Iodine

Importance of iodine in the body:

Iodine is used by your thyroid gland to help regulate metabolism and development of both skeleton and brain, among other things.

(May 4, 2013) How Iodine Defficiency May Affect Functions. Referenced from: http://articles.mercola.com/sites/articles/archive/2013/05/04/iodine-deficiency-affect-childs-brain-function.aspx