Iodine is what the thyroid uses to make thyroid hormone. A person who is hypERthyroid should be "AVOIDING" supplemental iodine - not taking it!
However, a person who is LOW on hormone (hyPOthryoid) may need iodine, but rarely do they need extra above what they get in their diet. When you see "thyroid support" websites, they are usually talking about a slow functioning thyroid, NOT Graves disease.
Iodine is also thought to be a trigger for Graves disease.
I've got Graves and I do not take any vitamins with iodine, no seaweed or seafood, no iodized salt. No energy bars (Power Bars, et al), Ensure or Carnation Instant Breakfast (et al), since they all contain lots of added iodine. Some sauces, cream, chocolate milk, salad dressings, even ice cream contain "carageenan" which is seaweed - it's VERY high in iodine. Same with Red Dye 3. All of those should be avoided by a person who has Graves disease (hyPERthyroid).
How Iodine Contributes to Graves' Disease
Iodine is a well-known trigger of autoimmune thyroid disease. As long ago as 1956, Switzerland’s Dr. H. C. A. Vogel explained that the introduction of supplemental iodine to iodine-deficient regions caused a considerable rise in the incidence of Graves’ disease. According to Vogel, in Switzerland, once known for its high incidence of iodine deficiency, Graves’ disease was once unheard of. Vogel noticed many patients troubled by palpitations shortly after iodine was introduced. While the incidence of hypothyroidism caused by iodine deficiency markedly declined, the incidence of hyperthyroidism escalated. Vogel explains that it’s the unnatural formulation of supplemental iodine that causes the problem.
Recent studies by Dr. Nathan Rose of Johns Hopkins University confirm that iodine does indeed cause autoimmune hyperthyroidism in genetically susceptible individuals. Although few patients are ever tested for these antibodies, a significant number of GD patients have antibodies to the iodide symporter mechanism which regulates iodine uptake. Alterations caused by these antibodies may be responsible for the sensitivity of GD patients to iodine. Iodine also triggers thyroid antibody production since thyroid hormone contains approximately 67% iodine.
While most physicians now warn their hyperthyroid patients to avoid iodine, many hidden sources of iodine make this a near impossible feat. Besides iodized salt, iodine is present in many medicines, such as the heart medicine amiodarone. Furthermore, iodine is a component of most multi-vitamin and mineral preparations. Iodine is used in the care and feeding of animals, as a stabilizer, and/or safety element in food processing, and it is a component of food dyes. The richest sources of iodine include kelp, seaweed, iodized salt, dairy products, fish, processed meats, pudding mixes, candies, frozen dinners, “fast” food and foods containing artificial colorings.