I missed a test in your article, by which we can define our levels of iodine.

Iodine patch test: The iodine patch test is a test where doctors paint a patch of iodine on your skin and check how it looks 24 hours later. For those who are not iodine deficient, the patch fades no sooner than 24 hours. But a deficiency will likely cause the iodine to be absorbed into the skin more quickly.

Best regards,
Vincenzo

Distilled water is best for hair wash. Try it!

Thanks for sharing very useful information, bro!

Hey Rob,

Thanks for the comments!

Dr. Brownstein aside — let’s assume that he is wrong on almost everything he says about iodine — we do know that the body (not just the thyroid) needs iodine. And we can reasonably assume that some people do not get the RDA from their usual diet, given that in many places of the world the soil is low in iodine, and some people do not consume iodized salt or iodine-rich foods. (And that is under the conservative assumption that the RDA is actually the optimal amount of iodine we need, because we know that the RDA for many nutrients only represents the bare minimum required to prevent overt deficiency/acute symptoms of deficiency — e.g. rickets from vit. D deficiency or scurvy from vit. C deficiency, or, in the case of iodine, goiter).

Iodized salt was introduced to prevent goiter, but many people nowadays use non-iodized salt, and do not eat iodine-rich foods such as sea plants. We also know that supplementation of the RDA amount of iodine (150 mcg) is very safe and unlikely to cause problems, even in people at risk of thyroid issues, but that it can have significant benefits for those who are deficient (and may not know it) or at risk of deficiency.

NHANES did show a significant decrease in iodine status as measured from urine, and that the 1988-1994 population group had a 4.5-times increase in deficiency compared to the 1971-1974 population: “the median concentration decreased more than 50% between 1971-1974 (32.0+/-0.6 microg/dL) and 1988-1994 (14.5+/-0.3 microg/dL). “Low UI concentrations (<5 microg/dL) were found in 11.7% of the 1988-1994 population, a 4.5-fold increase over the proportion in the 1971-1974 population." (https://pubmed.ncbi.nlm.nih.gov/9768638/)

So, again, I think that advising against taking even small amount of iodine (1 mg per day or less) is dangerous advice, especially in the case of women, who need iodine for breast and reproductive health (not to mention during pregnancy).

Iodine is essential for breast health (https://pubmed.ncbi.nlm.nih.gov/16025225) and has been found to help women who have fibrocystic breast disease: "A review of clinical studies found that iodine replacement therapy (particularly for those with low levels of iodine) may improve the tenderness associated with fibrocystic breast tissue." (Mount Sinai: https://www.mountsinai.org/health-library/supplement/iodine; Ghent WR, Eskin BA, Low DA, Hill LP. Iodine replacement in fibrocystic disease of the breast. Can J Surg. Oct 1993;36:453-460.)

Iodine deficiency is also suspected to be linked with the increased incidence of breast cancer in younger women (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5327366/).

Given the low risk and high potential benefits of low-dose iodine supplementation (in people at risk of deficiency or who are deficient without knowing it, and especially for women), I do think you should revise your recommendation against taking low-dose iodine. You advise people to get most of their iodine from food, but soil levels of iodine vary greatly, thus making the iodine content of foods unreliable (not to mention that we often do not know where our food was grown) — so for most people it is impossible to be certain we are consuming enough iodine, unless they consume sea plants (and we know that some sea plants can contain heavy metals, so a careful selection is needed) or consume enough iodized salt (which people on low-salt diets can't).

So, the only solution to prevent deficiency is to take a (low-dose) iodine supplement. Many multivitamins do include the RDA for iodine (150 mcg), but for people who do not take multivitamins, an iodine supplement — at the very least once or twice a week — provides an insurance against iodine deficiency with minimal risk.

Hey Cristina,

Thanks for reaching out, and for passing along a link to Dr. Brownstein’s website.

I’m always open to revising my opinions – especially in light of new evidence (or evidence to which I was previously not aware). Having said that, I don’t think Dr. Brownstein should be anyone’s go-to resource for iodine.

Here are just a few of the issues I found with Brownstein’s article – specifically his claims and the way he presents information:

1. Brownstein states that he tests his patients for an iodine deficiency using urinary iodine loading tests. According to the article, his source of inspiration for this test this came from reading a doctor newsletter: “Townsend Letter for Doctors and Patients titled ‘Iodine Supplementation Markedly Increases Urinary Excretion of Fluoride and Bromide'”. Iodine loading tests involve having patients supplement with ~50mg/daily of iodine, then measuring urinary clearance of iodine over a 24-hour period. If 90% of that iodine is cleared via the urine during this window, someone is considered iodine replete. If less is cleared, then according to Dr. Brownstein, that person is considered iodine deficient – because much of the uncleared iodine must’ve been taken up by the body. Using this testing methodology, Brownstein cites that 94.7% of the 500+ patients he has tested are iodine deficient. Thus, he implies that iodine deficiency is far more widespread than commonly believed.

Unfortunately, Brownstein doesn’t comment at all about the unreliability of urinary iodine load testing. Ironically, the very publication that inspired Brownstein to begin iodine load testing (Townsend Letters) later published a study demonstrating just how diagnostically useless an iodine load testing actually is. You can read that here. To quote from the text’s discussion:

“Based on iodine loading test results, Abraham estimates that the amount of iodine that can accumulate in the body can reach over 1500 mg once whole body iodine sufficiency is reached.2 The author’s assumption is that the iodine not excreted during the loading test is being held on to and utilized by the body. This might be true if iodine excretion following a 50 mg dose of iodine/iodide only occurred during the 24-hour period of the loading test, which is not the case. Furthermore, iodine is also excreted in feces and sweat, neither of which are accounted for when testing urine.11,12 Iodine excretion in feces could easily be tested to determine the percentage of the 50 mg iodine/iodine loading dose not absorbed by the gastrointestinal tract. Without data on how much iodine is being absorbed, it is impossible to estimate how much, if any, of the iodine that is not excreted in the urine is actually accumulating in the body. A reevaluation of the total amount of iodine retained by the body once it reaches whole body iodine sufficiency is necessary.

In general, a 24-hour collection poses multiple problems, both for the patient and the outcome of the loading test. Missed urine collections and incomplete urine catches during bowel movements can cause significant iodine losses depending on when they occur. A complete collection is needed to accurately determine how much of a 50 mg dose of iodine/iodide is excreted in the urine. Studies have shown that 10% to 20% of 24-hour collections are inappropriately collected or incomplete.15-17Any urine loss during the 24-hour loading test could result in a lower percent excretion and a failed iodine loading test.

In conclusion, modifications need be made to the iodine loading test before it is used to determine whole body iodine sufficiency or a need for supplemental iodine. Currently the iodine loading test does not provide a realistic assessment of an individual’s whole body iodine sufficiency or deficiency due to flaws in the methodology and the use of an arbitrary excretion cutoff point. Extending the iodine loading test’s collection period past 24 hours and including analysis of iodine in feces would provide a better picture of iodine retention after consumption of 50 mg iodine/iodide.”

These data were partly what inspired David Zava, PhD (who focuses on breast cancer research) to write, “Flaws in the Urine Iodine Loading TestCan Lead to High Dose Iodine Therapy and Disrupted Thyroid Function“, where he states that the popularity of iodine load testing arose mostly from “a false premise based on a miscalculation of how much iodine the Japanese consume on a daily basis, which was thought to average 13.8 mg/day1, mostly in the
form of seaweeds known to be high in iodine. However, a more thorough analysis of the literature finds that the Japanese daily consumption is in fact much lower than this, ranging between 1 and 3 mg/day2”.

So, Brownstein is building his argument for widespread iodine deficiency by using a flawed iodine deficiency test – one that generally produces an iodine-deficient result in 90%+ of the people who take it, regardless of their health or iodine status. To me, this isn’t evidence of a widespread deficiency; it’s evidence of an unreliable testing methodology.

2. Brownstein cites an 8-person study as evidence that high-dose daily iodine supplementation can help to “saturate [the body] with iodine while at the same time detoxifying from the toxic halides bromide and fluoride.” This statement is confusing, and for many reasons.

For starters, bromine has recently been recognized as an essential element. I’m all for believing that bromine can be toxic in high dosages (as most things are), but I’m not sure why Brownstein is referring to this element as toxic from the get-go, and as if its detoxification from the body is a good thing (as doing so implies that bromine/bromide is problematic at any dose).

Secondly, Japanese seaweed – which is high in iodine – also contains ~10x more bromine than iodine. Brownstein has argued that one reason why Japanese populations are so robust / healthy is because of their seaweed (and thereby, iodine) intake. How can he hold this belief if he also believes that mega-dosing iodine helps to clear out “toxic” bromine? This seems a bit contradictory.

Thirdly, there’s also evidence that iodine supplementation does not clear out bromide/bromide, and that the effects of the 8-person study cited by Brownstein were likely the result of using Ion Electrode testing rather than more advanced testing methodologies. To quote from this author:

To investigate how much bromine is actually being spilled into urine following a loading dose of iodine, we sent matched urine samples containing high levels of iodine (exactly 50 mg of Iodoral dissolved in a urine sample with very low iodine levels) to a lab using the Ion Electrode method and to a second lab using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). We asked them to measure iodine and bromine. Both labs gave similar and accurate iodine levels, but only the lab using the Ion Electrode method came back with high bromine. ICP-MS is the gold standard
for testing elements like iodine and bromine, so its results trump those of an Ion Electrode method… Bottom line is that the Ion Electrode method was likely measuring iodine instead of bromine – it’s an artifact or false bromine signal caused by the very high levels of iodine in the urine. Our laboratory performs elemental analyses using an ICP-MS, and we can confirm that iodine at high dose is not pushing out bromine. However, if the same samples are tested for bromine by the Ion Electrode method the bromine levels would be falsely elevated.“

3. Brownstein claims that, “Iodine levels have fallen over 50% in the last 30 years in the United States”. His source for this claim is The National Health and Nutrition Survey. This is self-reported survey data; it’s a survey that asks for participants to recall their food choices. It’s not serum or urinary iodine readings. So, Brownstein’s claim misconstrues the data he’s using to support his statement. In fact, his claim is just outright wrong… because we can’t use self-reported food data as a surrogate for someone’s actual nutritional statuses.

On that note, Brownstein neglects to mention that 1/3rd of the participants in recent NHN surveys actually provided urine samples for iodine, and that this data was also published (source). The conclusions from the authors?

There is no overt sign of widespread iodine deficiency in the US, based on the observed mUIC from NHANES 2011–2014.

4. Brownstein’s article relies almost entirely on his clinical experience mega-dosing patients with iodine. It relies on very little peer-reviewed publications, and of the publications he does cite, he seems to have either cherrypicked those studies, misrepresented their findings in the context of the broader researcher, or made false claims about the actual data he uses to build his case (see points #1-#3).

5. Brownstein sells iodine supplements. I wouldn’t necessarily see this as a problem, but given all of the issues above, this has to be biasing his interpretation of the evidence.

I’m not saying that mega-dosing iodine is problematic for everyone. In some cases, it might be great! And I do think iodine supplementation makes sense for many people – especially those with iodine deficiency-driven hypothyroidism. And in those cases, there’s a chance that iodine supplementation may even help improve hair loss.

Having said that, I think that Dr. Brownstein is a far cry from an “iodine-literate doctor”. His unreliable testing methodologies, cherrypicked studies, paradoxical viewpoints, mischaracterizations of survey data, and near-complete absence of citations paint him more like an unreliable narrator than a medical professional. But I’m happy to hear your thoughts on the above. Again, I’m always open to revising my opinions.

All my best,
Rob

Most medical professionals are unfortunately under-educated on the topic of iodine, especially given its complexity. Judging from your article, it would seem that you may not have read materials written by iodine-literate doctors. I would suggest starting with Dr. Brownstein’s book: “Iodine: Why You Need It, Why You Can’t Live Without It”. Here is a preview: optimox/com/iodine-study-9