Here is a clinical observation I have witnessed many times, on lab tests, after iodine-iodide supplementation. The TSH will rise and may stay high for weeks to months before coming back down to normal levels.
So, why can the administration of iodine-iodide elevate Thyroid Stimulating Hormone (TSH) levels in those with already high TSH levels or even in those with normal TSH levels?
Iodine from the diet is absorbed throughout the gastrointestinal tract. Dietary iodine is converted into the iodide ion before it is absorbed. The iodide ion is bio-available and absorbed totally from food and water. This is not true for iodine within thyroid hormones ingested for therapeutic purposes. (1)
In the absence of sufficient iodine-iodide, TSH levels remain elevated which reflects the body’s attempt to trap more iodide from the circulation, into the thyroid, to produce thyroid hormones. Again, TSH levels will remain high during supplementation until repletion is completed.
If exogenous (outside) iodine-iodide is supplemented TSH levels may increase by tenths to even double digits. This phenomenon may last for weeks and even for many months. This elevation in TSH will last until the thyroid is repleted with iodine. The chemistry: TSH secretion from the pituitary gland increases thyroid uptake of iodide and stimulates the synthesis and release of T4, primarily, and T3.
Breast, ovarian, prostate, liver, and epidermal tissue have a high affinity for iodide as well. Since the thyroid was depleted of iodine it is logical to assume that other tissues might have some level of iodide deficiency as well. All cells with an affinity for iodide will vie for it once supplemented. When everyone is happy with enough iodide, TSH should move down to normal levels.
The twist: A sodium iodide symporter (NIS) is a channel in the cell membrane of many tissues throughout the body like the thyroid, stomach, salivary glands, intestines, breasts, and ovary. They are for iodide uptake into these tissues. Thyroid-stimulating hormone, prolactin, and oxytocin have all been found to stimulate the making of NIS. While supplementing with iodine-iodide TSH may become elevated in order to facilitate the transport of iodide into the various issues, that require it – thyroid or other.
Note 1: routine TSH levels can be done once a month to track this phenomenon.
Note 2: Breast fibrosis/cysts, ovarian cysts/fibroids, fatty liver disease, and benign prostate hypertrophy, IBS/IBD and many other conditions may improve or resolve during iodine-iodide supplementation
The moral of this story is, do not interpret the elevated TSH number, after iodine-iodide supplementation, as a sign of worsening thyroid function (hypothyroid). Instead, take it as a sign the incredible intelligence of the body is doing its thing and trying to increase thyroid iodide stores.
As a side note, using fluoride toothpaste will create an increased need for iodine-iodide and/or delay the repleting process. Also, make sure to have enough Baja Gold Sea Salt and healthy mono and polyunsaturated fatty acids (PUFA’s) in your diet. Examples are oils found in fish, flax, and olive oil. This helps in carrying iodine/iodide around the body. PUFA’s have two or more carbon-carbon double bonds and iodine loves binding to these over saturated fats like coconut oil.