Re: 250mcg to 130 000 mcg (0.25 - 130 mg), depending on who you trust... real nice range, huh? And yet another source says that 1100 mCg is the upper tolerable level.

other warnings: Potassium Iodide - if you see it, DON'T take it. It's a THYROID BLOCKER, used for emergency radiation exposure protection only. It's unhealthy as hell, but lets you withstand larger short-term dosages of radiation for a day after taking it. (it is not in any way shape or form useful for "detox" purposes and will NOT cleanse your body of radiation damage already received)

please read

http://www.optimox.com/pics/Iodine/IOD-02/IOD_02.htm 

Optimum Levels of Iodine for Greatest Mental and Physical Health

http://www.optimox.com/pics/Iodine/IOD-01/IOD_01.htm

The Safe and Effective Implementation of Orthoiodosupplementation In Medical Practice

http://www.optimox.com/pics/Iodine/IOD-05/IOD_05.html#F3

On more :)think it does not hurt :D