There's some kind of ratio too. But I know that too much potassium can be dangerous.
I would also research the co-factors of magnesium if you're taking that much. I know b6 and b12 is part of the mix.
Finally, one poster here said that he doesn't see essential fatty acids mentioned as a co-factor to the Iodine protocol and they are very important. Have to look up the link, I think I saved it. Fatty acids, among other things, form the myelin sheath around nerves.