Sea vegetables
The ocean hosts the largest storehouse for iodine foods, including Kelp, Arame, Hiziki, Kombu, and Wakame. Kelp has the highest amount of iodine on the planet and one serving offers 4 times more than a daily minimum requirement. 1 tablespoon of Kelp contains about 2000/mcg of iodine.
Other common foods include.....
Cranberries
Strawberries
Potatoes’ ( skin on )
Soybeans
Spinach
Summer squash
Swiss chard
Turnip greens
Asparagus
Carrots
Tomatoes
Rhubarb
Peas
Mushrooms
All high in iodine content………..:shy:
Dr. Mader's "Reptile Medicine and Surgery" book does not mention discoloration as a sign of iodine issues, but it seems possible that it is an early warning sign of a goiter or inflamed thyroid.
Besides kelp, small amounts of iodinized salt in the diet can help.
Also- review your diet for excessive use of brassicas- cabbage, broccoli, kale, mustard or turnip greens, etc. and replace them with other greens. You don't usually need to avoid brassicas completely, jut make them part of a rotation of good food choices.