Iodine

[Tanyaking]

Could someone help me understand why some people take iodine for their thyroid please?

Thank you

Tanya.

[helvella Administrator Thyroid UK]

In an otherwise healthy person, insufficient iodine intake could, indeed would eventually, lead to hypothyroidism. Quite simply, thyroid hormones contain significant quantities of iodine and if there is not enough the thyroid cannot manufacture sufficient.

Worldwide, iodine deficiency is the leading cause of hypothyroidism as so many countries, with such large populations, do not have sufficient in their diets.

It is important to realise that the human body is very efficient at recycling iodine so the amount required is to keep topping it up. That is, to replace what is excreted.

However, to go from that fairly basic observation to assuming that all who are hypothyroid need additional iodine is false reasoning.

The starting point is that someone without a thyroid, or with an impaired thyroid, will be unable to produce sufficient thyroid hormone even if there is plenty of iodine available.

Then the fact that something like 67% of the weight of T4 (levothyroxine) is iodine so anyone taking thyroid hormone is already to some extent supplementing with iodine.

And that iodine can act as an anti-thyroid substance and reduce thyroid hormone production. It is expressly used for this purpose in some approaches to hyperthyroidism treatment.

There are so many rumours and falsehoods surrounding iodine and thyroid it can be very difficult to get to the reality. (And I am most certainly not immune to making mistakes and misunderstandings.) For example, we see people claim that the Japanese consume vast quantities of iodine, from seafood including seaweed, and therefore have virtually no thyroid disease. Some of the higher quotes of iodine intake are unfeasibly high. And there is quite a lot of thyroid disease in Japan.

Our understanding of iodine is still incomplete. Some bits are very well researched but the full picture is not entirely clear. Further, applying the science to the individual is not trivial.

[MaisieGray]

Without in anyway being facetious, I'd say the answer to your question is perhaps because some accept the recommendations of people such as Brownstein, who urge they should. However, in one pro-supplement with iodine article of his, he cautions that people should nevertheless consume unrefined salt when supplementing with iodine because "unrefined salt helps the body safely detoxify from the toxic halides bromine, chlorine and fluoride that can be released when iodine is taken"..... A different source advises that because of "the chemical similarity between iodine and bromine and fluorine, the latter two can apparently mimic iodine in the body, binding to its receptors, and blocking the body’s uptake of iodine". As you'll know, iodine is a key component of thyroid hormones (evidenced in the name of T4 - tetraiodothyronine - and T3 - triiodothyronine - for instance). So rightly or wrongly, my decision for me, is that I've always taken his advice with a pinch of salt too.

[helvella Administrator Thyroid UK in reply to MaisieGray]

Of course, salt (as in common salt) is sodium chloride.

The halogens, in order of the periodic table, go fluorine, chlorine, bromine, iodine - then the ignorable astatine. For most purposes, the similarities are greater the closer they are. So I continually struggle with the idea of taking more chlorine (in the form of a chloride) while demonizing fluorine.

(It is also annoying how so many who claim understanding flip between the element name and the ionic form. Chlorine in elemental form, and in many organic compounds, can be extremely toxic. Whereas chloride - the anion - is a fundamental essential.)