.

Results

Phase angle values were wider over the entire study in the high-dose vitamin D arm indicating healthier muscle cells. The low-dose vitamin D arm had phase angle values consistent with frailty cutoffs in older men (<5.7°).

Conclusion

Patients in the high-dose vitamin D arm experienced wider phase angle values over the course of the study which may indicate less frailty. ClinicalTrials.gov ID: NCT02064946.

Acknowledgments

The authors would like to thank all study participants involved in this research.

Disclosure statement

The authors report no conflict of interest.

Author Contributions

J.I. drafted the manuscript, L.P. conducted the original randomized controlled trial, J.I. performed the formal analysis, E.C., I.F., E.W. contributed to the study design and analysis, I.F., P.L., L.P., J.R., and A.S. contributed to writing the manuscript, all authors (J.I., I.F., E.W., E.C., J.R., A.S., P.L., K.M. and L.P.) critically reviewed and approved the final version of the manuscript.

Compliance with Ethical Standards

Conflicts of Interest

The authors have no relevant affiliations or financial involvement with any organization or entity with the subject matter or materials discussed in this manuscript and therefore, have no conflict of interest to declare.

Informed Consent

Informed consent was obtained from all individual participants included in the study.

Ethical Approval

Furthermore, the authors declare that the protocol herein described complies with the University of Rochester Medical Center and that they obtained institutional review board approval and have been performed in accordance with the ethical standards as laid down in the 1964 Declaration of Helsinki and its later amendments or comparable ethical standards.

Additional information

Funding

This study was funded by grants NIH NCI CA175793, NIH NCI T32CA102618 and NIH NCI UG1CA189961.