The relationship between iron status and the restless legs syndrome (RLS) was examined in 18 elderly patients with RLS and in 18 matched control subjects. A rating scale with a maximum score of 10 was used to assess the severity of RLS symptoms. Serum ferritin levels were reduced in the RLS patients compared with control subjects (median 33 μg/1 vs. 59 μg/1, p<0.01, Wilcoxon signed rank test); serum iron, vitamin B₁₂ and folate levels and haemoglobin levels did not differ between the two groups. Serum ferritin levels were inversely correlated with the severity of RLS symptoms (Spearman’s rho -0.53, p < 0.05). Fifteen patients with RLS were treated with ferrous sulphate for 2 months. RLS severity score improved by a median value of 4 points in six patients with an initial ferritin ≤ 18μg/1, by 3 points in four patients with ferritin > 18 μg/1,≤45 μg/1 and by 1 point in five patients with ferritin >45 μg/1, <100 μg/1.

Iron deficiency, with or without anaemia, is an important contributor to the development of RLS in elderly patients, and iron supplements can produce a significant reduction in symptoms.