Maybe this will help you trying to do your own research. http://www.30bananasaday.com/forum/topics/iodine-supplements
If you live in the United States, iodine deficiency is very uncommon, and it is not necessary to supplement.
Iodine is present in many places of the earth, and in almost all the foods we eat provided they are grown on iodine rich soils. We also need very small amounts of it to stay healthy, and that is like 1/20,000 of a tsp! Iodine is in most of the fruits and greens we eat.
Some of the iodine scares in the media are probably more of a marketing tool used by the table salt industry than an actual need or reality IMHO.
Tnx PK, this is a great explanation.