G9. Iodine & Thyroid

Iodine is an essential mineral for the entire body and all of the endocrine glands, however it is so essential for the thyroid that the gland can preferentially take up iodine - so if there are low thyroid symptoms there may be low iodine too, (G9.1) or excess halides, (G9.2), excess nitrates, commonly used as preservatives in processed meats, (G9.6), or excess thiocyanate from cigarette smoke, first or secondhand, or cruciferous vegetables, which would be unlikely to be consumed in excess unless juicing large amounts of cruciferous vegetables such as kale, broccoli, cabbage, and cauliflower. (G9.7, G9.8)

     Iodine is a mineral that is essential for metabolism due to its role in the thyroid gland and thyroid hormone, and  it plays a role in the immune system. It may help protect against cancer and autism and other neurological risks in addition to protecting against congenital hypothyroidism in the newborn. Mothers need iodine for their entire body, not just a synthetic hormone replacement with no additional iodine being provided than might be found in a one-a-day supplement. The need for iodine is increased throughout pregnancy and during lactation and might worsen an underlying moderately low level of iodine into a level that causes hypothyroidism. The thyroid can preferentially use iodine when it is in limited supply because it is needed for thyroid hormone, however the mammary glands and all endocrine glands also need iodine. Thyroid hormone is needed throughout the body for energy production. Hypothyroidism can cause extreme tiredness, poor hair growth, feeling cold easily, and depression or apathy, and constipation.

     It is important to have selenium along with iodine rich supplements or foods as the enzyme required to break down excess amounts of thyroid hormone needs selenium in order to function properly. Two Brazil nuts per day or 200 mcg is the recommended amount of selenium to consume per day. Selenium can build up to toxic amounts if over eaten on a very regular basis. 

     Iodine toxicity is also possible, symptoms might include a rapid heart rate, feeling restless, an odd metallic taste in the mouth might occur that could also be due to the body excreting halides: bromide, chloride, and fluoride. Iodine toxicity would only be likely to occur with long term use of high dose supplements or extensive use of topical iodine sanitizing cleansers. Other symptoms might include feeling like there is something stuck in the throat, feeling a need to cough something out; a nasal watery drip may occur that is thin and more like an occasional tear rather than normal mucous and blowing the nose doesn't help because it isn't "clogged" it is just dripping occasionally, weeping almost. I'm familiar because I read about the symptoms in animal research and many years later happened to notice that I likely had continued a high dose iodine supplement too long, and'or I wasn't taking the recommended selenium at the time. 

     The long term benefit though has been an absence of fibrocystic breast pain which had been an uncomfortable problem for several years before I started the iodine supplement protocol by Dr. Brownstein. He has a website with information available online and more detail is included in several books. See Iodine: Why You Need It, for more information about use of a high dose iodine supplement for a few weeks to help clear the body of any stored bromide, chloride and fluoride.  (G9.3)
    The iodine content in food can vary a lot because iodized salt may or may not be used in processed foods and it is not required to be listed as a nutrient on the nutrient portion of a US Nutrient Food Label so the food content wouldn't be tested consistently either. Look among the ingredients for iodized salt or iodized sea salt. If the word salt or sea salt is listed then the food may not have much iodine naturally. Foods grown near the ocean such as coconut tend to be good sources because soil near the ocean has a higher iodine content than soil farther inland, away from ocean air. Ocean water is rich in iodine and some is carried inland from the sea air. Seafood and seaweed is a good source but the amount in seaweed can vary significantly and may occasionally be excessive. Kelp and kombu are two types of seaweed that have been found to have variable amounts of iodine while nori and wakame have been found to have more consistent amounts. Some plants like rhubarb are good sources of iodine because they preferentially absorb it from the soil. 

• Clinical resources regarding iodine: (G9.5).
• Continuing Education for dietitians:Unexpected Trends in Iodine Consumption — Interventions to Improve the Health of Women and Their Offspring  (G9.9)

Congenital hypothyroidism is a "birth defect" that is frequently treated with synthetic thyroid hormone instead of or without also providing iodine or iodide supplements. A patient forum left me feeling heart broken as several women were sharing their stories and questions regarding why congenital hypothyroidism seemed to "run" in their family?  - all three children of one women had been born with the condition, and two of three children for the mother who posted the original question - and none of the mothers or respondents seemed to be aware of the role of iodine. (G9.4)  

     Excess halides, bromide, chloride, and fluoride are also involved. The body needs extra iodine above the recommended daily goal if there is an excessive amount of halides present in the diet or in the stored body pool of toxins and nutrients.

     Prenatal care is important to think about once the infant is conceived but it can be even better to think about before trying to conceive. An evaluation for iodine level and thyroid antibodies can be a good idea for anyone but may also be helpful for a future infant's brain development. 

    Considering adequate iodine status before conceiving an infant may also help protect against autism. Mothers with hypothyroidism, even if taking the synthetic hormone replacement therapy, are more at risk for having an infant who develops autism as a child. 

     Illness is a limiting factor affecting too many people in the U.S. and elsewhere. The rate of autism in children has reached almost 2% of U.S. children and it is a condition that was not present in the medical history of psychiatric care prior to around 1930.  (Denial, Blaxill) Malnutrition of several nutrients in addition to iodine seem to be involved based on my reading (post) so the presence of the condition after 1930 may have to do with the Great Depression's impact on nutrition. 

Taking a prenatal vitamin or supplement of iodine with 150 micrograms of iodine prior to trying to conceive may be safest for the expected infant and may help with fertility. Iodine seems to be involved with implantation of the fertilized egg and is helping the infant development from day one of conception. 

The current nutrient guideline for iodine is based on a goal to prevent goiter which is a physical symptom of very severe iodine deficiency. Patients who are treated with a short term loading dose of extra iodine, a dose that would be too much if continued long term, report on average a significant reduction in symptoms including pain from Fibrocystic Breast Disease, migraines and fibromyalgia. http://www.jpands.org/vol11no4/millerd.pdf 

     Fibrocystic Breast Disease - painful breasts that may cycle with the monthly hormonal changes, used to be very uncommon for U.S. women and is now very common:

• "The incidence of fibrocystic breast disease in American women
  was 3 percent in the 1920s. Today, 90 percent of women have this
  disorder..." http://www.jpands.org/vol11no4/millerd.pdf

I am familiar with the condition, it hurt, taking a high dose iodine supplement did help relieve me of the cyclic breast pain and coincidentally also may have helped resolve a severe migraine problem that I had and undiagnosed fibromyalgia type pain - the insurance requirements for a diagnosis of fibromyalgia are very specific and my set of muscle knots didn't match the criteria at the time I was having pain. A gluten free diet seemed to help me feel better so I just followed that on my own initiative. I have since learned that chemically the gluten molecule is quite similar to the thyroid hormone and for some people an autoimmune reaction may be causing the body to become over-sensitized to both gluten and the thyroid hormone. Strictly avoiding the dietary allergen (gluten in this example) can help the body to become less over-reactive to the body's natural chemicals (thyroid hormone in this example). Molecular mimicry is the term used to describe this phenomenon if interested in reading more about it.

     A randomized clinical trial with patients reporting breast pain also termed Benign Breast Disease or cyclic mastalglia or Fibrocystic Breast Disease found that pain was reduced for patients treated with double the current RDA of iodine or greater but that relief was not provided for the group who received a dose equal to the current U.S. nutrient guideline. https://www.ncbi.nlm.nih.gov/pubmed/15239792

     Benign Breast Disease or Fibrocystic Breast Disease has not generally been found to be directly a risk for later breast cancer however for some patients (~ 5%-20%) it may be an early indicator of later risk.  Abstract available, full text paywall, so I'm not sure of the details regarding the results: https://www.ncbi.nlm.nih.gov/pubmed/25970956

     An overview of a variety of research on the topic of breast health and iodine and halide toxicity, bromine, perchlorates, and fluoride, is available here: https://kathleenbarnes.com/iodine-and-fibrocystic-breasts-and-breast-cancer/

     Excess perchlorate, especially in combination with low iodine, may increase risk to fetal brain development. https://scienmag.com/mothers-exposed-to-common-toxin-have-lower-levels-of-hormone-crucial-for-brain-development/