The effect of vitamin D supplements on the severity of restless legs syndrome.

Purpose: Clinical observation hinted improved symptoms of restless legs syndrome (RLS) after vitamin D supplements. Hence, the aim of this study is to evaluate the effect of vitamin D supplementation on the severity of RLS symptoms.

Methods: Twelve adult subjects diagnosed with primary RLS and vitamin D deficiency were recruited. Patients with secondary RLS were excluded from this study. The complete cell count; serum levels of ferritin, iron, glycated hemoglobin, and vitamin D3 (25 (OH) vitamin D); and renal and bone profiles of the patients were assayed. Patients with vitamin D deficiency (<50 nmol/l) were treated with vitamin D3 supplements (high oral dose or intramuscular injection). The severity scores of RLS were reassessed after the vitamin D3 level was corrected to >50 nmol/l and compared with those before the administration of the supplements.

Results: The median pretreatment vitamin D level was 21.7 nmol/l (13.45-57.4), which improved to 61.8 nmol/l (42.58-95.9) (P = 0.002) with the treatment. The median RLS severity score improved significantly from 26 (15-35) at baseline to 10 (0-27) after correction of the vitamin D levels (P = 0.002).

Conclusion: This study indicates that vitamin D supplementation improves the severity of RLS symptoms and advocates that vitamin D deficiency is conceivably associated with RLS.