Miramir Aghdashi - Department of Rheumatology, School of Medicine, Urmia University of Medical Sciences, Urmia, Iran.
Seyedmostafa Seyedmardani - Department of Rheumatology, School of Medicine, Urmia University of Medical Sciences, Urmia, Iran.
Hushyar Azari - School of Medicine, Urmia University of Medical Sciences, Urmia, Iran.
Siavash Miraki - School of Medicine, Urmia University of Medical Sciences, Urmia, Iran.
Ashti Morovati - Department of Biochemistry and Diet Therapy, School of Nutrition and Food Sciences, Tabriz University of Medical Sciences, Tabriz, Iran.

 Fibromyalgia (FM) is a chronic musculoskeletal disorder characterized by widespread, long-term pain and multiple tender points revealed in physical examination. Previous studies about the relationship between serum vitamin D level and FM have reported paradoxical results. This cross-sectional study aimed to evaluate levels of vitamin D and its relationship with the severity of FM. Based on the American College of Rheumatology (ACS) criteria, ۱۰۰ female patients with FM were enrolled in this study, and their serum vitamin D levels were screened. Vitamin D deficiency is defined as a level less than ۱۲ ng/mL; insufficiency is defined as a level between ۱۲–۲۹ ng/mL, and sufficiency is a level equal to or greater than ۳۰ ng/mL. Disease severity was evaluated by symptom severity scale (SSS) score and documented using designed questionnaires. Among the ۱۰۰ female FM patients enrolled in this study, the mean patient age was ۳۵.۶۰ years; ۴۷% of them had vitamin D deficiency, ۳۶% had vitamin D insufficiency, and only ۱۷% had normal vitamin D serum levels. Vitamin D deficiency was reported among ۵۰% of patients with an SSS score between ۹ and ۱۲, ۴۹% of patients with an SSS score between ۵ and ۸, and ۱۴.۳% of patients with an SSS score between ۱ and ۴. There was no significant correlation between patient age and vitamin D level (p-value=۰.۱۲). Moreover, no significant correlation was found between patient age and SSS score (p-value=۰.۳۶). The current study demonstrated that there was no statistically significant relationship between FM disease activity and vitamin Dserum level. 

Deficiency, Disease Severity, Vitamin D, widespread pain