Processed salt has all the good stuff taken out so they have to put some of it back in. Natural Sea Salt like Celtic Sea Salt is rich with natural iodine, but for the ultimate sea source of Iodine and everything else you need check out Ocean Plasma at http://www.oceanplasma.org I discovered this in the course of doing research on natural healing: http://www.truthquest2.com and after trying it myself I'm passing the word along.