Vitamin D Levels Are Frequently below Normal in Multiple Myeloma Patients and Are Infrequently Assessed By Their Treating Physicians

Introduction: In addition to breast and colorectal cancers, multiple myeloma has also been associated with vitamin D deficiency. Given the role of vitamin D in calcium absorption and bone metabolism, it is crucial to maintain sufficient levels for multiple myeloma patients because of their high risk of bone-related complications. We hypothesized that there was a high prevalence of vitamin D deficiency and insufficiency among multiple myeloma patients. We also hypothesized that there is inadequate screening of vitamin D levels throughout community oncology clinics nationwide.

Methods: This study both evaluated multiple myeloma patients from a single medical practice specializing in this B-cell malignancy who had a 25-OH vitamin D level determined, and separately determined the proportion of oncology sites that screen for this vitamin among their patients. Charts were reviewed from the medical practice specializing in multiple myeloma, and only the first vitamin D determination was analyzed in the study. Demographics and the presence of the following complications at the time or within 1 year from when vitamin D levels were assessed: peripheral neuropathy, skeletal-related events and bone disease. We defined skeletal-related events as pathological fractures, spinal cord compression or requirement for radiation or surgery, and bone disease as having one of the following: osteoporosis, osteopenia or lytic bone disease.

Patients were categorized as either having sufficient (> 30 ng/ml), insufficient (20 to < 30 ng/ml) or deficient (<20 ng/ml) 25-OH vitamin D levels. Chi square analysis was used to compare the proportion of patients with specific complications to their 25-OH vitamin D levels. To determine the rate of vitamin D screening among community oncologists, Site Information Forms from 508 sites throughout the United States were reviewed which asked these groups whether they screen patients for vitamin D levels.

Results: One hundred sixty-nine multiple myeloma patients were enrolled in the study. Their median age was 67, the mean was 65.4 (range, 38-85) and the gender breakdown was 62% male and 38% female. 25-OH vitamin D levels were sufficient in less than two-thirds (64%) of patients with 22% and 14% of patents showing insufficient and deficient levels of this vitamin, respectively. The proportions of patients with specific complications in relationship to their vitamin D levels are shown below.

Chi square analysis showed no significant differences in complications rates as related to vitamin D levels although skeletal-related events were more frequently observed among patients with vitamin D levels below the normal range (insufficient or deficient). Of the 508 sites that were asked on the Site Information Forms to provide information on whether their physicians assess vitamin D levels as part of their standard of care of their patients, 97% responded that they did not assess vitamin D levels as part of their standard of care of these patients.

Conclusion: Vitamin D levels are frequently low among multiple myeloma patients and, despite this, screening levels of this vitamin is not thought to be part of the routine work up by the vast majority of oncologists in the United States.