LAUSR

ed with methimazole and levothyroxine, according to the block-and-replace regimen. In another recent randomized clinical trial performed in selenium-sufficient patients, we did not observe a beneficial effect of selenium in patients with Graves hyperthyroidism treated with methimazole, in terms of short-term, prompter control of thyroid hyperfunction [5] . Based on the combined results of these two studies, we believe that selenium supplementation might be offered to patients with Graves hyperthyroidism only if selenium deficiency is documented. Concerning Graves orbitopathy (GO), there is clear-cut evidence for a beneficial effect of selenium derived from a large randomized clinical trial performed by the European Group on Graves Orbitopathy (EUGOGO) in patients with mild GO [6] . Therefore, as suggested by the recently published EUGOGO guidelines on GO [7] , a 6-month course of selenium can be offered to patients with mild GO. In the EUGOGO study serum selenium levels were not measured [6] . Therefore, it is not known whether the use of selenium should be restricted to patients with a proven selenium deficiency, which remains to be investigated. It may be argued that there is only one study supporting the use of selenium for Dear Editor, In the September issue of the European Thyroid Journal , Negro et al. [1] reported on a survey carried out among members of AME (Associazione Medici Endocrinologi) and AACE (American Association of Clinical Endocrinologists – Italian Chapter) on the use of selenium in thyroid disease. Both Negro et al. [1] and, especially, Hegedüs et al. [2] , in the accompanying Editorial [1, 2] , underscored the abuse of selenium in thyroid disease. There is no question that the use of selenium in autoimmune thyroiditis, as a measure to prevent the development of hypothyroidism [3] or to provide a benefit in patients already receiving levothyroxine, is not supported by unequivocal evidence. In this regard, prospective, possibly randomized, studies are needed, and we agree that selenium should not be given to patients with autoimmune thyroiditis until evidence for a beneficial effect is convincingly provided. Concerning Graves hyperthyroidism, in our opinion there is some evidence supporting a possible use of selenium as an adjuvant measure in selenium-deficient patients treated with antithyroid medications. Calissendorff et al. [4] conducted a randomized clinical trial in which selenium was shown to provide a beneficial effect in terms of control of hyperthyroidism in a cohort of selenium-deficient patients treatReceived: November 21, 2016 Accepted after revision: January 16, 2017 Published online: March 1, 2017