Iodine for Optimal Health

By Dr. Frank Aieta, N.D.

When many people hear the word iodine they immediately think of iodized table salt but few understand the relationship between this essential mineral and health. Iodine is the element necessary for the production of thyroid hormones, which have many important responsibilities throughout the body. I like to describe the thyroid as our body’s gas pedal. The thyroid produces hormones that tell our cells how quickly to convert the calories we eat into “fuel” or energy. In other words, the thyroid essentially controls our metabolism. If our thyroid does not receive adequate amounts of iodine, the thyroid glad can swell, known as goiter.

How Much Iodine Do I Need?

In this country, the recommended daily allowance (RDA) for iodine is specified at 150 micrograms a day. This is the minimum amount required to prevent the formation of a goiter but is far below the amount needed for a properly functioning thyroid, an optimal immune system, and other vital functions of the body.

Typically, if a patient is diagnosed with a slow functioning thyroid (hypo-thyroid) in traditional medicine, they are prescribed a synthetic thyroid replacement called Synthroid. Traditional medicine doctors often don’t even discuss that a possible reason for a patient’s slow thyroid could be a deficiency in iodine. In my private practice, almost 40% of the patients that I see have some degree of hypothyroidism and the majority of them can actually be cured with proper supplementation of iodine as opposed to relying on a drug for the rest of their lives.

Iodine and Breast Health

Iodine is also concentrated in the breast tissue in women, and a lack of it can lead to a condition called fibrocystic breast disease (painful breasts with nodules and cysts). 93% of American women have fibrocystic breast disease and the longer this disease exists, the higher the potential risk for development of breast cancer. I typically treat my patient’s with fibrocystic breast disease with iodine if they are deficient. I have treated patients that have seen dramatic results, even cured, with less then 6 months of iodine supplementation alone.

Much of the research on iodine and its relationship to disease comes from observations of populations of people in areas where iodine intake is the highest. For example it has been estimated that the mainland Japanese ingest approximately 13,800 micrograms of iodine per day, which is over 100 times the U.S. recommended daily allowance.1 Japanese people from the coastal areas ingest even more iodine than the average in-land Japanese consume. They receive much of their iodine from fresh seafood and seaweed, which is known to concentrate iodine. The Japanese, who consume a large amount of iodine by U.S. RDA standards, have remarkably lower levels of breast, endometrial, prostate, thyroid and ovarian cancer. In addition, there is a significantly lower amount of hypothyroidism and fibrocystic breast disease in Japanese women who consume more iodine.

Animal research has also shown that in an iodine-deficient state, animal breast tissue will show signs of developing breast cancer. One study showed that women who are hypothyroid (most likely due to an iodine deficiency) and are just taking thyroid hormone to correct it, are found to develop breast cancer twice as often as women not on thyroid hormones.2

How Do I Know If I’m Iodine Deficient?

Unfortunately, there are only a few doctors, including myself, in Massachusetts and Connecticut that will actually test for an iodine deficiency. Part of the reason is that many are unaware of much of the research and are so used to just prescribing drugs to treat disease as opposed to looking for nutrient deficiencies as a cause.

Before I recommend iodine supplementation to anyone, I will run a specialized urinalysis test called an iodine-loading test. This test has been found to provide very useful information on the body’s total iodine status. For the test, the patient is given a specific dose of iodine and the amount of iodine excreted in the urine over the next 24 hours is measured. If the patient has enough iodine in their body, hence not deficient, they should excrete over 90% of the iodine that was taken in, any less than that would indicate an iodine deficiency. If the patient is found to be deficient, I will typically recommend an iodine supplement with a specific dose based on the level of their deficiency.

Following supplementation, many patients see a decrease or resolution of symptoms such as fatigue, fibrocystic breast, water retention, headaches, ovarian cysts, uterine fibroids, bowel problems, dry skin and eyes, heartburn, weight gain, poor memory and elevated cholesterol.3 So if you are looking to improve your health, reduce your risk of a variety of cancers and enhance your thyroid function, find a physician (preferably a naturopathic physician) that is willing to check you for an iodine deficiency and properly treat you if you are deficient.


  1. Zava, T. T., & Zava, D. T. (2011). Assessment of Japanese iodine intake based on seaweed consumption in Japan: A literature-based analysis. Thyroid research4, 14.
  2. Wu, C. C., Yu, Y. Y., Yang, H. C., Nguyen, P. A., Poly, T. N., Islam, M. M., Iqbal, U., Khan, H., Wang, Y. C., Cheng, Y. T., Li, Y. C., & Jian, W. S. (2018). Levothyroxine use and the risk of breast cancer: a nation-wide population-based case-control study. Archives of gynecology and obstetrics298(2), 389–396.
  3. Treatment and/or results may vary based upon each patient’s unique circumstances as well as the healthcare provider’s medical judgment. Treatment plans are formulated only after a thorough discussion of the patient’s specific situation, goals, and the risks and benefits of each treatment option. Examples of treatment outcomes on this website are not intended to convey or warranty any particular outcome or benefit therefrom.