Background: Restless Legs Syndrome (RLS) is a neurological disorder primarily linked to dopaminergic dysfunction. Since vitamin D plays a role in modulating the dopaminergic system, this study aimed to evaluate the impact of vitamin D supplementation on symptom severity, sleep quality, depression, and fatigue in patients with idiopathic RLS and vitamin D deficiency.

Methods: This study retrospectively evaluated patients with idiopathic RLS and vitamin D deficiency who presented to our clinic between April 2022 and March 2023. Participants received weekly oral supplementation of 50,000 IU vitamin D and were assessed at baseline and at 3 months using the International Restless Legs Syndrome Study Group (IRLS) Symptom Scale, Fatigue Severity Scale (FSS), Beck Depression Inventory (BDI), and Pittsburgh Sleep Quality Index (PSQI).

Results: Twenty-five patients (10 females and 15 males) meeting the eligibility criteria were enrolled. Following vitamin D replacement, mean serum 25-hydroxyvitamin D [25(OH)D] levels increased significantly from 16.91 ± 8.09 ng/mL to 38.08 ± 9.58 ng/mL (p< 0.001). A statistically significant reduction was observed in IRLS symptom severity scores (15.36 ± 6.75 vs. 14.28 ± 6.22, p = 0.019). However, no statistically significant changes were found in FSS, PSQI, and BDI scores (p = 0.058, 0.242, and 0.846, respectively).

Conclusion: Vitamin D supplementation appears to reduce symptom severity in patients with idiopathic RLS and vitamin D deficiency; however, its impact on sleep quality, depression, and fatigue warrants further investigation. Large-scale, randomized controlled trials are necessary to confirm these preliminary findings and define the role of vitamin D in RLS management.

Keywords: depression, fatigue, restless legs syndrome, sleep quality, vitamin D