About 5 years ago, I was diagnosed with multinodular goiter, a different thyroid problem. About the same time I was experiencing the symptoms of an under active thyroid. However, my bloodwork is normal. I see my PCP about once per year to have my thyroid and bloodwork checked. My PCP believed that I will eventually need synthetic hormone. I am hoping with diet I will be able to avoid having to take any meds.
When I was diagnosed with goiter, I started looking around on the internet to find out what could have caused it, and I learned that soy does affect thyroid function. So I tried to avoid it as much as possible. I also learned about goitrogens (foods that can supressthyroid functon and cause goiter- brussel sprouts, kale, broccolli,etc), and tried my best to avoid those as well. Since I have gone raw, the soy isn't a problem, but I have been eating a lot of kale and cauliflower.
Anyway, here is a link that I had bookmarked about food, medication, and suppliments and how they affect your thyroid.
http://thyroid.about.com/gi/dynamic/off ... ug-faq.htm
And here is one that talks about goitrogens (and lists soy as one):
Good luck with getting your med. dose correct