The effect of a low-iodine diet on remission and quality of life in newly diagnosed patients with Graves’ disease: the ELODI superiority, parallel group randomized controlled trial protocol

Healthcare is in the midst of a paradigm shift in which dietary intake, lifestyle, and patient autonomy play an increasingly central role. Research focuses on prevention and treatment of major noncommunicable diseases through dietary and lifestyle interventions. Thyroid disorders, the second most common endocrine disorders after diabetes and also classified as noncommunicable, have received little attention in this context. With respect to nutrition and lifestyle, it is well known that iodine, being an essential element for the synthesis of thyroid hormones, influences thyroid function. Excessive iodine intake has been associated with the worsening of Graves’ disease, potentially reducing remission rates and increasing medication requirements. Conversely, reducing iodine intake may lower thyroid hormone production and improve treatment outcomes. This protocol marks the start of the ELODI study, in which we will investigate the broader effects of a temporary low-iodine diet in Graves’ disease patients. Primary outcome is remission rate 12 months after discontinuation of anti-thyroid drug therapy upon a low- versus sufficient-iodine-containing diet. Secondary outcomes include assessing effects on autoimmune activity, quality of life, and medication dosage. Other outcomes assessed are gut microbiota profile, lipid profile, Graves’ ophthalmopathy risk, and GREAT + prediction. This is a multicenter, open-label, randomized controlled superiority trial, with four parallel groups of 58 newly diagnosed adult participants. Graves’ disease is mainly treated with medication nowadays and subsequently with radioactive iodine or thyroidectomy if drug treatment fails. Persistent uncertainty about the best available treatment and ongoing symptoms in treated patients support exploring dietary interventions. A low-iodine diet is accessible, empowers patients and may improve long-term remission while reducing medication use and side effects. Challenges include adherence, blinding and standardization. Trial registration: OMON, NL-009585. Registered 4 March 2025, https://onderzoekmetmensen.nl/nl/trial/58211. ICTRP, NL-OMON58211. Registered 4 March 2025, https://trialsearch.who.int/Trial2.aspx?TrialID=NL-OMON58211. This paper is based on protocol version 1.2, October 2025.