In the midst of a global pandemic, we have all been reminded how fragile life on this planet can be. We often think that we have outsmarted nature, but then nature reminds us who is boss.

But most of us have forgotten that, all throughout human history, deficiency of the essential trace mineral, iodine, was a huge and widely prevalent public health crisis–not a pandemic lasting a year or two, but millions of years of crippling health problems for millions of people around the world. Lack of iodine over time leads to goiters, enlarged thyroid glands on the front of the neck, enlarged as a compensatory response to increase the gland’s ability to extract iodine from the bloodstream. People died due to the physical mass and compression of enormous goiters that, for instance, crushed the airway. Or people died from progressive hypothyroidism (low thyroid hormone levels) that led to water retention (edema), massive weight gain, and eventually heart failure, coma (“myxedema coma”), and death. Ancient Chinese had goiters, ancient Egyptians had goiters, ancient Greeks and Romans had goiters, and they were rampant all through the Middle Ages, 19th century, and the first 20 years of the 20th century.

Because nearly all the iodine on this planet is found in the ocean, the farther inland you lived, the more likely you would be deficient in iodine. Coastal populations who regularly consumed fish, shellfish, and seaweed, or consumed plants and livestock that were coastal, generally obtained sufficient quantities of iodine. The further inland a population, however, the less likely iodine was contained in food. Areas such as the American Midwest, inland Canadian provinces like Saskatchewan and Alberta, mountainous communities in Western Europe, etc. were therefore filled with people bearing goiters and enduring hypothyroidism. Twenty percent of the population in many towns and villages had goiters. Entire villages of people standing a few feet tall, with impaired mental faculties, odd facial appearances, delayed maturation, and infertility, labeled “cretins,” could be found in inland populations.

Portrait by Eugène Trutat of a man with congenital iodine deficiency syndrome from Wikipedia/Wikimedia

(From Wikipedia)

By the early 1920, lack of iodine was identified as the cause for goiters, hypothyroidism, and cretinism. In the U.S., the FDA passed a regulation encouraging salt manufacturers to add iodine to their product, thought to be an easy and effective means to provide iodine to a then largely uneducated, rural nation. Their message: “Use more iodized salt. Keep your family goiter free!” That was actually the slogan on the Morton’s iodized salt label, too.

It worked. The rampant goiters of human history and the first half of the 20th century disappeared. Iodized salt was declared an incredible public health success story. Use more salt, use more salt.

Several decades later, Dietary Guidelines for Americans advised everyone to cut fat, saturated fat, and increase consumption of whole grains. This is a formula for sodium retention. In the face of unlimited salt intake, some people developed hypertension and other health problems. The FDA then advised Americans to slash their intake of sodium and salt–but made no mention of iodine.

So what recurs? Iodine deficiency and goiters, of course. Sure, you eat seafood once or twice per week, maybe even have the nori (sheet seaweed) on sushi once in a while . . . but that won’t do it for most. Maybe you even sneak some iodized salt into your diet, but occasional use is insufficient, especially since the canister of iodized salt only contains iodine for around 4 weeks, given iodine’s volatile nature. (Iodized salt did work when everybody in the house salted their food liberally and Mom had to buy a new canister every few weeks.)

Screen Shot 2016-03-31 at 9.16.14 AM

Iodine is an essential nutrient. It is no more optional than, say, celebrating your wedding anniversary or obtaining vitamin C. If you forget to do something nice for your wife on your wedding anniversary, I would fear for your life. If you develop open sores all over your body and your joints fall apart, you could undergo extensive plastic surgery reconstruction and joint replacement–or you could just treat the scurvy causing it from lack of vitamin C.

Likewise iodine: If you have an iodine deficiency, you experience lower thyroid hormone production, since T3 and T4 thyroid hormones require iodine (the “3” and “4” refer to the number of iodine atoms per thyroid hormone molecule; iodine atoms are circled in yellow above). This leads to lower energy (since the thyroid controls metabolic rate), cold hands and feet (since the thyroid is thermoregulatory, i.e., temperature regulating), and failed weight loss. Iodine deficiency is one of the items on the list of issues to consider if you eliminate wheat and grains with their appetite-stimulating opiate, gliadin, and high-glycemic carbohydrate, amylopectin A, and limit other carbohydrates, yet still fail to lose weight. A perfect diet will not fully overcome the metabolism-limiting effects of an underactive thyroid, whether caused by iodine deficiency or thyroid inflammation.

Given sufficient time, an enlarged thyroid gland, goiter, develops, signaling longstanding iodine deficiency. Your risk for heart attack, by the way, in the presence of a goiter is increased several-fold. Goiters are becoming increasingly common because people have been advised to reduce their salt but not obtain iodine by other means.

Iodine deficiency is common and increasing in prevalence, given the widespread avoidance of iodized salt. So what happens when you become iodine deficient? Among the effects:

  • Weight loss is stalled or you gain weight despite your efforts
  • Heart disease risk is increased
  • Total and LDL cholesterol and triglyceride values increase
  • Risk of fibrocystic breast disease and breast cancer increase (breast tissue concentrates iodine)
  • Gingivitis and poor oral health (salivary glands concentrate iodine)
  • You lack energy, sleep excessively
  • Hair becomes thin and falls out
  • Skin is dry

So how do you ensure that you obtain sufficient iodine every day? You could, of course, eat something from the ocean every day, as coastal populations such as the Japanese do. Or you could take an inexpensive iodine supplement. You can get iodine in a multivitamin, multimineral, or iodine drops, tablets, or capsules.

What is the dose? Here’s where we get iffy. We know that the Recommended Daily Allowance (RDA), the intake to not have a goiter, is 150 mcg per day for adults (220 mcg for pregnant females, 290 mcg for lactating females). Most supplements therefore contain this quantity.

But what if we ask a different question: What is the quantity of iodine required for ideal thyroid function and overall health? Ah, that’s where the evidence is sketchy. We know, for instance, that the Japanese obtain somewhere between 3,500 and 13,000 mcg per day (varying widely due to different habits and locations). Are they healthier than us? Yes, quite a bit healthier, though there may be other effects to account for this, such as a culture of less sweet foods and more salty, less wheat consumption, enthusiastic consumption of fermented foods, etc.

As is often the case with nutrients, we lack data to help us decide where the truly ideal level of intake lies. So I have been advocating intakes of 350-500 mcg per day from iodine capsules, tablets, or drops, a level that I believe is closer to the ideal intake. A very easy way to get this dose of iodine is in the form of kelp tablets, i.e., dried seaweed, essentially mimicking the natural means of intake that also provides iodine in all its varied forms (iodide, sodium iodate, potassium iodide, potassium iodate, iodinated proteins, etc.) This has worked out well with no ill effects.

The only concern with iodine is in people with Hashimoto’s thyroiditis or (rarely) an overactive thyroid nodule. Anyone with these conditions should only undertake iodine replacement carefully and under supervision (monitoring thyroid hormone levels) if a knowledgeable health practitioner is available. In autoimmune thyroid disease, iodine should not be taken until thyroid antibody levels have been normalized (by all the strategies I advocate). I have therefore had many people with Hashimoto’s normalize thyroid antibody levels, then supplement teensy-weensy doses of iodine drops, e.g., 50 mcg per day, then increase iodine intake by 50 mcg per day every few months until the desired dose is achieved. This has worked for most people without provoking hyperthyroidism (excessive thyroid hormone activity due to reactivated thyroid inflammation).

Iodine is inexpensive, safe, and essential to health and weight management. If it were a drug, it would enjoy expensive marketing and a high price tag. But it is an essential nutrient that enjoys none of the attention-getting advantages of drugs, and therefore is unlikely to be mentioned by your doctor, yet carries great advantage for helping to maintain overall health.