Evaluation of Vitamin D Levels in Fibromyalgia Patients and the Relation to Functional Status

Aim: Fibromyalgia syndrome is a common musculoskeletal disorder, characterized by chronic widespread pain, multiple tender points, joint stiffness, and systemic symptoms without any underlying organic disease. The initial aim of the present study was to determine the vitamin D levels in patients with fibromyalgia and compare these values to those found in healthy subjects. Then, correlations between functional status, clinical severity of the disease, and vitamin D levels were assessed. Material and Methods: This case-control study included 137 female fibromyalgia patients and 109 healthy female counterparts. The severity of pain was assessed by a visual analogue scale and the functional impact was evaluated through the Fibromyalgia Impact Questionnaire in the patient group. Vitamin D levels were compared between groups, and the correlation between vitamin D levels and questionnaire scores was determined. Results: Vitamin D and parathormone levels did not differ significantly between groups (p=0.858, p=0.790 respectively). The mean Fibromyalgia Impact Questionnaire scores and the medians for the visual analogue scale did not differ significantly among vitamin D deficient, insufficient, and sufficient patients (p=0.548 , p=0.952 respectively). In addition, no significant correlation between vitamin D levels and the Fibromyalgia Impact Questionnaire score was found(Spearman’s rho=0.056, p=0.513). Conclusion: This study did not show any significant differences between the vitamin D levels of fibromyalgia patients and those of healthy subjects. Further, in fibromyalgia patients, there was no correlation between vitamin D levels and functional status or disease severity