Look how many orders of magnitude more that bromine is present in body composition than is iodine, as reported here:

http://en.wikipedia.org/wiki/Composition_of_the_human_body

Yet, bromine is not necessary, whereas Iodine is. Obviously, the data used for the result was done on an iodine-deficient, over brominated population, just like all the medical "studies" published in the "literature", which makes the conclusions shaky if attempt is made to extrapolate the results to those who are iodine-sufficient.