Researchers have evaluated an increasing popularity for patients to self-prescribe and treat with over-the-counter iodine supplements, and the potential of negative outcomes for some patients.
In one case, a 63-year old woman suffered from 15 hours of atrial fibrillation, and was found to have a high iodine levels from self-administration of iodine, along with a Thyroid Stimulating Hormone (TSH) level of less than .006 . After a week on a low-iodine diet, her heart rhythm returned to normal, and her thyroid normalized.
In another case, a 38-year old woman who was experiencing fatigue had a TSH measured at 3.6, and her Thyroid Peroxidase Antibodies (TPOAb) were 1910. She started taking Iodoral iodine/iodide tablets for three months, and when rechecked, her TSH had increased to 94, her thyroid had enlarged -- going from from 30 grams to 50 grams -- and her antibodies had risen to 4670. After stopping Iodoral, the woman went on a low-iodine diet, and took thyroid hormone replacement medication, and her thyroid returned to normal.
In a third case evaluated, a 35-year old woman with Graves' disease was treated with the antithyroid drug propylthiouracil (PTU), as well as the beta blocker atenolol. She started taking over-the-counter iodine for three months, and returned to severe hyperthyroidism. After starting a low-iodine diet and increasing the doses of PTU and atenolol, her thyroid normalized.
According to the researchers, "iodine excess has multiple effects on the thyroid gland, including Jod-Basedow's and Wolff-Chaikoff effects." These iodine-induced thyroid dysfunctions can sometimes be completely reversed, but in some cases they are only partly reversible." The researchers conclude that all patients with thyroid disorders should be counseled on over the counter use of iodine.
The message for patients: While iodine is essential for proper thyroid function, too much can be a trigger for worsening thyroid conditions. Work with an experienced practitioner to evaluate your iodine levels, and don't supplement with iodine unless you know you need it.
- Iodine and the Thyroid
- The Iodine Controversy: Too Much vs. Not Enough, and What It Does To Your Thyroid