One thing I learned from studying the Edgar Cayce readings for years and endeavoring to put them into practice in my life is this:
Everyone is different. Edgar Cayce , for example, would tell everyone in the world that they would be better off not eating beef, but there would be that one person who should eat some beef.
As far as Iodine goes, some people he recommended kelp for, others Atomidine.
Another thing I learned from Cayce: He said every one of us should learn to be our own "psychic," to learn to listen to the inner voice and follow its guidance.