Effectiveness of Selenium Supplementation in the Treatment of Graves–Basedow Disease: A Scoping Review

Background: Graves–Basedow disease (GBD) is an autoimmune thyroid disorder characterized by loss of tolerance to the thyrotropin receptor, with clinical manifestations such as a hyperadrenergic state, goiter, orbitopathy, and myxedema, inter alia. Selenium is a micronutrient, essential for the synthesis of selenoproteins. Selenium deficiency has been linked to an increased risk and exacerbation of GBD and GBD orbitopathy; therefore, it has been suggested that supplementation with this micronutrient could modify some outcomes associated with both conditions. Objectives: The objective of this scoping review was to synthesize and analyze the clinical trials that have evaluated the effectiveness of selenium on different outcomes in patients with GBD or GBD orbitopathy. Methods: The following databases were consulted: PubMed/Medline, Scopus, Biosis, ProQuest, Web of Science, and Google Scholar; and the search terms ‘Graves-Basedow disease’ or ‘Graves’ disease’ or ‘hyperthyroidism’ or ‘Graves’ hyperthyroidism’ or ‘selenium or selenium supplementation’ and ‘effectiveness’ were used. The search was limited to articles published in English between January 2000 and March 2025. To reduce selection bias, each article was reviewed independently by three authors using the Rayyan web tool and the JBI Critical Appraisal Checklist. Results: A total of 15 studies were identified (11 on patients with GBD and 4 on patients with GBD orbitopathy). In GBD, selenium supplementation was associated with significant improvements in TSH, FT4, FT3, TPOAb, TgAb, and TRAb levels; while in GBD orbitopathy, a positive effect of selenium supplementation was found on multiple clinical outcomes. Conclusions: Selenium supplementation in patients with GBD or GBD orbitopathy is associated with favorable biochemical and clinical outcomes.