This might help explain the role of Iodine in autoimmune thyroid disorders. This is from Dr. Brownstein's book (as posted by Stephanie over at the yahoo group).
THE UNDERLYING CAUSE OF AUTOIMMUNE THYROID ILLNESSES: Iodine DEFICIENCY AND ANTIOXIDANT DEFICIENCY
As previously mentioned, the oxidation of Iodide to Iodine occurs through the interaction of H2O2 (Hydrogen-Peroxid) and TPO. Iodine is a necessary product in order to provide the correct molecule in the cell so that organification can occur. If organification does not take place or is blocked, thyroid hormone and iodo-lipids will not be formed. As can be seen from Figure 3, this reaction is controlled by intracellular calcium levels and iodinated lipids—δ-iodolactone.
Intracellular calcium stimulates this pathway. On the other hand, δ-iodolactone and other iodinated lipids act as a brake on the system. If there is not enough iodine in the cell to organify and produce adequate amounts of δ-iodolactone, it can set the stage for damage to the thyroid cell and the development of an autoimmune thyroid disorder such as Hashimoto’s or Graves’ disease.
A Proposed Mechanism For The Development Of Autoimmune Thyroid Disorders
The NADPH oxydase system is found in the mitochondria of our cells. The mitochondria are the energy-producing cells of our body. The mitochondria produce energy (i.e., ATP) through a complex process called oxidative phosphorylation. All medical students (and most physicians) are familiar with oxidative phosphorylation because we have to memorize the many steps responsible for producing ATP. This production of ATP requires many items including: oxygen, magnesium, ADP, and amino acids.
Many people with chronic illnesses, such as fibromyalgia, chronic fatigue syndrome, and autoimmune disorders, complain they have no energy. ATP is the molecule that stores energy for the body. The body is constantly producing and utilizing ATP. Its production is a complex process that is beyond this book. However, there are two cofactors, Vitamins B2 (riboflavin) and B3 (niacin), that are integral to stimulating oxidative phosphorylation and ATP production.
Hydrogen peroxide is a byproduct of oxidative phosphorylation. It is this production of hydrogen peroxide that is so critical to the oxidation process of iodine. Hydrogen peroxide and TPO help to oxidize Iodide to form iodine.
If there is a deficiency in iodine, which is common when ingesting the RDA for iodine, there will not be enough substrate (i.e., iodine) to produce iodinated lipids. As can be seen from Figure 3, the lack of δ-iodolactone and other iodinated lipids results in a loss of the ‘brake’ in the pathway to oxidize iodide. This may result in a temporarily production of too much hydrogen peroxide. This excess hydrogen peroxide can damage the enzyme TPO.
What Happens If TPO Is Damaged? Autoimmune Thyroid Illness
The body’s response to TPO damage is to produce antibodies against TPO or anti-TPO antibodies. A diagnosis of Hashimoto’s disease requires the presence of anti-TPO antibodies. As the damage worsens, surrounding proteins can also be damaged such as thyroglobulin. Damaged thyroglobulin will result in the body producing antibodies against thyroglobulin—anti-thyroglobulin antibodies.
In most cases of Hashimoto’s disease, there are antibodies to both TPO and thyroglobulin present. Although Graves’ disease may also possess these same antibodies, antibody production is not necessary to make the diagnosis of Graves’ disease. However, my clinical experience has shown that the treatment for both Hashimoto’s and Graves’ disease can follow a similar course with similar positive outcomes.
How to Treat Autoimmune Thyroid Disorders
1. Ingest enough iodine in order to provide adequate substrate to iodinate lipids.
2. Take Vitamins B2 and B3 in amounts necessary to stimulate the NADPH system to produce adequate amounts of H2O2.
3. Correct oxidant stress in the thyroid gland and the mitochondria with antioxidants.
4. Ensure adequate magnesium levels.
5. Minimize oxidative stress in the body.
From what I understand small amounts of iodine start the oxidative process but do not create enough iodinated lipids to put a brake on the oxidation process. Thus too much hydrogen peroxide is created causing damage to the TPO enzymes. Stephanie over at Yahoo stated that it wasn't until her husband who has Hashi's went to 50 mg that he saw a reduction in his antibodies. With all that said, I'm sure there are some people for which this doesn't work as we are not all one size fits all-I guess the only way to know it to try it. Diane