Minimal dosage of iodide required to suppress uptake of iodine-131 by normal thyroid.

Sodium iodide was given in increasing doses to mentally defective children with normal thyroid function. Maximal suppression of iodine-131 uptake was achieved with 1500 to 2000 micrograms of iodide per square meter of body surface per day, but quickly rebounded when iodide was discontinued. This minimal effective dose is important if countermeasures against fallout are employed.