And for those of us who take iodine regularly, we are hearing a lot of mis-information that is a disservice to those who are trying to know what is best for their own health and that of their families.
So I will start with some basics. Iodine is a nutrient. It occurs as a mineral (iodine), and as various mineral salts, such as potassium iodide (KI). Your body uses both of these forms. The thyroid gland has an affinity for KI, the rest of the body tends to use the iodine. You need both forms. Every cell in your body contains iodine.
Radioactive iodine can be taken up by the body and "used" in the same fashion as potassium iodide, which means it will collect in the thyroid if it can. What can prevent it collecting in the thyroid is having the thyroid already well stocked with healthy KI. The radioactive iodine will have nowhere to 'park' so it will leave.
There are other things that can mimic iodine and KI, such as bromine. If your iodine receptors are blocked with bromine, which is not an uncommon problem, you will not be able to use the iodine your body needs. This can lead to problems such as malfunction of organs such as the thyroid, breast and prostate.
According to doctors familiar with iodine, most people in the US (and I suspect Canada) are deficient in iodine. Our bodies use about 12.5mg of iodine a day just for normal function. Relying on your iodized table salt for that much iodine would mean eating a great deal of table salt. The Recommended Daily Allowance for iodine is 150mcg (0.15mg).
Some risks of being iodine deficient are: 1) Mental retardation. If a pregnant mother is deficient, her off-spring could be born with a mental deficiency and/or congenital hypothyroidism. 2) Hypothyroidism. If you do not get iodine into your thyroid, it will not function well. 3) Goiter...a swollen or lumpy thyroid. It is because of goiter that iodine was first considered to be added to table salt.
Unfortunately absence of goiter is not a sign of sufficient iodine intake.
Many people take Lugol's Solution, or its solid counterpart, Iodoral. One drop of Lugol's 5% contains about 6.25mg (not mcg) of iodine. The usual Iodoral tablet contains 12.5mg. I know of many people who take far more than one or two drops or tablets a day. For a long time. And are very happy to continue doing so. Thyroids have been brought to better function. Cancers have been cured. Adrenal glands hav been brought to better form.
I found this article. It's a study from 1947, not long before Lugol's solution and iodine became demonized by the medical profession Effects of increased iodine absorbtion