Effects of vitamin D optimization on quality of life of patients with fibromyalgia: A randomized controlled trial

Background: Numerous studies have been conducted to evaluate the frequency of hypovitaminosis D in patients with fibromyalgia syndrome (FMS) and its association with FMS symptoms. This study aimed at assessing the effect of hypovitaminosis D on the symptoms and quality of life of patients with fibromyalgia. Methods: A total of 74 FMS patients with hypovitaminosis D were randomly assigned into group A (Trazodone 25 mg at bedtime + vitamin D 50 000 IU weekly) and group B (Trazodone 25 mg at bedtime + placebo). Serum vitamin D level, Widespread Pain Index (WPI), Fibromyalgia Impact Questionnaire (FIQ), Pittsburgh Sleep Quality Index (PSQI), and Short Form Health Survey (SF-36) were used at the beginning of the treatment and 4 and 8 weeks post treatment. Results: Significant improvements were observed in WPI, FIQ, and PSQI scores in both groups. Moreover, combination of vitamin D and Trazodone resulted in significant improvement of SF-36 scores compared to Trazodone therapy. Improvement in pain-related indices including the WPI and the physical component score (PCS) fraction of SF-36 was more noticeable in vitamin D/Trazodone combination therapy.    Conclusion: This study suggests that vitamin D supplementation has significant therapeutic benefits in the management of FMS, especially in pain reduction of patients with fibromyalgia. According to our results, a combination of vitamin D supplements and a conventional antidepressant, when given to vitamin D-deficient fibromyalgia patients, could significantly improve both physical and psychological symptoms.