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Iodine: The Forgotten Nutrient

by Marek Doyle(more info)

listed in nutrition, originally published in issue 182 - May 2011

Learning Objectives

  1. Understand the effects of iodine in the body;
  2. Become familiar with the historical use of iodine and why it is so often overlooked;
  3. To be able to recognize which clients are in need of more iodine.

What is Iodine and Why do we Need It?
Iodine is an essential element that is required by every single cell in the human body. It is found in nature in seaweed, especially kelp, and is known to have a wide range of beneficial effects in the human body. Iodine:

  • Is an anti-oxidant;
  • Is an anti-viral, anti-bacterial and anti-fungal;
  • Moderates the body's cortisol response during stress;
  • Improves sleep;
  • Provides control of oestrogen;
  • Supports thyroid function; 
  • Increases hormonal sensitivity at all brain/body tissues; 
  • Increases elimination of lead, mercury, cadmium, aluminium, fluoride and bromide;[1] 
  • Reduces histamine formation and lowers eosinophils count.[2] 

Good for Dieting, Good for Muscle Growth, Good for Detoxing Oestrogen
Athletes and bodybuilders are more likely than most to be short on iodine. A litre of sweat contains around 40mcg iodine, which means we could lose up to 150mcg per day.[3] Restoring lost stores of iodine will provide a major benefit to any athlete. Whilst the above effects are useful for everyone, athletes could benefit more than most from iodine's effect on oestrogen and hormonal sensitivity. The value of increasing sensitivity to testosterone is a no-brainer, but the attenuation of the body's release of cortisol during stressful times is another important function of iodine that can effect both health and physique.

Iodine levels have a major say in how the body processes oestrogen. Not only is their competition between iodine and oestrogen at many receptors around the body, iodine also encourages the body to maintain a healthier oestrogen balance by increasing oestriol whilst reducing oestrone and oestriadiol.[4] Iodine deficiency is the common factor behind oestrogen-dependent breast/ovarian cancer, fibrocystic breast disease and oestrogen dominance, but it could also be behind male bodybuilders holding onto more water than desired and females holding disproportionate levels of fat around the upper thighs and glutes.

Of course, there are many benefits of iodine beyond its support for athletic endeavours. Individuals are much more likely to stick to diets when they provide their body with sufficient iodine; this is likely due to the combined effects of increased leptin sensitivity which will moderate hunger sensations, together with the strong control that iodine has over fungal/yeast growths, a common factor in carbohydrate cravings.

What Effects can Athletes Expect from Iodine Supplementation?
Because of its widespread effects throughout the body, replenishment of iodine stores can have a number of different effects in athletes. Better mood and concentration are normal improvements, together with deeper sleep and more consistent adherence to the dietary directions I make. Whilst it is great for making fungal nails or athlete's foot disappear, introducing iodine often eliminates long-term complaints that individuals did not even realize were fungus-related. The elimination of heavy metals that it encourages can positively affect a wide variety of different body systems, the immune system in particular. As with other nutrients, we are all respond slightly differently to iodine deficiency, thus our experiences upon restoration are also slightly different.

More uniform responses occur in the case of IDDs. This disorders include: goitre, hypothyroidism, hyperthyroidism, fibrocystic breast disease, breast/ovarian cancer, oestrogen dominance and PCOS. There is also a uniform inverse correlation to the levels of iodine in the body and the incidence of cancers.

Are we all affected? Well, some individuals are going to be more susceptible to the iodine deficiency than others, but the increased rate of fungal infections, immune system imbalances, oestrogenic disorders, poor sleep and breast disease seen across Western society would appear to tell its own story; even without the appearance of measurable Iodine Deficiency Disorders (IDDs), one can stand to gain in terms of energy and mood levels. The incidence of one such IDD, fibrocystic breast disease, is often used as a gauge of iodine deficiency across a population. Autopsies show that 97% of women in our society now develop cysts in breast tissue, whereas this figure was just 4% in the era of widespread iodine use.[5, 6]

Why aren't we Getting Enough?
Without a shadow of a doubt, we are not getting nearly enough iodine. The recommendations for intake are woefully low, which seems due to a combination of ignorance and political interference. There are a number of current textbooks that shamelessly state that "the only known role of iodine in humans is to serve as an element essential to the synthesis of hormones secreted by the thyroid gland".[7] Not only is this inaccurate - the thyroid represents only 3% of the body's stores of iodine[1] - but it is also what is taught in the medical mainstream, which serves to produce a generation of doctors who think that iodine intake is sufficient if there is no goitre present. There is also a creeping culture of iodophobia which pervades through our medical profession, despite the widely-documented use of high-dose iodine (more than 1g/day) for more than a century.[1]

This iodiophobia has its roots in the much-criticised 1948 experiment by Wolff and Chaikoff,[8] where it was concluded that excessive iodine intake suppressed thyroid hormone output. Although this was a one-off experiment conducted with rats and that its findings have not been replicated in similar research since,[9] this was considered enough for the powers-that-be to abandon iodine, then the standard treatment for both hypo- and hyper-thyroidism, and use synthetic thyroxin in its place. Thyroxin and other thyroid preparations remain amongst the biggest-selling drugs of our time.

It would seem that political inference persists to this day in making recommendations for iodine intake; having studied the EU's 2002 report on the Tolerable Upper Intake of iodine, I noticed that although the authors were clearly keen to emphasize the side effects of iodine, there was no identification of these side effects or any documentation that any populations had ever suffered problem them. I also noticed that, although the report was happy to discuss population studies from as far and wide as Zimbabwe and the Democratic Republic of Congo, there was an inexplicable omission of any reference to Iceland and, in 25 pages of analysis, Japan was mentioned in just one sentence. To say that this is a serious flaw is an understatement, as both Japan and Iceland are both universally recognized for both their extremely low rates of iodine deficiency disorders like thyroid issues and breast/ovarian cancer.[10,11,12]

A single experiment in 1948[8] and the desire of drug companies to use thyroid drugs ahead of iodine has seen the discussion of iodine pushed very much to the sidelines. The recent EFSA report on iodine backed the EU's 2002 report and made no criticisms of its selective discussion. This selective discussion of iodine use is not the only obstacle for a deficient population; in 2007, the federal government in the USA made Lugol's solution - the popular form of iodine - a controlled substance.[13] The basis given was that this solution could be used for the illicit manufacturing of methamphetamine. Naturally, no statement was provided for their expectations this move may have on the health of their already-iodine-deficient population.

What Should we do about It?
When it comes to deciding the optimum intake level, there are a number of considerations, not least an individual's constitution. As with all nutrients, the most basic question is: what amount is enough to avoid all the Iodine Deficiency Disorders but also provides margin for any toxicity or side effects, the most common of which is iodism. Two drops of Lugols solution each day was used regularly before WWII to ward off any incidence of thyroid dysfunction and did so very admirably.[1] This dosage provided around 12.5mg of iodine each day but, as your grandmother may tell you, did not cause iodism despite being well above today's recommended intake. The average mainland Japanese citizen consumes 13.8mg of iodine each day, which is higher than most populations, and enjoys minimal iodine deficiency disorders, such as thyroid enlargement, fibrocystic breast disease or cancer. Iodism and iodine toxicity is virtually nil for mainland Japanese. Dr Abraham compared the incidence of iodism reported across long-term trials[14,15] and found that the rate of iodism was increased at higher daily doses of iodine - it simply did not occur at a daily amount of 1.4-2mg, occurred at a rate of 0.1% with 3-6mg daily, occurred at a rate of 0.5% with 9mg, and at 3% when using 30-60mg each day. There is a fair likelihood that related mineral deficiencies may have increased the appearance rate of iodism, but there is no data available in this area. What can be taken from this summary of the available research is that 13.8mg appears to very adequate to meet our needs, but this level there is still minimal incidence of any iodism.

I take two drops of Lugol's solution each day, which provides 12.5mg, and recommend the same dosage to my clients. This provides the body with sufficient iodine not just for the thyroid, but for every other cell in the human body. The body can only perform the actions it is designed to perform in the presence of the nutrients we have evolved to consume; we have clearly evolved to take in considerably more iodine than we are currently consuming. Iodine is part of the jigsaw puzzle of optimal health but, as proved by the alarming increased in associated deficiency disorders, it is one we really miss when it is absent. Just because the medical world has forgotten the importance of iodine, doesn't mean you have to!

1. Abraham, GE. The safe and effective implementation of orthoiodosupplementation in medical practice. The Original Internist, 11(1):17-36. 2004.
2. Abraham GE, Flechas JD, Hakala JC. Orthoiodosupplementation: Iodine Sufficiency of the Whole Human Body. The Original Internist, 9: 30-41. 2002.
3. Consolazio CF et al. Comparison of nitrogen, calcium and iodine excretion in arm and total body sweat. American Journal of Clinical Nutrition, 18:443. 1966.
4. Wright JV. Bio-identical steroid hormone replacement: selected observations from 23 years of clinical and laboratory practise. Annual of New York Academy of Sciences, 1057:506-24. 2005.
5. Kramer,WM., Rubin BF. Mammary duct proliferation in the elderly: a histopathologic study. Cancer, 31:130-137. 1973.
6. Sem, BC. Pathologico-anatomical and clinical investigations of fibroadenomatosis cystica mammae and its relations to other pathological conditions in mammae especially cancer, Acta Chir Scand, 10:1-48. 1928.
7. Fink H. Practical Applications in Sports Nutrition. Jones and Bartlett. 2005.
8. Wolff J and Chaikoff IL. Plasma inorganic iodide as a homeostatic regulator of thyroid function. Journal of Biological Chemistry, 174:555-564. 1948.
9. Abraham, GE. The Wolff-Chaikoff effect: Crying Wolf? Original Internist, 12(3): 112-118. 2005.
10. Cann S., Netten J., Netten C. Hypothesis: Iodine, selenium and the development of breast cancer, Cancer Causes and Control 11:121-127. 2000.
11. Stadel B. Dietary Iodine and Risk of Breast, Endometrial, and Ovarian Cancer, The Lancet, 1:890-891. 1976.
12. Finley JW and Bogardus GM Breast cancer and thyroid disease. Quarterly Review in Obstetics and Gynocology, 17:139-147. 1960.
13. USDEA. "Final Rule: Changes in the Regulation of Iodine Crystals and Chemical Mixtures Containing Over 2.2 Percent Iodine," Federal Register, 72: 126. 2007.
14. Marine D. Prevention and Treatment of Simple Goiter, Atl Medical Journal, 26:437-442. 1923.
15. Ghent, W., Eskin, B., Low, D., Hill, L. Iodine Replacement in Fibrocystic Disease of the Breast, Canadian Journal of Surgery, 36:453-460. 1993.


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About Marek Doyle

Marek Doyle Dip Advanced Nutrition for Optimal Health DipAET CertHE Nutr Med  is a Nutritional Consultant, Allergist and a Personal Trainer. With locations in Kensington, Chelsea and Basingstoke, he has been recognized as one of the top trainers in the country, and counts world champion athletes, cover models and TV personalities amongst his clientele. Marek has set up The Academy to increase knowledge and training regarding optimizing metabolic function. Topics covered include Adrenal / Hormonal Balance, Sleep / Neurotransmitters, Nutrition and Diet Fat Loss, Body Composition, and Methylation / Epigenetics / Metabolic pathways.  Marek may be contacted via

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