“Inhibition of iodide uptake (IUI),” as this effect is called, is a routine occurrence, caused by a number of factors in our diet and environment. The body naturally compensates if the thyroid can’t absorb its normal amount of iodide from the bloodstream. The thyroid itself has an enormous iodide reserve and can open additional “channels” to let more iodide in if needed. Most Americans eat a diet with more than twice the daily need for iodide.