Iodine (part 3): The Bundaberg experience
After all of that iodine talk, it’s probably time to come back to the real world, don't you agree? If iodine is as important as I have tried to paint in the previous two posts, but no one is deficient in it, then why bother? I think this is the narrative that is going around in Australia: We are a developed country, iodine deficiency does not exist in Australia, and testing therefore is a waste of money. Well, this may be a confirmation bias.
First, a clinician has to understand physiology in order to be able to begin to suspect a deficiency as part of the cause of their patient’s ailment. Next, they have to be of clear mind, free of influence that may encourage them to downplay the evidence that contradicts their belief. Then they need to run some tests and be open to their outcome. After all of that, the best way to consolidate their learning is by running an audit on that testing in order to see clearly whether there is a bigger picture of the deficiency or there isn’t one. Well, this is exactly what I have done and am about to present to you.
When I examined every single patient that I had sent for iodine testing between March and July of 2025—a period of 5 full months—the count came back as 52. That is an average of 10 patients a month being tested for iodine. 33 of them were deficient; that is a whopping 63.5% of the group, or if you want to round it up, you may say about two-thirds. Now that is in no way a small proportion, and the group size of 52 is not an insignificant number, considering peer-reviewed studies published in esteemed journals often have group sizes smaller than that. I did not make up the cut-off levels of adequacy and deficiency either; they were taken straight off WHO (World Health Organization). Do bear in mind, though, the WHO oversees the health of the different nations we have around the globe, and when it sets a bar of deficiency, the data used is primarily from the ‘developing’ countries. Let me just clarify that in statistics, when a deficiency/adequacy bar is set, it is decided based on the number where 50% of the population falls below and conversely the other 50% are above it. If you are in Australia and you fall below the minimum that was set by WHO, the context makes it worse. It means you are not even comparing yourself with fellow Australians; rather, you are deficient in comparison to our fellow extended family members who live with significantly less amenities and infrastructure.
The WHO cut-off of 100 mcg/L for deficiency/adequacy was decided nearly 30 years ago, and when ‘developed’ nations like the US, the UK, Germany, Finland, and Norway surveyed their iodine intake in the past decade or so, they have all reported deficiency as common in their study cohorts. I am not aware of any Australian study, but personally, I don’t think we should be complacent about this.
Back to the audit. When I did the breakdown of which indications for testing scored the highest rates of deficiency, neurological symptoms came up top with 77%. If this data is representative, it means that if you go to your doctor with, say, pins and needles in the skin, unexplained dizziness, movement disorders, memory issues, or even brain fog, your chances of having low iodine is high. After neurology, tiredness comes in next with 75% of subjects being tested for iodine based on their symptoms of fatigue coming back as deficient. One can argue that tiredness is a neurological symptom, which compounds the impact of the data. Anyone wonder why I wrote the blog on iodine starting with its effects on the brain first?
The thyroid, if you are asking, came back at just below the half mark, at 47.6%. Still quite significant, but it is a dwarf when placed beside neurology/tiredness. Both camps are the same size, i.e., 21 patients in each. Now you are ready for the next truth bomb: in most people, our thyroid gland draws less than 10% of the body's circulating iodine when the level is adequate, but this goes up to 80% when we are deficient. The thyroid is holding its fort at the expense of the other organs that benefit from an iodine-rich environment. By simple math, this means that most iodine-deficient state presentations will be extra-thyroidal—probably neurology if you have read the previous blog. Well, this audit demonstrates exactly that.
I did also send 9 patients for iodine testing just for ‘completeness’ when they did not have neurology, fatigue, or thyroid symptoms, and 6 of them came back deficient. The last patient, who had a previous deficiency identified by another practitioner (hats off to them, probably way ahead of me and their time), still came back as deficient despite previous supplementation. That is all of the 52 patients who got tested. Before you think that the deficient subjects all had iodine levels of 99 mcg/L when the cut-off is 100 mcg/L, the data demonstrates that their median number is 64 mcg/L, with over a third of them falling below 50 mcg/L, which is quite shocking in my opinion. The lowest of them all had a level of 22 mcg/L.
My point is, I am not convinced that iodine deficiency is rare. If we have an Australian specific Median Urine Iodine Concentration (MUIC) rather than the global one we are using, the data is bound to get worse. I think we have an endemic of not understanding this element, not understanding how the body works and how the two interact, which is further compounded by our complacency.