Correction

After publication of our work [1], we noticed that the magnesium (Mg) content of the trial tablets was inadvertently given as 250 mg. The correct content was 200 mg. Thus the first sentence under the subtitle "Intervention" should read: The patients received orally for 8 weeks either a daily dose of 400 mg of Mg tablets divided in two tablets (200 mg each) or matching placebo tablets.