Iodine deficiency is on the rise again in the US. It seems hard to believe that living as we do in such an affluent culture we still have to worry about such a basic nutritional deficiency. After all, didn't we eradicate iodine deficiency back in the early part of the twentieth century? Hasn't iodizing our table salt solved the problem? Well, in a word, no. We are increasingly deficient in this nutrient, and there are some suspicions that many of our health woes--including most reproductive cancers (male and female)--can be traced back to this simple deficiency.
Iodine, of course, is important for thyroid function--and a properly functioning thyroid controls many metabolic and reproductive functions throughout the body--but iodine is important outside of the thyroid as well. All of the glands in our body use iodine in the production of hormones. In fact, iodine is the only mineral our body uses to produce hormones. In addition to the thyroid gland, many tissues throughout the body possess an iodine pumping mechanism--the breasts, stomach mucosa, salivary glands, the part of the brain that makes cerebrospinal fluid, the joints, arteries, bones, etc. Most research has focused on iodine's role in thyroid function, so in many of these other organs and glands throughout the body, little is known as to its role. We do know iodine acts as an antifungal, antiviral, antibacterial, and anticancer agent and is a potent antioxidant and detoxifier. Iodine is especially important in pregnancy, as iodine deficiency leads to poor brain development in the fetus. In fact, iodine deficiency is recognized as the leading cause of mental retardation. Even a slight deficiency during pregnancy can lead to cognitive impairment in offspring.
In studies done in the early 1970's, 2.6% of the US population were deficient in iodine. By the early 1990's that figure had risen to 11.7%. I'm not sure where it currently stands within the general population, but one recent study showed that 50% of pregnant and nursing women had an iodine deficiency. Fifty percent!
So what is causing this huge spike in iodine deficiency? There seem to be a number of causes. Prior to the 1970's, iodine was used as a dough conditioner in refined flours. A single slice of bread provided your full daily requirement of iodine. But in the early 1970's this practice stopped and manufacturers began using bromide instead. Bromide has no role in the human body (except as a suspected carcinogen) but it is in the same family of chemicals as iodine (the halogens) and will occupy the iodine receptors in the thyroid gland and elsewhere throughout the body. In other words, it bumps out iodine. And it's not just bromide that bumps out iodine--other halogens, like the fluoride in our water and the chloride in salt do so as well. So not only are we taking in less iodine than before the 1970's, what we are still getting is being blocked by the presence of bromide and other halogens. In more recent years, an additional issue is the trendiness of gourmet salts. Sea salt, kosher salt, and other trendy salts do not contain iodine. Nor does the salt typically used in processed foods or restaurant foods. Seafood has always been a reliable source of iodine in the diet, but today people are eating less seafood due to justifiable fears of mercury poisoning.
And then there's the issue of our soils. The soils of the Great Lakes region have long been recognized as the most iodine deficient soils in the world. This was one of the main reasons that iodized salt was added to the US food supply in the first place. But if you live outside of the Great Lakes region and buy locally grown food, that doesn't necessarily mean you're getting foods rich in iodine. Studies have shown that the presence of iodine in US soils has fallen 50% in the past fifty years. Not only are our bodies deficient in iodine, but our soils are as well.
If you decide to supplement your diet with iodine, you meet with some additional problems. Purnendu Dasgupta, a researcher at the University of Texas, looked at 88 samples of iodized salt and found only 53% of those met or exceeded the FDA's recommended levels of iodine. And researchers at Boston University analyzed iodine-containing prescription and OTC prenatal vitamins. Many contained less than the recommended daily amount of iodine and about one in six samples contained less than half the amount stated on the label.
So what's a person to do? Lugol's solution and Iodorol tablets are two good sources of iodine. Most physicians would consider these to be megadoses, far exceeding the FDA's recommendations, so if you do supplement with these do so under a health practitioner's care. Too much iodine can be just as much a problem as too little. I personally don't believe Lugol's solution or Iodoral are excessive--each Iodoral tablet contains the amount that the average person in Japan consumes daily in their diet (12.5 milligrams), and each drop of Lugol's is half of that. Average US consumption of iodine is 240 micrograms (0.24 milligrams) and the FDA's recommendation is a pathetic 150 micrograms per day. If you are suffering any inexplicable health issues, I'd suggest that one of the first things you take a look at is your iodine intake. It just might be something as simple as that. Personally, I can say I have totally reversed my fibrocystic breast disease by just increasing my iodine intake.