We see a lot of people asking about taking iodine in various forms. Sometimes the iodine content of thyroid support products is not obvious.
The following paper (more available by following the link) is of interest.
Some of the authors also wrote the Walter Reed Hospital study on Armour which was so interesting. Desiccated thyroid extract compared with levothyroxine in the treatment of hypothyroidism: a randomized, double-blind, crossover study.
Over-the-Counter Drug-Induced Thyroid Disorders
Thanh D. Hoang, DO, Vinh Q. Mai, DO, Patrick W. Clyde, MD, FACE, Mohamed K.M. Shakir, MD
Objective: Excessive iodine ingestion may cause thyroid dysfunction. In this case series, we report four patients who developed significant thyroid dysfunction after ingesting over-the-counter (OTC) drugs containing large concentrations of iodine.
Methods: Four patients from a tertiary medical center are reported.
Results: Case 1 involved acute exacerbation of thyrotoxicosis induced by taking OTC Tri-iodine TM in a 35-year-old woman while still on methimazole therapy. Case 2 involved thyroid-extract-induced thyrotoxicosis following ingestion of Thyromine TM, and was confirmed by laboratory studies and 131I thyroid uptake. Cases 3 and 4 involved severe, symptomatic hypothyroidism induced in 2 patients with underlying autoimmune thyroiditis (Hashimoto's disease) following ingestion of Iodoral TM. In all cases, thyroid dysfunction resolved with appropriate management and discontinuation of the OTC drugs.
Conclusion: These case reports demonstrate the significant risks associated with OTC preparations containing iodine in patients predisposed to thyroid dysfunction. There is no valid reason for taking high-dose OTC iodine supplements, which have been shown to cause harm and have no known benefit.
Picture is of kelp on a beach in Scotland.