Factors Associated with Vitamin D Testing, Deficiency, Intake, and Supplementation in Patients with Chronic Pain

Vitamin D deficiency is a public health issue, with reports of six- to twenty-five-fold rise in vitamin D testing. Vitamin D deficiency has been linked to many chronic diseases such as diabetes mellitus, cardiovascular disease, depression, and chronic pain. Identifying factors associated with risk of deficiency in individuals with chronic pain will help minimize time and cost. This study aims to examine the factors associated with vitamin D testing, intake, and physician-advised supplementation in individuals with chronic pain. Using a cross-sectional design, data were collected from 465 individuals with chronic pain. These data were analyzed using penalized logistic regression with the LASSO technique. Fifty-seven percent reported being tested for vitamin D, about 40% reported being diagnosed with vitamin D deficiency, and of those who had been tested, 60% reported taking vitamin D supplementation. The findings suggest older age (OR 3.12, CI [1.02, 9.50]) and higher mean pain intensity score (OR 2.02, CI [1.13, 3.59]) increased an individual's chance of being vitamin D deficient. Unemployment or on leave due to pain (OR 1.79, [CI 1.03, 3.11]), part-time employment (OR 1.86, CI [1.02, 3.39]), and being a resident of Australia (OR 2.32, CI [1.13, 4.72]) increased chances of being tested for vitamin D. Being diagnosed with vitamin D deficiency (OR 6.67, CI [2.75, 16.19]), unemployed or on leave due to pain (OR 3.71, CI [1.25, 11.00]), and in part-time employment (OR 2.69, CI [0.86, 8.38]) were associated with physician-advised vitamin D supplementation. Our results may have practical implications, as identifying pretest risk factors may assist in identifying who is at risk of vitamin D deficiency, whom to test, and when to treat.