I don't know if anyone with hypothyroidism has read any literature and soy and thyroidism. I have come across a few things on the internet, that have suggested that people with hypothyroidism should not intake soy because of the hormones in it. Supposdly these hormones especially isoflavones can cause underactive thyroid and if you have a thyroid problem it can interfer with medication. Has anyone heard anything on this? From what I understand this seems to be a controversial issue.

Yes! I had borderline hypothyroidism, and I avoided soy and other things that can affect the thyroid, and my last test showed my thyroid was perfectly normal. I am convinced my thyroid healed on its own by avoiding all soy in my diet...

Yes. My RDA says I can have 3 servings of soy products per week and no more. Calcium can also inhibit the absorption of you thyroid medications and you should not have it within 3 hours of taking the meds.

Thank you for your responses. It was insightful

Soy binds with thyroid hormones, making them unusable to your cells. If you have thyroid problems, its a good idea to avoid soy. Fermented soy products, like tempeh, soy sauce, and miso are ok, because the fermentation process destroys the enzymes that interfer with the thyroid. Cooking does NOT destroy it, by the way. There are some good articles on soy and thyroid on about.com's thyroid pages.