Researchers from Bern University Hospital and the University of Bern in Switzerland studied 174 patients with chronic pain. Serum 25(OH)D measurements revealed 71% of patients were vitamin D deficient with 25(OH)D levels <50 nmol/L); another 21% had insufficient vitamin D levels with 25(OH)D <75 nmol/L. Researchers found a significant inverse association between continuously scaled 25(OH)D levels and mechanical pain sensitivity, a finding that is in agreement with experimental animal work on provoked pain sensitivity. They concluded that in patients with chronic pain, lowered vitamin D levels are associated with elevated central hypersensitivity, namely increased mechanical pain sensitivity and severity of somatic symptoms. As the prevalence of vitamin D deficiency/insufficiency is high in this population, it may seem good clinical practice to screen for 25(OH)D levels below 75 nmol/L and consider vitamin D supplementation.
Von Kanel, et al. Vitamin D and Central Hypersensitivity in Patients with Chronic Pain. Pain Medicine 2014; 15: 1609-1618