RESUMEN
OBJECTIVE: The role of vitamin D in the etiopathogenesis of fibromyalgia and non-specific musculoskeletal pain is controversial. In our study, we aimed to investigate the effect of vitamin D therapy on quality of life in patients with fibromyalgia. MATERIALS AND METHODS: Seventy patients diagnosed with fibromyalgia and 65 age- and sex-matched controls were included in the study. Patients were grouped as deficient (<20 ng/mL), inadequate (20-30 ng/mL), and sufficient (>30 ng/mL) according to the levels of vitamin D. Vitamin D replacement was performed for patients with deficiencies and inadequacies. Before and after vitamin D therapy, patients filled in the assessment tools, fibromyalgia impact questionnaire (FIQ), Arizona sexual experience scale (ASEX), Beck depression inventory (BDI), visual analog scale (VAS), and short form-36 (SF-36). RESULTS: Vitamin D deficiencies and inadequacies were observed in 60% of the patients (n=42). Among patients with low and normal levels of vitamin D, no statistically significant difference was observed in their values. In scales examined after vitamin D replacement therapy, statistically significant differences were observed in the FIQ, BDI, VAS, and SF-36 compared with pre-treatment. CONCLUSION: Vitamin D deficiency seems to be linked to the pathogenesis of fibromyalgia. Vitamin D supplementation may improve the quality of life in patients with fibromyalgia.