My posting on "manganese" gives one a good place to start looking. The lesson is to understand from Dr. Josephson's experiences, that if insufficient manganese and B1 are not present, that thyrotoxicity is the result.
This teaches you that there are things other than "iodine" which have profound impact on thyroid function.
And, how many "professional" endocrinologists are even aware of this, which was known before most of us were even born ? This makes them not as smart as you or me, about something of serious importance, in their own professional field.