Actually it has been found that a lot of adults and children are deficient in iodine...it was on tv not long ago. The RDI is not huge though, its just that a lot of people don't seem to eat the foods with iodine in them - and most of the salt you can buy at the supermarket is not iodised, you have to check the label closely to make sure it is. Seafood is another good food for iodine.