Iodine is required for thyroid function, so _no_ Iodine is very bad. Trace amounts form diet may be enough (disclaimer IANADietician), but pretty much all the table salt we buy and use is Iodised.
I've noticed that all the sea salts I see, especially anything that comes in a grinder is increasingly not iodized these days. It's like I have to try and buy regular morton salt in a huge cylinder and not fancy hip salt if I want iodized salt anymore.