The only organ that stores large amounts of iodine is the thyroid gland, yet every cell in the body has an iodine receptor. The thyroid uses iodine and the amino acid L-tyrosine to make thyroid hormone. This is why supplementing with iodine may improve thyroid function, which in turn improves energy levels, weight maintenance, clear thinking, sharp focus and even cholesterol and hormone balance. Thyroid hormone levels also greatly influence mood, and sometimes suboptimal thyroid function is mistaken for depression. 

Iodine is especially useful for breast health. In an August 2004 study published in Breast Journal, women with fibrocystic breast disease had significant reductions in nodules (cysts) and pain when taking 6 mg of iodine per day. 

Iodine is essential for infant brain development. According to the International Council for the Control of Iodine Deficiency Disorders, iodine deficiency has multiple adverse effects on growth and development and is the most common cause of preventable mental retardation in the world. In an August 2004 study published in the Journal of Clinical Endocrinology and Metabolism, it was reported that even mild iodine deficiencies can result in lowered IQ and other neurodevelopmental problems in children. Research is just beginning to explore the role of iodine in autism, attention-deficit hyperactivity disorder (ADHD) and cognitive function. Some integrative practitioners use iodine to help with a common problem in chronic fatigue patients, informally called “brain fog.”

In fact, iodine is vital for all areas of health. Iodine is a part of a chemical family called halogens. This family contains the potentially cancer-causing compounds bromine (bromide), chlorine (chloride) and fluorine (fluoride). Iodine is not cancer-causing and has been shown to play a role in cancer prevention. However, since the family members resemble one another, these unfortunate chemicals can bind to iodine receptors. People with lesser amounts of iodine then accumulate these toxins and have increased toxic exposure. People with higher amounts of iodine can knock these carcinogens out of the body.

Iodine supplements come in a variety of forms. The thyroid prefers potassium iodide, and breast tissue prefers molecular iodine. Sodium iodide is the most soluble and may have better absorption, though more research needs to be done to confirm this. A few lesser-known forms of iodine exist as well. Dietary supplements may be a single form of iodine or a blend of two or three forms for broader effects.

The most visible sign of severe iodine deficiency is goiter, an enlargement of the thyroid that can be quite disfiguring. Iodine was added to table salt to help reduce goiter in the 1920s. However, many people no longer consume iodized salt or have reduced their table salt intake. 

Additionally, the amounts of iodine necessary to prevent goiter (150 mcg per day) are not the optimal amounts studied to improve health. In a 1998 survey published in the Journal of Endocrinology and Metabolism, researchers found that iodine levels have dropped by 50 percent in the US population from the early 1970s to the mid-1990s. Perhaps of even more concern is a survey from 2005 to 2008, which found that 57 percent of pregnant women had suboptimal iodine levels. Other factors that play a role in reducing our iodine status include the substitution of chlorine for iodine in water purification, the introduction of fluoridated water and toothpastes and the switch from iodine as a dough conditioner to brominated flour in commercial baked goods.

The most plentiful food sources of iodine are sea vegetables and the fish that eat the sea vegetables. Japanese people who eat a traditional diet are estimated to consume more than 13 mg (13,000 mcg) of iodine daily. That is more than 100 times greater than the minimum levels set to prevent goiter. Residents of Okinawa, who consume even greater levels of iodine than other Japanese residents, enjoy the longest life span and the lowest chronic disease rate in the world, according to statistics collected by the World Health Organization and the Japan Ministry of Health and Welfare. While many factors play a role in promoting their health and vitality, some experts believe that higher levels of iodine in the diet are an important part of this extraordinary level of health. 

Studies on fibrocystic breast disease have used as little as 3 to 6 mg to yield significant results. In his book Iodine: Why You Need It, Why You Can’t Live Without It, David Brownstein, MD, a doctor and iodine expert, recommends 50 mg a day for three months, with reductions to 6.25 or 12.5 mg a day thereafter, depending upon the individual’s health concern. However, many health experts recommend working with an integrative medical practitioner before supplementing at higher levels to make sure there are no contraindications for doing so.

Iodine is an important mineral, and deficiency can lead to a myriad of health problems, some of which can be life-threatening. Intelligent use of iodine supplementation can make a real difference in health and vitality.

Editor's Note: Doses of iodine in excess of 0.5 mg/day may decrease thyroid function so please talk to your doctor before taking daily high doses of iodine.