Lack of Iodine?

I've read a couple articles recently about the effects created by a lack of iodine in our bodies. Since I don't eat seafood and rarely add iodized salt to my food, I am not partaking in two of the most common ways to get iodine into my system. One of the articles stated that a majority of people tested in the U.S. had far less iodine than they needed, with many having close to zero. One way to test your need is to paint a 2 inch square patch on your inner arm and wait 8 hours. If the color is gone in that span of time, then your body desperately needs iodine. If it is gone in 24, then you still do not have the full amount needed. I've painted my patch and I'll check in the morning.