Treatment of Thyroid Goiter with Iodine
Decision Algorithm Based on Iodine Status
- The American College of Nutrition recommends against treating goiter with iodine supplementation in iodine-sufficient populations, as excess iodine causes hypothyroidism, goiter, and thyroid autoimmunity in these patients 1
- Measure 24-hour urinary iodine excretion combined with TSH, free T4, and thyroid size assessment to determine iodine status, with normal urinary iodine being 100-300 mcg/24hr 2
Critical Pitfalls to Avoid
- The American College of Radiology recommends considering imaging (ultrasound first-line) to evaluate for nodules requiring biopsy in iodine-sufficient goiters 3
- Patients with autonomous thyroid nodules or longstanding multinodular goiter can develop hyperthyroidism when exposed to iodine excess, due to absent autoregulation in these nodules 1
Non-dietary Iodine Sources to Monitor
- The American College of Clinical Nutrition recommends monitoring non-dietary iodine sources, including iodinated contrast agents for radiologic studies, topical povidone-iodine disinfectants, and amiodarone (anti-arrhythmic drug), which can deliver massive iodine loads causing toxicity 1, 4, 5
- The American College of Clinical Nutrition also recommends being aware that these non-dietary iodine sources can cause toxicity, especially in patients with certain conditions, such as cystic fibrosis or Hashimoto's thyroiditis, who are at high risk for iodine-induced hypothyroidism 2