Hi, I'm really no expert, however, I have problems with low thyroid, but I have normal blood tests and normal ultrasounds of my thyroid. I have made posts on another website and found that even if you are in normal range, the TSH and Free T4 may be out of proportion to one another.
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Also, I checked my Prescriptions for Nutritional Healing book (Balch) and it had this to say about selenium. "Selenium's principal function is to inhibit the oxidation of lipids (fats) as a component of the enzyme glutathione peroxidase. It is a vital antioxidant, especially when combined with vitamin E. ...Selenium plays a vital role in regulating the effects of thyroid hormone on fat metabolism. ...Symptoms of excessively high selenium levels can include arthritis, brittle nails, garlicky breath odor, gastrointestinal disorder, hair loss, irritability, liver and kidney impairment, a metallic taste in the mouth, pallor, skin eruptions, tooth loss, and yellowish skin. ...Taking up to 200 micrograms of selenium per day is considered safe for most people. However, you should not take more than 40 micrograms of supplemental selenium daily if you are pregnant."
Have you checked into Wilson's? I think this is what I have. http://www.wilsonsthyroidsyndrome.com/
Good luck and will you share back anything you find success with.