Vitamin D Deficiency Is Widespread in Cancer Patients and Correlates With Advanced Stage Disease: A Community Oncology Experience

Abstract

The purpose of this study was to correlate serum vitamin D levels with potential clinical variables and to determine the extent of vitamin D deficiency in a large, outpatient oncology practice. One hundred ninety-five consecutive patients referred for consultation at a community radiation oncology center from October 8, 2008 to March 17, 2010 had vitamin D levels ordered. Patients who were deficient in vitamin D were treated with replacement therapy. Demographic and medical data were collected prospectively and subsequently analyzed. Pretreatment baseline patient and tumor characteristics were evaluated with respect to vitamin D concentrations. One hundred and sixty patients were analyzed. A total of 74% of patients had 25-hydroxyvitamin D concentrations considered either deficient (<20 ng/mL) or suboptimal (20–30 ng/mL). Replacement therapy raised serum vitamin D levels by an average of 15 ng/mL (95% CI = 11–18, P < 0.01). Lower than median serum vitamin D levels were associated with stage III disease in univariate analysis [OR = 2.6 (95% CI = 1.1–6.2), p = 0.04] as well as multivariate analysis adjusted for age, sex, body mass index, and season of draw [OR = 3.3 (95% CI = 1.1–9.7), P = 0.03]. Three-quarters of patients in our series had suboptimal or deficient circulating concentrations of 25-hydroxyvitamin D. Low serum vitamin D levels, independent of age, sex, and body mass index, predicted advanced stage disease.

ACKNOWLEDGMENTS

The authors would like to thank Ms. Melanie Walker for assistance in data collection. Thomas M. Churilla would like to thank the Commonwealth Medical College for partial financial support during the study.

This work was partially supported by the Commonwealth Medical College in the form of a medical student research stipend.

This study was performed at Northeast Radiation Oncology Center in Dunmore, Pennsylvania, United States.