An Unusual Etiology of Fatigue in a 75-Year-Old Woman

A 75-year-old female patient presented to her primary care provider to evaluate several nonspecific symptoms that had progressively worsened over the preceding 2 months. The patient had a generally noncontributory medical history and initially denied any over-the-counter supplements or new items in her regimen. After laboratory results revealed a suppressed level of thyroid-stimulating hormone and elevated T4, the patient admitted to oral supplementation with several supplements that were not initially reported, including iodine for "heart health" for an unknown amount of time. Thyroid imaging did not reveal any nodules, and the patient's laboratory values and symptoms normalized 12 weeks after stopping supplementation.