This collectively points at vitamin D as a potential, more natural and safer treatment option for those suffering from RLS. However, the role of vitamin D in RLS has not been effectively investigated. The aim of this 12-week, triple-blinded, randomized, placebo-controlled trial is to confirm the relationship between vitamin D deficiency and RLS and hence elucidate the efficacy of vitamin D replacement therapy in reducing the severity of RLS, with predictions that the results will contribute to better understanding of the disease and its management.