Iodine as a potential endocrine disruptor-a role of oxidative stress

[helvella]

Am somewhat surprised by this substantial paper on iodine - deficiency and excess are both addressed. As well as protection from radioactive iodine.

They claim: Universal awareness that iodine is a potential EDC would make consumers more careful regarding their diet and what they supplement in tablets, and-what is of great importance-it would make caregivers choose iodine-containing medications (or other chemicals) more prudently.

Which seems somewhat optimistic given the position of some iodine advocates and takers.

Endocrine. 2022 Jun 20.

doi: 10.1007/s12020-022-03107-7. Online ahead of print.

Iodine as a potential endocrine disruptor-a role of oxidative stress

Małgorzata Karbownik-Lewińska 1 2 , Jan Stępniak 3 , Paulina Iwan 3 , Andrzej Lewiński 4 5

Affiliations

• PMID: 35726078

• DOI: 10.1007/s12020-022-03107-7

Abstract

Purpose: Iodine is an essential micronutrient required for thyroid hormone biosynthesis. However, overtreatment with iodine can unfavorably affect thyroid physiology. The aim of this review is to present the evidence that iodine-when in excess-can interfere with thyroid hormone synthesis and, therefore, can act as a potential endocrine-disrupting chemical (EDC), and that this action, as well as other abnormalities in the thyroid, occurs-at least partially-via oxidative stress.

Methods: We reviewed published studies on iodine as a potential EDC, with particular emphasis on the phenomenon of oxidative stress.

Results: This paper summarizes current knowledge on iodine excess in the context of its properties as an EDC and its effects on oxidative processes.

Conclusion: Iodine does fulfill the criteria of an EDC because it is an exogenous chemical that interferes-when in excess-with thyroid hormone synthesis. However, this statement cannot change general rules regarding iodine supply, which means that iodine deficiency should be still eliminated worldwide and, at the same time, iodine excess should be avoided. Universal awareness that iodine is a potential EDC would make consumers more careful regarding their diet and what they supplement in tablets, and-what is of great importance-it would make caregivers choose iodine-containing medications (or other chemicals) more prudently. It should be stressed that compared to iodine deficiency, iodine in excess (acting either as a potential EDC or via other mechanisms) is much less harmful in such a sense that it affects only a small percentage of sensitive individuals, whereas the former affects whole populations; therefore, it causes endemic consequences.

Keywords: Endocrine disruptor; Free radical; Iodine; Oxidative stress; Thyroid.

pubmed.ncbi.nlm.nih.gov/357...

Full paper open access here:

link.springer.com/article/1...

[Lalatoot]

Thanks helvella . Good to know I'm a sensitive individual! It was overdosing inadvertently on iodine for 4+ years that disrupted my thyroid. I went overactive.The message from me is DON'T TAKE A MULTIVITAMIN OR WELL-WOMAN OR OVER 50s CONCOTION because they are not good for your health.

[Serendipitious in reply to Lalatoot]

I’ve just checked Wellwoman over 50. I don’t see any iodine listed:

vitabiotics.com/products/we...

Or did you have a separate iodine supplement? How much were you taking?

[helvella Administrator in reply to Serendipitious]

I agree. But I suspect Lalatoot was expressing herself meaning "multivitamins and products aimed at women, especially those over 50" as a general descriptor - rather than specifically the product you linked to.

Many multivitamin products are still less than ideal, though. For example, B12 and C should not be taken together.

[Lalatoot in reply to Serendipitious]

@helvella is right - that was a general descriptor. I didn't even know Wellwoman without the hyphen was a brand. I suspect what I was using over 4+ years is no longer available. It was a multi-vitamin aimed at over 50s women from a high street purveyor of such things. You have to understand that this was nearly 20 years ago. The multi gave you 100% of your daily iodine intake amongst all the other vitamins. I am a big fish and shellfish eater and had a normal balanced diet so was not needing the additional 100% iodine.