That's my impression-- Kelp would be the best bet.
I did buy some Lugol's but had a bad feeling about taking it orally. I will keep it in my medicine chest to use topically --but will use the Kelp internally.
I do have SeaAdine (made entirely from Sea Kelp WITHOUT the use of Chlorine in any form in processing) from Cayce's Cures catalog which I feel safe using internally AND topically. In fact, I had a really bad gash on my calf two years ago from walking into a wooded area with old scrap metal sticking out from some dirt.
I probably should have thought about the possibility of Tetanus, but immediately I soaked some cloth with hydrogen peroxide on it-- then when I got home, I dabbed Sea-Adine all over the cut three times a day.
Wouldn't you know it, but within 2 weeks, there was only a fine scar line left behind, and now there is not even a scar! This gash was pretty deep too!
I have childhood scars of lesser past injuries that are still there - but there is no sign of that scar now :-)
I reccomend Sea-Adine for burns-- including facial burns. It is made purely of sea kelp in a tincture form. Like Dennis said, getting the nutrient from a Whole food source is the best-- and face it -- most average folks don't really get kelp in their diet because it's considered a "hippy dippy, trippy" type of healthnut food. Still, Kelp is so full of potassium and other nutrients- including Iodine!
For those who are interested,For about $5.00 a bag, you can get dried kelp to shred into your lettuce salads-- it tastes awesome with olive oil and balsamic vinegar dressing! The company I get from has theirs tested for mercury.
Also- as Dennis said, Black Walnut, etc.. are also good to take