...Except I have always taken selenium and Iodine together and I still developed Hashi's (high antibodies only) after approximately 2.5 years supplementation (100mg Lugol's, 200-400mcg. selenium. 400-800mg. magnesium, 2g vitamin C, unrefined Sea Salt ).
I did not have any known thyroid issues prior to starting iodine--I took it for female hormonal issues (and it worked beautifully for that so I'm really bummed about the thyroid antibodies--+900 TPO).