my wife was told by a naturopath that she was iodine deficient. She started to supplement with Idone and soon her thyroid was showing suppresion. She is a very lean person and had normal TSH and T4 levels before supplementing and after, she had bllod work done and her levels were off. She stopped the iodine and her levels went back to normal. Here is a quick blurb.
“They found that over time – in a nation that mandates addition of iodine to salt – increased iodine intake was linked to decreased thyroid function. The findings appear in the June 29 issue of The New England Journal of Medicine.”