Graves’ disease and vitamins

Hi,I had radio active iodine treatment on my thyroid approx 15 years ago , which basically destroyed it and since then take a prescribed dose of thyroxine tablets to make it function normally.  I was always told to check labels and not to take any supplements that have added iodine .  A lot of multivitamins have iodine and of course kelp supplements .  Probably best to check with your doctor as to your own requirements with your thyroid problems and breast cancer.