The recommended daily amount of iodine is 150 mcg which are micrograms - you have been taking 75-100 milligrams. This converts to 75,000 micrograms to 100,000 micrograms. This is 500-667 TIMES the recommended daily amount.
Yes, the body needs iodine - this is why it is added to table salt. BUT - it is a very fine line between theraputic doses and overdosing - very very fine line. This is why iodine painting of the feet is a good way to tell when your body has had enough. The body stores 75% of it's iodine in the thyroid and the body only needs about an ounce if it.