It will inhibit the thyroid, only if eaten raw in large quantities.
I regularily eat some raw when I am getting it ready for cooking. I have been taking lugols, max amount 4 drops a day. However in about a week I begin to get overdose symptoms. Burning in the nose and a metalic taste.
I also become very anemic. I have been supplementing with 6 mg of copper, 200 mg selenium and 30 mg zinc. I have for the past week been adding iron. It has been taking a long time to get it back this time - over a week now to begin showing good pink in the gums, and feeling less tired.