Iodine: A necessary nutrient, and not just for our thyroid

Published on: October 15, 2020

How I realized iodine is an important nutrient for our reproductive organs

Greta Thunberg isn't the only one to recognize a health condition as a blessing (or as she refers to it as a superpower). Here's how a diagnosis of hypothyroidism made me realize the importance of iodine in our diets.

In 2016, I started gaining weight.  Not a lot of weight, but definitely enough for me to notice.  My weight steadily increased over the next two years while my appetite kept plummeting in spite of absolutely no change in my exercise regimen or diet. 

I saw four different doctors during this time period, and their recommendations ranged from keeping a food journal to accepting the weight gain because I'd reached that magic age where my metabolism changed overnight (to which I asked "Like a light switch?" to which she replied "Yes." Needless to say, I haven't been back to see that doctor).

In 2018, I started having yet another symptom...a slight full feeling in the right side of my neck. So, I scheduled an appointment with yet another doctor hoping he might give me a different answer than the previous four. 

And, that's how I was diagnosed with autoimmune thyroiditis.  This doctor actually listened to me and was smart enough to test my thyroid antibodies. 

For those of you who don't know, it is possible to have normal thyroid hormone levels (TSH, T3, T4, free T3, and free T4), and STILL have an autoimmune thyroid condition. 

The body can make a number of different antibodies that can attack the thyroid.  In my case, my anti-thyroid peroxidase antibody (anti-TPO antibody) levels were high, but all of my thyroid hormone levels were normal.

Hypothyroidism & Dietary Iodine

Because all my thyroid hormone levels were (and still are) normal, Western medicine couldn't offer me much help.  I didn't let that stop me from trying to figure out how to feel better and get those anti-TPO levels down.

This may be a personal opinion of mine, but by and large Western medicine (or at least the doctors practicing it) hasn't yet caught up to Western science, so I headed to Google Scholar to figure out how to heal myself.

What I learned was enough to deem myself an amateur "expert" on immunology: check out Immunology 101: Balancing T helper cells and T regulatory cells if you're interested in reading more about what I learned regarding adaptogens and immune modulation.

Diet and dietary supplements presented over and over again as I researched how to make my immune system stop attacking my thyroid gland. 

I started supplementing daily with a highly bioavailable selenium and stopped taking all supplements containing iodine because so many articles contra-indicated iodine intake with Hashimoto's. 

Boy was that a mistake!

Within a month of eliminating supplemental iodine from my diet, I developed a painful breast cyst.  Back to Google Scholar where I found out that iodine is a necessary nutrient not just for thyroid health but also for breasts, ovaries, and prostate.

Iodine and Breast Health

A large body of scientific literature shows that iodine can reverse fibrocystic breast disease and also prevent and treat breast cancer. 

While some of these studies simply look at the increased incidence of breast cancer and the decreased intake of iodine and assume causality, there are plenty of studies out there looking at animal models, human breast cells in petri dishes (in vitro), and human studies to evaluate iodine's impact on breast health.

One study in a paper published late in 2016 shows compelling results that iodine inhibits growth of breast cancer cells and induces cell death of breast cancer cells1.  While this study was conducted in vitro (petri dish of particular types of breast cancer cells treated with iodine), at least three human trials show that fibrocystic breast tissue is reduced or eliminated, and researchers believe fibrocystic breast disease is a precursor to breast cancer2

Why exactly iodine is so beneficial for breast health is still being researched, but it seems to play a multi-functional role in maintaining healthy breasts by:

  1. Desensitizing estrogen receptors in the breasts
  2. Reducing estrogen production in overactive ovaries
  3. Increasing progesterone production
  4. Triggering cell cycle differentiation.  This is important because cancer cells typically display characteristics of undifferentiated cells.
  5. Decreasing peroxidation of lipids, which are oil soluble compounds like fatty acids and oil soluble hormones.  Basically, iodine acts as an anti-oxidant.
Wondering which hormones are oil soluble?  Estrogen, progesterone, testosterone, cortisol, and aldosterone are a few oil soluble hormones.


Iodine and Ovarian Health

Several studies show that the symptoms of Polycystic Ovarian Syndrome (PCOS) are relieved by supplementing with iodine, namely iodine helped restore normal menstruation3.  Now, this may be due to subclinical (undetectable by blood tests) or undiagnosed hypothyroidism3,4, but the ovaries have the highest concentration of iodine than any other organ in the body except for the thyroid3

Studies haven't yet figured out the role of iodine in ovaries, but it appears the ovaries can convert T4 (a thyroid hormone) to T3 (another thyroid hormone)5

For all women out there who are pregnant or want to become pregnant, iodine deficiency has also been tied to abnormal fetal development and mental development of babies, toddlers, and children7

Iodine and Testicular Health

It's a little harder to find whether the testicles have iodine receptors, but what is clear is that men who are treated with radioactive iodine for thyroid cancer tend to experience problems with sperm damage that is directly related to the dose of radioactive iodine received during the course of treatment8

This phenomenon indicates that there are thyroid receptors in the testicles or that thyroid hormones (T3 and T4), which incorporate iodine into their structures as shown in the image below, are necessary for normal testicular function, and when radioactive iodine is present in the body, testicular health is impacted.

Structures of the thyroid hormones T3 and T4.

Iodine Intake and Other Bodily Functions

One study I came across while researching this post used mice to evaluate effects of iodine intake on triglyceride and cholesterol levels.  This study found that iodine deficiency correlated with higher low density lipoproteins (LDL, better known as the bad cholesterol), higher triglyceride levels, and higher total cholesterol. 

A second group of mice in this study were fed a diet with excess iodine.  After 8 months, the females in this group had lower total cholesterol levels, and the males in this group had lower triglyceride levels than the iodine deficient group9.

How much iodine should you take?

The Food & Nutrition Board recommends 150 micrograms per day for adults.  Nearly double that is recommended for pregnant women and lactating women10

The population of Japan consumes nearly 100 times the RDA for iodine3 and has a low incidence of hypothyroidism and breast cancer.  Studies using 3 to 6 milligrams (20 to 40 times the RDA) of iodine effectively treated fibrocystic breast disease11.  It is unclear whether the iodine intake in that study was consumed daily or over a duration of days or weeks.

And, here's where I should point out, I'm not a doctor, so I'm not telling you what you should do.  Here's what is working for me:

I have increased my daily intake of iodine to about 675 micrograms per day, and I am not having any symptoms of Hashimoto's or cystic breast pain as long as I stick to my gluten free diet and maintain my selenium (L-Selenomethionine) intake of between 50-100 micrograms a day - be cautious with selenium because too much is not a good thing. 

Since I've been gluten free, I no longer have a constant full feeling in the right side of my neck due to swollen lymph nodes (see the Other Reference (Presentation of Lymph Nodes in Hashimoto's Thyroiditis) if you need some peer reviewed journal articles to get your doctor to pay attention to you on this symptom in particular).

I had to go on a low dose of levothyroxine (synthetic thyroid hormone) to get my appetite back, my weight under some semblance of control, and rid myself of pretibial myxedema (a skin condition associated with out of whack thyroid hormones though typically associated with Graves' disease rather than Hashimoto's... believe me, I tried EVERYTHING to resolve this myself). 

My TSH levels were in the normal range, but my symptoms weren't gone.  If you find yourself in this situation, it takes having a good doctor to get the treatment you need.  Good doctors are out there, so don't give up.

You'll notice the treatment that is working for me is a blend of Western medicine, dietary restrictions, and supplements. I'm not a doctor, but I know a combination of Western medicine, alternative healing modalities, diet, and supplements is the best blend to achieve a state of wellness in my own body.

If you found this article helpful, I'd love for you to sign up for Rain Organica's newsletter.  Yes, we focus on simple, portable skincare products you can use anywhere, but skincare doesn't stop at what we put on our skin.  We treat skincare holistically, because a healthy you radiates the healthiest skin possible. 

If you're looking for more posts like this, you may love these:



2 Fluoride Interactions with Iodine and Iodide:  Implications for Breast Health

3Orthoiodosupplementation: Iodine sufficiency of the whole human body

4Prevalence of autoimmune thyroiditis in patients with polycystic ovary syndrome

5Ovarian iodide uptake and triiodothyronine generation in follicular fluid: The enigma of the thyroid ovary interaction

6Iodine, Iodine metabolism and Iodine deficiency disorders revisited

7Importance of thyroid hormones for normal pregnancy

8Testicular Damage After Radioactive Iodine (I‐131) Therapy for Thyroid Cancer

9The Impact of Dietary Iodine Intake on Lipid Metabolism in Mice

10Fact Sheet for Health Professionals: Recommended Iodine Intake

11Iodine: Deficiency and Therapeutic Considerations

Other References (Iodine Specific)

Changes in Dietary Iodine Explains Increasing Incidence of Breast Cancer with Distant Involvement in Young Women

Optimum Levels of Iodine for Greatest Mental and Physical Health

Other References (Hashimoto's and Enlarged Lymph Nodes)

Hashimoto's Thyroiditis

The presentation of lymph nodes in Hashimoto’s thyroiditis on ultrasound

Shifting cervical lymphadenopathy in Hashimoto’s disease

Neck Lymph Nodes in Chronic Autoimmune Thyroiditis: The Sonographic Pattern


Brandy Searcy founder Rain Organica

About the Author

Brandy's a formulation scientist and self-proclaimed health geek who loves hiking, gardening, bird-watching, and body boarding. 

Her struggle with acne during her teens and 20s led to a holistic and healthy approach to skincare, embracing skin as an organ to be loved and cared for rather than a canvas to wage war on. 

Since 2008, she's been developing all-in-one products for a simple routine at home, & Rain Organica started when her backpacking friends asked for a portable skincare routine to keep their skin healthy & happy on and off the trails.

You can try Rain Organica for yourself with The Essentials Kit, a complete skincare routine in just 3 steps.

Brandy's LinkedIn Bio

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