"Healthy" people are the most iodine deficient

Ironically, the healthiest people are the most likely to be deficient in iodine.


Healthy people tend to:

--Avoid iodized salt because of public health advice to limit sodium
--Use sea salt to obtain minerals like magnesium--but sea salt contains little iodine
--Limit meat--Carnivores obtain more iodine than vegetarians or vegans. In one study, up to 80% of vegans were iodine-deficient (Krajcovicova-Kudlackova M et al 2003).
--Exercise--Substantial amounts of iodine are lost through sweating. In a study of high school soccer players, 38.5% were severely iodine deficient, compared to 2% of sedentary students (Mao IF et al 2001).

That is indeed what I am seeing in my office, as well: The healthiest, most attentive to healthy eating, and most physically active are the ones showing up with small goiters (enlarged thyroid glands) and increased TSH and low free T4 levels.

Why am I checking thyroid and talking about iodine? Because even the smallest degree of thyroid dysfunction can double, triple, or quadruple your risk for cardiovascular events. See the posts Is normal TSH too high? and Thyroid perspective update.

Comments (27) -

  • thequickbrownfox

    6/6/2009 9:07:44 AM |

    Interesting. Your posts are very informative but could I suggest that you consolidate them all into one document per topic (e.g. iodine). I realise it might be too early to do this in some cases if you are on a journey of discovery yourself but I think it would be very valuable to have all of your thoughts on a subject cohesively presented in one chunk. As it stands, you have to be following this blog to get the full picture of what you're talking about, unless you are willing to trawl through previous posts.

    Perhaps you could do it in the form of an editable wiki-like page which shows past changes, or just a post that keeps getting edited with a "last updated" note. Or failing all of that you could just tag all your iodine-related posts with "iodine".

    I think you have something valuable to say but if you want it to be accessible to wandering internet users you should think about the presentation more.

    Thanks and keep up the good work!

  • steve K

    6/6/2009 12:42:03 PM |

    you seem to be basing your views on thyroid and heart disease on the HUNT study, and the more recent one you cite, however, the results seem to indicate low thyroid and cardiac events more associated with woman then men.  There did not appear to be a relationship with low thyroid and coronary events in men.  If so, why the across the board reoommendation for iodine for both me and women in light of data not crystal clear for men?

  • TedHutchinson

    6/6/2009 1:21:26 PM |

    I find using the search facility brings up all the blogs on Iodine
    However perhaps you are right as there are now sufficient blogs about IODINE for them to be given their own label.

  • Keenan

    6/6/2009 4:00:35 PM |

    Do healthy people limit meat? Or do you mean people that are attentive to their health, even if they're following not-so-great advice?

  • Allison

    6/6/2009 4:12:12 PM |

    I disagree with thequickbrownfox.  Repetition is good.  After the first two iodine posts I made a mental note to get some iodine or kelp and promptly forgot.  It was after the third iodine post that I finally acted: I bought iodine and started taking it.  

    I also appreciate that the posts are brief; I have bookmarked dozens of long posts in Dr. Eades' blog that are always too long to read right now.  

    Don't change anything.  I love this blog the way it is.  Thank you for taking the time to pass along your knowledge. Smile

  • kris

    6/6/2009 6:14:20 PM |

    i think the search option on the upper left corner works just fine if some one searches it for example. iodine, thyroid, vitamin d3 etc.

  • Nameless

    6/6/2009 11:02:16 PM |

    Although I think Dr. Davis is right about many things, I'm not so sure he's so right about iodine. Why not recommend iodine testing first? Supplementing with no idea if the person is deficient or not doesn't make sense to me.

    If thyroid function is low, what if it's due to Hashimoto's and increased iodine worsens the condition?

    I would have a concern about the person who glances over these blogs, feels their suspected sluggish thyroid needs some iodine help, then worsens their health due to Hashi's.

  • Kismet

    6/7/2009 1:32:00 PM |

    steve K, you're right. The data in men is not convincing re. iodine or thyroid; difficult to say why exactly. However, I've read some convincing mechanistical evidence suggesting that low T3/T4 levels likely promote CVD. It's quite a believable hypothesis.

    However, I'm somewhat worried about 'messing' with such an important hormone, even though we don't understand all the details and don't have a clue what the 'default setting' of our body is and whether the default values would be any good re. long term health (not just CVD).

    IIRC Hypothyroid snell dwarf mice exhibit an increased life span and no clear benefits of T3/T4 supplementation have been demonstrated in the elderly/very old.

    Hi Nameless! Even though Dr. Davis has presented some interesting evidence showing that healthy people may be more prone to deficiency, I second what you say:
    Get a doctor's opinion before treating yourself, check thyroid levels and also try to get baseline iodine levels (urinary excretion).

    Even though iodine (and vitamin D) are free of side-effects in most people, there are diseases which can precule supplemenation (w/o medical supervision at least).

  • Anonymous

    6/7/2009 9:38:14 PM |

    Iodine does not worsen Hashi's. It's used to cure Hashi's.

  • kris

    6/8/2009 2:23:25 AM |

    the study:
    "IIRC Hypothyroid snell dwarf mice exhibit an increased life span and no clear benefits of T3/T4 supplementation have been demonstrated in the elderly/very old".
    However, few things these studies are not able to demonstrate that how do these mice feel and they don't have to live and perform in a society like us humans?
    people with hypothyroid may look normal, are able to complete day to day tasks like a normal person(specially high will power individuals, athletes etc.). But yet these individuals feel terrible from inside.  The symptoms may includes the followings:
    Over reacting,
    Over thinking,
    Low stamina even though 7 days week at the gym and eating healthy,
    See themselves as victims for no apparent reason,
    Not successful in relationships.
    Not being able to hold job.
    Split personality in seconds.

    I believe that the only doctors, who are hypo or hyper themselves and have treated their thyroid misery successfully, can then understand fully as to what this disease is all about and what was poor patient crying about?  This is not even close to one study fits all kind of disease.
    The notion "get doctor’s opinion" has gotten low marks on my list after suffering with hypo all of my life and going through bunch of most dumb doctors that I have seen and I can bet that most of those doctors themselves are suffering from either low iodine or thyroid.
    When someone gets medical college's degree and license, doesn't necessarily means that he or she is "God". My faith has completely shaken in most of these doctors who try to fit every human being in to the "normal" test numbers.
    The internet is the best thing happened to the society. Where no one needs any "degree" to give their opinion. Where no medical college can suspend any license to punish people, who don't fall in to the drug company driven education trap.  
    Even for a moment, if we believe in the notion of “get doctor’s opinion”. Then Doctor Davis is a doctor and he is giving his opinion. What is wrong with it?
    me and my family has suffered for all of our lives with simple stubbornness of the stupid doctors and i don't wish any body else to go through the same. therefore the best remedy is to educate your self. your body is the most important tool that good has given. spend some time educating your self.  
    As  Dr. Abraham, G.E   is explaining that,
    “The worst form of domestic bioterrorism is the dissemination of iodophobic misinformation in order to discourage the use of adequate amount of iodine for whole body sufficiency (orthoiodosupplementation).2-4 Today, the public relies heavily on the Internet for health information. Rarely do they search for the original publications. Whoever supplies health information on the Internet controls the health of the Internet user. Control of health information on the Internet by iodophobic bioterrorists is a real threat to a population who depends on this source of information to make health-related decisions. Such a population is vulnerable and most likely will end up adopting iodophobic decisions to their detriment. Once caught in the iodophobic Net, it becomes a vicious cycle, difficult to exit.
    Iodophobic bioterrorism can be prevented through education of health care professionals and the public at large. Remember that the easiest and most effective way to destroy a nation is the removal of iodine from the food supply. Iodophobic bioterrorism is a real threat to our nation, and the enemies within our gates masquerade as guardians of our thyroid gland”.
    Here is link to the full article.


  • Nameless

    6/8/2009 4:01:29 AM |

    I've read conflicting info regarding iodine and Hashimoto's. There is some data suggesting iodine can make matters worse.

    And iodine doesn't 'cure' Hashimoto's (or at least I haven't found any evidence it cures it). It may improve thyroid function if hypo, but Hashimoto's is when thyroid antibodies attack the thyroid gland. Selenium + thyroid hormones can lower these antibodies, but I haven't read any data as to iodine having the same effect.


  • Anonymous

    6/8/2009 4:46:37 AM |

    How much of this is localized?  Isn't Dr. Davis located in Wisconsin, which known to have low iodine in the soil?

  • Dr. William Davis

    6/8/2009 12:17:13 PM |

    Thanks for the wonderful description, Kris.

  • Dr. William Davis

    6/8/2009 12:19:41 PM |

    Iodine does indeed make Hashimoto's worse if taken during a flare-up. Iodine will make any form of hyperthyroidism worse, for that matter.

    However, it does not mean that iodine is not important for health for the other 99%+ of people, those not in the midst of a hyperthyroid flare.

    Iodine need is life-long. That's why, when people are deprived for years, iodine provided to an iodine-deficient person can encounter a thyroid unaccustomed to sufficient iodine. This can also provoke transient hyperthyroidism. I've seen this happen twice in the last several hundred people.

  • TedHutchinson

    6/8/2009 1:46:39 PM |

    There is quite a long lecture from Dr. Brownstein at this link.
    Iodine_->The_Most Misunderstood_Nutrient Iodine: Why You Need It, Why You Can't Live Without It.
    Dr. Brownstein feels iodine is the most misunderstood nutrient.
    He feels it is impossible to achieve your optimal health when there is iodine deficiency present.

  • StephenB

    6/8/2009 5:13:16 PM |

    Dr. Davis, any thoughts about why hypothyroidism and low ferritin levels seem to be associated? Does iodine deficiency adversely impact iron storage?

  • Nameless

    6/8/2009 5:57:56 PM |

    But what about Hashi people who become even more hypo with iodine treatment?  I know this sounds contradictory to what you are saying, but it's been reported on pubmed as occurring (autoimmune reaction causing more thyroid destruction perhaps?).

    Most of the articles I've read, in fact, say not to supplement iodine above RDA if you have Hashi's.

    For Doctor Davis' patients, this may be fine, since they are under a doctor's care. But I expect a decent percentage of people reading this blog who decide to take iodine won't be taking it through a doctor,  restrict only to RDA levels, get full thyroid workups or even iodine testing. I'm just saying some caution should be considered too... hence why to get tested before supplementing.

  • kris

    6/8/2009 7:07:35 PM |

    "Iodine does indeed make Hashimoto's worse if taken during a flare-up".
    Dr. Davis, while we are at this subject, here is more about hashi and iodine.


  • kris

    6/8/2009 11:04:16 PM |

    back in 2007 i read this. it came from another blog by Dr. Joe(don't know the last name)and it helps adding another dimension to this puzzle.
    "Graves' Disease Caused by a Tummy Ache?
    If you are like most people (and even most doctors), you may have a hard time wrapping your mind around the fact that a problem in your gut can cause a problem in your thyroid (which is way up in your neck). There is strong evidence that proves that this just might be the underlying issue in many cases of Graves' disease.
    Graves thyroiditis, also known as Graves' disease, is an autoimmune disorder that attacks the thyroid gland. While there can be acute attacks of thyroiditis, Graves' disease is usually a more slow acting autoimmune disorder.
    There is evidence that a specific strand of pathogen (though there can be many different kinds not as well documented) called Yersinia enterocolitica that has been shown to cause Graves thyroiditis.
    A common medical treatment for Graves thyroiditis is radiation or surgical removal of the thyroid gland. The thought is that if you remove the overactive thyroid gland, then you remove the problem. This line of thinking ignores the fact that there is still the underlying problem of the Yersinia enterocolitica.
    If the treatment was aimed in addressing the pathogen Yersinia enterocolitica instead of the thyroid, you may have been able to forgo the ablating of the thyroid gland.
    So how did Yersinia enterocolitica even get into the bloodstream to cause Graves' disease?
    Most likely in cases of dysbiosis (or overgrowth of unhealthy bugs within your gut lining), there is an overgrowth of Yersinia enterocolitica within the gut. When this pathogen is allowed to flourish in the gut lining, changes to the gut lining may enable Yersinia enterocolitica to pass through when it should not.

    Once Yersinia enterocolitica is in the bloodstream, your immune system recognizes it, tags it is a foreign invader, and then attacks it.
    It is believed that the protein makeup of Yersinia enterocolitica is similar to that of the protein structures on the thyroid. What happens is your immune system gets "tag happy" and tags your thyroid gland as well. Now your body cannot decipher a difference between Yersinia enterocolitica and your thyroid gland. You now have what is known as an autoimmune disease".

    if we read here:
    about infective agents and iodine, it may shed some light on this mystery.

  • Anonymous

    6/9/2009 4:45:58 PM |

    You might want to change the title of the post from "healthy" to "health-conscious." People who limit salt, fat, and meat, and who knock themselves out with exercise are not healthy, as your examination of them attests. They care about their health, but because they have assimilated all the current but erroneous commonplaces about how to be healthy, ironically they are unhealthy.

  • mike V

    6/10/2009 3:10:08 PM |

    Hi Doc:

    The fundamental importance of thyroid and vitamin D status to heart, vascular, and general health have interested me for many years, and your willingness to provide some informal feedback from your patient base is unique.

    I have another supplement that I have studied, and used moderately for going on  20 years, and which I believe has significance in the broader context. (personally I am in excellent health in my 74th year).
    The supplement is melatonin, which has been primarily asociated with sleep, but which I believe is much more fundamental. (relevant to TYP?)
    I imagine that a high percentage of both your patients and blog followers are in their mid to later years, and may have used or considered it.

    The following LEF article sums it up pretty well. Would you please consider, and give us your assessment.




  • homertobias

    6/10/2009 3:10:33 PM |

    Dr Davis

    Check out Kamstrup's new article on LP(a) in the new JAMA.  Interesting stuff.  Two new THYROMIMETIC drugs in the pipeline to lower LP(a)?  I wonder just what is the relationship between thyroid function and LP(a) levels.

  • mike V

    6/10/2009 3:34:09 PM |

    I missed the fact that melatonin had previously been a topic in May.
    Mike V

  • Someone

    10/1/2009 7:05:16 PM |

    I started to take some custom lugols ( 7 % , 99.9 pure , 40% grain alcohol , 1 mg free iodine with around 3 mg KI) diluted in distilled water in small quantities of 10mg 2 months ago. I take in morning with empty stomach; I eat lot of Mg in fruits etc. I also eat yogurt a lot all my life.

    First I found that my lungs were more effective and my heart was very calm even when doing exercises. (Like the right ventricular was more effective with iodine supplement)

    after around 150mg ingested, after one month I started by having a slight pinching sensation on my heart just couple millimeters far from the sternum bone, on the left.

    After taking some more up to 350 mg cumulative dose for 2 months I had many upsets especially in the evenings. It happened 7 times, but last night I panicked because my heart seems to stop working in the right ventricular for around 30 seconds, I was in sweat, shaking white and in shock. But no heart pain or chest pain at all, just a very bad discomfort, a feeling of something disturbed or that the heart pulse on the right side was very weak. The void in my chest lasted all morning, Aspirin didn’t help at all. I spent most of the day in bed because it seems to help my heart. Any effort brings back the symptoms.

    Very important is that these heart problems happen only when I take breaks from iodine; it seems to happen around 4 - 6 days after i stop taking iodine.

    I am taking an appointment with doc today.

    I really don’t feel with fever, or anything. Just this heart problem...

    I also experienced a metallic taste after 1.5 month and this is when I started to take 4 - 6 days breaks of iodine intake.

    Probably that if I am to resume iodine intake my heart will go back to normal but I won’t take it before I see a doctor.

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