This is an interesting article on iodine which discusses possible mechanisms by which iodine deficiency can cause autoimmune thyroid disorders.
My daughter's iodine level was tested and she has only 20% of the minimum level, despite RDA level supplementation in a multivitamin. She has all the common symptoms of Hypo (but no diagnosis) with extreme fatigue (ATP test also very low, private doctor was surprised she could get out of bed). She is currently supplementing and is already seeing an improvement in her energy levels and other symptoms.
My understanding is that Iodine supplementation should only be done under medical supervision and where there is a known deficiency.
As iodine is essential for thyroid function, why are neither GPs or Endos testing for it?