A Possible Clinical Scenario of Iodine-Containing Supplement Causing Thyroid Dysfunction in Pregnancy

This report presents the case of a 33-year-old female patient with a history of Graves' disease who began using a dietary supplement (containing 150 µg of iodine and other micronutrients) to support conception. There was a laboratory finding of suppressed thyroid-stimulating hormone, high free triiodothyronine, and normal free thyroxine (suggesting thyrotoxicosis) uncovered during an early pregnancy assessment. Her thyroid levels returned to normal after she discontinued the supplement without the need for medical treatment. This case stimulated further review of the literature for the potential risks associated with improper use of iodine-containing supplements without consideration for underlying thyroid conditions and for other possible reasons for this finding.