The main problem with kelp, and mind you content varies, is that kelp can also contain bromine. Bromine, another halogen, can block iodine, defeating the whole purpose. Bromine isn't always high in kelp, and different kelps contain different amounts and this may not even be a problem in many situations. Some people who react to iodine-rich foods may actually be reacting to the bromine. For me, I have to be careful with an existing thyroid issue. I do take a couple of kelp tablets, but I don't want to get the bulk of my Iodine from kelp. Since I also would like to improve my total body Iodine content, I don't want to have to take the number of kelp tablets I would need to get to that amount. I won't maintain the 12+mg suggested, but if I can improve my stores over time, I may be able to reap some of the benefits all the same.