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The following article is a full chapter excerpted from Byron Richards’ book, 21st Century Thyroid.
The Power of Iodine
The importance of iodine to the formation of thyroid hormone is widely acknowledged. Its importance to the efficient function of many aspects of human health is drastically under-appreciated. We will take a deeper look at iodine in this book, compared to other nutrients, because it is a very misunderstood nutrient that can help make a tremendous difference in your quality of health.
For the past century, Western medicine has sought to minimize the importance of iodine. The main reason for this is that the doctors of the nineteenth century used iodine, in very high doses, for all manner of health problems. It was so effective that it was typically employed as a first option, as well as for any problem that was not resolving as expected. This natural remedy was considered to be extremely undesirable competition by those sponsoring the emerging profit system of Western medicine. It is only recently that science is beginning to understand the mysterious healing powers of iodine.
Thyroid Hormones Are Made of Iodine
Your thyroid gland is in the business of making, storing, and releasing thyroid hormones. You absolutely must have adequate iodine to make thyroid hormones, resulting in the production of the two main thyroid hormones, T4 (thyroxin) and T3 (triiodothyronine).
T4 is one molecule of the amino acid tyrosine with four iodine atoms attached. It is considered the inactive form of thyroid hormone. T3 is one molecule of tyrosine with three iodine atoms attached. Iodine is sixty-five percent of the molecular weight of T4 and fifty-nine percent of T3.
T3 is the active form of thyroid hormone that guides metabolic activity in the cells of your body. Your thyroid gland typically releases eighty percent T4 and twenty percent T3 into your bloodstream to sustain baseline levels of thyroid hormones. Inactive T4 is eventually converted to active T3 within your cells by a deiodinase enzyme.
There are different types of deiodinase enzymes, which remove or reposition the iodine atoms on thyroid hormones. One form can remove an iodine atom from T4 to make the biologically active T3. Another type of deiodinase enzyme can also remove iodine from T4 or change the position of iodine on active T3 to produce reverse T3 (rT3), which is your natural braking system. Your cells have an elaborate stop and go system. T3 is go, rT3 is stop.
Lab tests measure T4 fairly well, but the basic lab test for T3 is actually the sum of active T3 and rT3. This means the go signal (T3) and the stop signal (rT3) show up as one score, which has limited usefulness other than to quantify the total amount of both of them. All these different forms of thyroid hormones are defined by how much iodine they have and how the iodine is positioned.
Small amounts of iodine, as little as 70 micrograms (mcg) per day, can prevent goiter and other thyroid pathology. This is enough iodine for a thyroid gland to barely get by. A far different question is the amount and type of iodine needed for the efficient production of thyroid hormones by the thyroid gland, as well as for satisfying the other important needs for iodine elsewhere in your body. Healthy people have somewhere between 25 and 50 milligrams (mg) of total iodine in their body. Fifty to seventy percent of this is not in the form of thyroid hormones and is concentrated outside of the thyroid gland.
Thyroid Gland Evolution Is a Bottom-up Design
The metabolic evolution of thyroid hormones to their current level of human sophistication took place over millions of years. The human body as we know it today did not start out with a top-down design, wherein the brain and thyroid gland had a master plan as to how they would use iodine and thyroid hormones, and all else would fall into line. Rather, advancements in how life forms handled iodine over millions of years eventually led to the current human metabolic function of thyroid hormones. We tend to think of iodine as part of the seemingly more important thyroid hormones. Evolution most likely had this the other way around, wherein the metabolism of thyroid hormones was simply an advanced method of iodine utilization, only a subset of overall iodine metabolism in your body.
As primitive life moved from the ocean and developed mobility on land, it moved farther and farther away from natural sources of iodine. The thyroid gland first evolved as a reservoir for storing iodine. T4 has always played an important role in iodine nutrition, first evolving to help manage the distribution of iodine around the bodies of early life forms, as distinct from the function of thyroid hormones as we know it today.
As life forms became more complex and needed larger amounts of energy to function, the thyroid gland became more sophisticated. So did the iodine-distribution and cell-metabolism mechanisms. Over millions of years, evolution enabled progressively more advanced uses of iodine within cells, eventually resulting in the highly superior version of thyroid hormones and iodine metabolism found in Homo sapiens.
Forms of Iodine
Iodine is a nonmetallic element that is quite unstable unless it is connected to another atom or molecule. It is a very large atom, with fifty-three protons in the nucleus. Its size makes it one of the “heaviest” atoms used in the human body. It has high electronegativity and one valence electron in its outer shell, making it quite reactive with other atoms and molecules. This means it can easily form chemical relationships with many substances in living cells. Iodine excels at these relationships, like a person who is really good at networking and social media. Because of its large size, iodine forms relatively weak bonds, meaning it does not get too fixed in place and is good at mingling at the party. Due to its unique ability to move about, I call iodine the “master magician” nutrient. It readily takes on different molecular configurations and forms relationships with other nutrients, as well as with toxic substances.
Our bodies harness the power of highly reactive iodine by using forms of iodine that are bonded to another atom or molecule, enabling iodine to be biologically useful. In one of its roles as master magician, iodine can form iodides with many elements. An iodide (I-) is a molecular relationship that has an extra electron (compared to the total number of protons). An iodide is a negatively charged ion (anion). This means it is really good at participating in free radical and antioxidant reactions. The most common iodide in human nutrition is potassium iodide (KI).
Another iodine relationship occurs when one atom of iodine bonds to another atom of iodine, like shaking hands in the mirror. Two iodine atoms bond together to form I2, commonly referred to as molecular iodine. Molecular iodine is friendlier than potassium iodide to the insides of cells, since the outer valence electron in each iodine atom is shaking hands with its counterpart, instead of being potentially reactive.
Potassium iodide can be converted to molecular iodine in your body, which requires peroxidase enzymes. Peroxidase enzymes are like carpenters that require energy and metabolic resources. In comparison, it requires no such metabolic expense to convert molecular iodine to potassium iodide, which is how extra iodine is removed from your body.
Molecular iodine forms relationships with other molecules by accepting electrons. It can bind to toxic substances, helping to remove them from your body. It can also bind to potassium iodide, forming I3-. More I2 molecules can be attached, in turn reacting with other molecules in a bewildering array of possibilities. These relationships include a wide range of cellular and gene components, as well as many nutrients. Importantly, molecular iodine is a vital nutrient for the proper function of your genes, expanding its role well beyond thyroid hormones.
Molecular iodine and potassium iodide are inorganic forms of iodine, because the molecules lack carbon. When iodine combines with a carbon-containing molecule (a molecule synthesized in a biological system), it is called organic iodine. Iodine in humans readily combines with carbon-containing amino acids or fatty acids, forming organic iodine compounds. One example of an organic iodine compound is thyroid hormone, wherein iodine is bound to the amino acid tyrosine. Iodine also binds to the amino acid histidine, which helps move iodine around your body on histidine-rich transport proteins that are commonly present in your blood. It can also combine with histidine-rich antioxidants like carnosine, which protects your brain, heart, and muscles. It can bind to milk proteins in breast tissue. When iodine is bonded to a protein it is called an iodinated protein.
New scientific tools enable us to see that iodine is used in every cell of your body, in many different ways. The main point to understand is that molecular iodine is a mover and a shaker, the life of the party.
Oxygenation of Earth
The atmospheric oxygen of Earth is required for human life. Plants produce oxygen in the process of photosynthesis, using energy from the sun to convert carbon dioxide and water into carbohydrates and oxygen. But how did this get started in the first place? How did life forms evolve to be in harmony with oxygen? As it turns out, iodine is a major player in the oxygen evolution game.
Planet Earth is approximately 4.5 billion years old. Rock and fossil records prove that Earth had a significant oxygen-containing atmosphere 2.45 billion years ago. It is likely that bacteria used photosynthesis to start producing oxygen in larger amounts as far back as 3.5 billion years ago, and for almost a billion years the oxygen reacted with volcanic gases, various minerals, and large amounts of iron in the atmosphere. Not until these highly reactive substances were oxidized did oxygen fill the atmosphere.
The first forms of life on Earth were very simple, single-cell bacteria that did not have a nucleus. These first cells lived in a no-oxygen environment. They evolved into bacteria that used photosynthesis to make oxygen. The most primitive cell type in this category is blue-green algae (cyanobacteria). Even though seawater contains only small amounts of iodine (0.05 parts per million), blue-green algae has a penchant for accumulating iodine. Blue-green algae and its evolutionary children are the primary sources of oxygen for Earth’s atmosphere, continuing to play a vital role in the biosphere up to the current day. The primary cells that have oxygenated Earth have 3.5 billion years of genetic experience with iodine on board. It would be foolish to think that iodine is not crucial to any living cell that depends on high levels of oxygen metabolism, including human cells.
Blue-green algae eventually evolved into multicellular structures such as kelp. Kelp is brown-algae large seaweed. Its cells have a nucleus and other cellular compartments, making them more advanced than simple, single-cell blue-green algae. Kelp is the most effective accumulator of iodine of any life form, yet it was not until 2008 that iodine metabolism within kelp was better understood, including its specific antioxidant function.
In a non-stressed state, kelp accumulates iodine in the form of potassium iodide and concentrates it in the cell wall (not inside the cell). The potassium iodide does not form chemical bonds within the cell wall; rather, it is held in place via its ion charge, which forms harmonious associations with carbohydrates, polyphenols, or proteins that make up the cell wall. This is interesting because iodide ions can easily become reactive, yet primitive algae figured out how to keep them in a useful “at rest” condition. This is like keeping soldiers with their feet up in the barracks, waiting for a call to arms.
Iodine as an Antioxidant
When kelp comes into contact with a stressor, then iodide swings into action as the front line of defense. One of its antioxidant functions is to neutralize ozone. It does this by producing large amounts of molecular iodine that are then released into the air, forming small particles of iodine oxides, in turn helping cloud formation. This is a fascinating link between a biological antioxidant system and weather. It is also interesting that humans living along seaweed-rich coastal areas inhale molecular iodine in nutritionally relevant amounts, an important aspect of human evolution.
Researchers have exposed kelp to the signs of a bacterial germ gang (biofilm), indicating to the algae that it is about to come under infectious attack. In response, the kelp releases large amounts of hydrogen peroxide (H2O2) from its outer cell wall, along with potassium iodide. This large germ-killing oxidative burst, like firing a shotgun at the bacteria, peaks within thirty minutes and returns to baseline three hours later. Iodine is essential for regulating the assault, helping to kill the germs while controlling the oxidation process (preventing the gun from backfiring).
These researchers point out that the unique chemistry of iodine enables it, as an antioxidant, to neutralize a variety of free radical reactions that can occur when it deals with hydrogen peroxide, ozone, hydroxyl radicals, and superoxide. This makes iodine a very versatile antioxidant. It is highly likely, since humans process large amounts of hydrogen peroxide and oxygen while making energy, that the evolutionary antioxidant lessons of iodine help us with superior energy production within our cells.
Scientists now estimate that molecular iodine has fifty times the antioxidant power of potassium iodide and ten times the activity of vitamin C. While the precise mechanisms of the antioxidant activity of different forms of iodine remain to be elucidated, there is no question that iodine, especially molecular iodine, is a potent antioxidant.
Iodine as an Energy-sparing Nutrient
Living cells are always looking for the most energy-efficient way to handle a task or problem, one more example of my theme of efficiency. There are numerous organic antioxidants, including vitamin C, isoprenoids, polyphenols, and glutathione. These are metabolically and energetically expensive to make.
In the case of kelp, these organic antioxidants are used by the inside of kelp cells to sustain life, whereas iodide is concentrated in the cell wall. These organic antioxidants would be capable of interacting with any stressful oxygen situation, but in doing so they could be depleted too rapidly, in turn compromising survival. Experiments show that these organic antioxidants are not used to combat the stressful encounters of kelp with the environment.
Rather, inorganic iodide is used. Inorganic iodine requires no energy to produce and is available from seawater. Thus, the ability to use it as a front-line defense is an energy-sparing survival strategy that kelp developed.
The researchers went on to show that iodine is nontoxic to human white blood cells of the immune system, and that it helps control the oxidative burst of germ-killing neutrophils. This means that human front-line immune troops, evolving from ancient systems of protection, have learned to use iodine in manners similar to evolutionary principles of kelp. It is likely that human immune cells have learned to use iodine in even more sophisticated ways than kelp does, especially for front-line immunity.
Algae use a peroxidase enzyme to convert the reactive potassium iodide into the friendlier molecular iodine, which can then diffuse into the cell. From a cell’s point of view, potassium iodide is a bit of a hot potato, better kept at arm’s length and used for aggressive defense purposes. It is like having an ornery watchdog on patrol in the yard, one that is not suitable to be in the house with the kids. The kids like a friendlier pet, molecular iodine.
It stands to reason that if iodine is lacking for cellular nutrition, then other organic antioxidants will be called upon and used up faster. A study back in 1984 showed that T4 and rT3 give up their iodine to stop free radicals coming from rancid lipids. This means that the iodine in thyroid hormones could be diverted for antioxidant purposes instead of for thyroid hormone, a backup system for helping the body cope with rising levels of free radical damage. It makes sense that an optimal intake of iodine for cellular nutrition would be a foundation for the entire antioxidant team, sparing organic antioxidants for more advanced antioxidant chores.
It is likely that the harder cells must work or the faster they metabolize (meaning more oxygen is used), the higher the need for iodine as basic protection. Before iodine was discovered, there were many theories about what caused goiter. The Germans had the theory that goiter could be triggered by hard work, an observation that occurred because their hard-working people were often borderline iodine deficient. This observation is consistent with the idea that the need for iodine within cells increases as cells work harder.
Free radical damage increases as health declines or as part of the typical process of aging. General signs of wear and tear, increased demands of stress, any poor health condition, and the condition of being overweight all imply that antioxidants are being used up faster and may be lacking. If iodine follows its evolutionary pattern, it could well be an antioxidant of first resort, since inorganic iodine is metabolically inexpensive for your body to use in an effective antioxidant role.
The modern research shows that iodine is involved in the most fundamental processes of life: helping to guide the safe use of oxygen, as well as enabling the oxygenation of Earth’s atmosphere; even influencing cloud formation and weather. Humans have the most advanced cellular system of iodine-utilization known. While there are many actions of iodine in cellular metabolism, it is now clear that contributing to the antioxidant team is one of them. Indeed, the ability to use iodine in cells significantly improves the capability for energy production and is a defining feature of superior human-survival advantage.
Iodine and the Evolution of Intelligence
Modern iodine knowledge provides thought-provoking insights on the evolution of human intelligence. A devastating problem occurs in the womb during nervous system development if iodine is lacking. Serious deficiency results in irreparable brain damage called cretinism. Less serious deficiency lowers IQ, reducing human potential.
Iodine in the fetus is taken up by the choroid plexus, a core brain structure required for brain formation. We do know that the need for iodine at this crucial time of brain development exists not to increase the rate of thyroid metabolism in the developing fetus. To the contrary, the placenta is loaded with deiodinase enzymes that prevent excess metabolic activity of thyroid hormones. This guards the fetus against surges of thyroid hormone that could be coming from the mother. While small amounts of thyroid hormone are needed for the first three months of neurological development, those levels are indeed small.
Although the details are not clear, it appears that iodine provides antioxidant protection and/or crucial cell regulation for nervous system development. The fetus’s thyroid gland is formed by week eleven or twelve and begins to secrete hormones at week sixteen. Fetal thyroid hormones are then augmented with the mother’s supply of thyroid hormones in order to obtain full-term growth. These higher levels of thyroid hormones are occurring from week sixteen onward. And, of course, this higher metabolic level of thyroid hormones requires iodine.
It is truly unfortunate that severe iodine deficiency in many poor areas of the world continues to result in the condition of cretinism (severely stunted physical and mental growth, and major handicaps). Still, five million people suffer from cretinism.
While cretinism marks the far end of the iodine-deficiency spectrum during pregnancy, varying degrees of a lack of iodine during fetal development result in reduced IQ. Thirty percent of the world’s population is at risk for significant iodine deficiency. A lack of iodine during fetal development can also cause poor development of the thyroid gland, contributing to poor thyroid function in later life. Some of these thyroid problems can be managed with nutrition, and medication when needed. However, it is difficult to correct the brain structures that did not form in an optimal way in the womb. There is an important window of opportunity for iodine to work its magic. If that opportunity is missed, it cannot be corrected at a later time simply by taking iodine.
Americans have been lulled into thinking that this is a problem of developing countries; far from it. While cretinism in America is rare, a lack of iodine is associated with the obesity epidemic, the epidemic of prematurely born babies, miscarriages, and with too many children born with reduced potential for optimal intelligence.
A Major Iodine Discovery Rewrites History
In 1996 an advanced system of iodine uptake into the thyroid gland, as well as into other key body areas such as the choroid plexus and digestive system, was discovered. It is called the sodium-iodine symporter (NIS). NIS enables top-priority areas of your body to grab iodine from the circulation before other, less important areas can get it. This is an evolutionary first-dibs system, since iodine has often been scarce during our evolutionary development.
The importance of NIS was immediately obvious to evolutionary researchers, and in 1998 exhaustive research was published documenting the identical skeletal nature of Neanderthals and modern-day cretin humans. The theory was persuasively put forth that a singular genetic advancement resulted in an advanced NIS system in Homo sapiens. This enabled the development of a superior thyroid gland, which led to the evolution of higher intelligence, allowing modern humans to take their place above Neanderthals.
In addition to being active in the digestive system, brain, and thyroid gland, NIS is also known to be active in the male reproductive system (testes and prostate), female reproductive system (ovaries, endometrial glands, and placenta), lactating mammary glands, skin (another defense barrier), pancreas (blood sugar metabolism), bronchial airway, lungs, thymus gland (immunity), salivary glands, lacrimal glands (eyes), bladder, gallbladder, and kidneys. It is likely that other tissues expressing NIS will be identified as time moves along, especially as techniques for identifying NIS activity improve.
All we know for sure is that when NIS is activated in any one of these body tissues, it wants iodine, once again demonstrating a diverse need for iodine. Based on the emerging picture of iodine as a nutrient fundamental to cellular processes, it may well be that symptoms of poor function relating to any of these body tissues may be caused, at least in part, by a deficiency of iodine. Skin problems and female complaints are typical symptoms of hypothyroid, and it may well be that iodine deficiency is causing them to become manifest.
It is clear from the NIS-expressing tissues thus far identified that a primary role of iodine is to protect any surface of the body which comes into contact with the outside world, including skin and mucosal linings of digestion, the urinary tract, eyes, female reproductive system, and breathing. It is noteworthy that the majority of hypothyroid symptoms could manifest entirely as a result of iodine deficiency, as distinct from a deficiency of thyroid hormones. This means that restoring the intake of iodine to an optimal level could go a long way toward clearing up symptoms which may otherwise appear to be hypothyroid symptoms.
Competition for Iodine
Your body is very good at using nutrients for multiple duties. This sets up a situation of competition for the nutrients within your body. For example, NIS is active in many tissues, taking up iodine to help your eyes, sinuses, mouth, respiratory system, skin, digestive tract, and reproductive system. These areas of need will compete with your thyroid gland and brain for iodine.
Even if all these areas are doing pretty well, they all still require some iodine for baseline needs. However, if one or more of these areas is struggling, then the need for iodine rises. This type of issue is not taken into account by government officials when setting guidelines for iodine intake.
Once you drop below an optimal level of intake for a nutrient, then your body is forced into a juggling act, trying to distribute what little you have to multiple areas of need. In other words, not only do you need to water the lawn, you also need to water the flowers, shrubs, and trees. This is never a desirable state of affairs if you are short on water. In the case of iodine, this type of problem has typically been going on for years before a medically diagnosable thyroid problem finally raises its hand.
Complicating matters is that stressed thyroid glands often have weakened structure, resulting in a “leaky” problem. This means that iodine entering the gland can leak out inappropriately, and therefore higher iodine intake is needed.
If you are struggling with thyroid symptoms and any type of health issue relating to your brain, eyes, sinuses, mouth, respiratory system, skin, digestive tract, or reproductive system, then you are likely to benefit from a higher intake of iodine.
Potassium Iodide
We know a fair amount about how potassium iodide is absorbed and transported in your body, as a result of the common use of radioactive iodides in medical imaging and thyroid cancer treatment.
One role of NIS is to absorb iodides from the small intestine into your bloodstream. Over ninety percent of iodides that reach the small intestine are absorbed, indicating the high priority placed on getting this nutrient into your body.
The thyroid gland has the strongest NIS system, meaning it will take up iodides from your bloodstream better than any other organ system. TSH (thyroid stimulating hormone) acting on NIS turns up the NIS volume knob on your thyroid gland, ensuring that the thyroid gland gets the iodine it needs. Other body tissues that use NIS to absorb iodine do not respond to TSH, because during evolution they were created before the thyroid gland and have no TSH receptors.
As iodide enters your circulation, it goes into solution with blood plasma and is taken up by red blood cells. Iodide easily goes in and out of red blood cells. Within ten minutes the red blood cells transport iodide to the fluid surrounding cells throughout your body. It does not enter most cells in the iodide form. The rapid accumulation of iodides in the red blood cells, blood plasma, and extracellular tissue spaces forms an iodide pool, a dynamic reservoir of this important nutrient.
What is not used by your body tissues then travels back into the circulation and is processed by your kidneys. About thirty percent of iodides are filtered into the urine and excreted, even if iodine is lacking. High doses of iodide are quickly excreted by the kidneys. Radioactive iodide rapidly accumulates in the kidneys following ingestion, because the kidneys are trying to filter excess iodides out of the body. Within several hours, the higher levels of radioactive iodide are removed by the kidneys, returning kidney iodide levels to a baseline amount. Ninety percent of the removal of iodine from the body is due to ongoing kidney clearance of iodides.
A number of important insights can be deduced from these findings. The fact that iodides are rapidly spread to the fluids between cells all around the body speaks to the importance of iodine, independent of thyroid hormone, for your body as a whole. There is absolutely no way your body would quickly transport a substance almost everywhere unless there was a potential need.
We know that immune cells which are fighting infection can use iodide to make weapons to kill germs. It makes sense that this system of iodide distribution would be an effective way to keep the ammunition supply lines functional. A deficiency of iodide would impair optimal immune function, especially during times of battle.
Iodides can be converted to molecular iodine. This enables cells to uptake this friendlier form of iodine for internal cellular use. Molecular iodine diffuses into cells and does not use NIS. Only iodides use NIS. It stands to reason that ingested iodides are rapidly deployed so that if cells need iodine, they will be able to convert iodides to help out. Iodides may not be the preferred form of iodine for internal cell use, but they are a common nutritional form, one that has been around since life evolved, and cells have learned to use them for survival advantage.
Any extra iodides that aren’t used rapidly head to the kidneys, with a continual percentage of them being flushed out. While iodides have nutritional value, they are also the preferred “waste product” form of iodine. When iodide levels are high, they are cleared out rapidly. More normal amounts of iodide are continuously cleared out at a slower pace. Molecular iodine is converted to potassium iodide in order to be cleared out.
The fact that red blood cells rapidly take up and release iodide is also quite interesting, whereas T4 and T3 are not taken up by red blood cells. Red blood cells are the only cells in the human body that do not have mitochondria, meaning they do not make energy by oxygen-combustion methods and do not have advanced repair mechanisms. This is why red blood cells are replaced every four to six weeks; they get worn out doing what they are doing and have no way to fix themselves. Red blood cells don’t need to worry about having iodides inside, since key cell components for advanced oxygen-based energy production do not exist in them and therefore cannot be damaged by iodides.
Red blood cells also carry iron in their hemoglobin. Iron is vital for health and is needed for cellular T3 activity. However, iron is potentially far more reactive than iodides in terms of generating free radicals. Iron is a true double-edged sword. Having iodides on board red blood cells would actually help protect against any iron that was inappropriately leaking out of red blood cells during the transport process. One of the great evolutionary purposes of iodides was to reduce the oxidizing power of iron in Earth’s early atmosphere. It is quite likely that red blood cells have learned to use iodides to help manage iron issues which would otherwise be stressful.
The Extreme Importance of Molecular Iodine
In comparison to radioactive iodides, there is far less research on molecular iodine. The first efforts in this regard occurred under the funding of NASA in the 1990s, when they were considering using molecular iodine to purify drinking water on space flights. While some molecular iodine is converted to potassium iodide under the influence of hydrochloric acid in the stomach, not all of it is. This was the first research to prove that much of ingested molecular iodine was absorbed as molecular iodine by diffusing across the digestive lining and into the blood. Once in the blood, molecular iodine readily interacts with blood components, forming useful relationships with proteins, fatty acids, and cholesterol, much more than do iodides. Molecular iodine is not taken up by red blood cells. It easily catches a ride on other compounds in the bloodstream and hops off when desired. This research showed that in healthy young men, several weeks of very high iodine intake (up to 70 mg per day) caused no statistically significant changes in T3, T4, or TSH. The intake of molecular iodine was cleared within eleven days following the end of the study, captured as potassium iodide in urine. This study proved molecular iodine is eventually converted to potassium iodide for removal from the body.
A research group from Mexico has done the most to understand the differences between molecular iodine and potassium iodide for cellular and breast health. They have shown in animal and cell studies that iodide is converted to molecular iodine, in turn forming iodolactones. These iodolactones occur when molecular iodine bonds to long-chain unsaturated fatty acids, such as arachidonic acid (AA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA). EPA and DHA are known as essential fatty acids and are quite popular as dietary supplements for cardiovascular, metabolic, eye, and brain health. Iodolactones reside in the outer cell membranes as well as in the membranes of various cellular components. Of immense importance is that iodolactones regulate gene signals of the cell and are intimately involved with growth factors and the cell signaling. These are the very same gene signals that are involved with keeping cells healthy and not making too many half-dead cells.
The Mexican researchers have shown that molecular iodine reverses abnormal tissue and cystic changes in breast tissue, whereas iodide does not. They have proven that molecular iodine is taken up rapidly by cells, within five to fifteen minutes after intake, whereas iodide is not. Molecular iodine uptake is dependent on cellular protein metabolism (gene activity) but not on cellular energy production. Uptake into cells is by diffusion and not by NIS.
Recently, these researchers issued a paper explaining the safety of molecular iodine in higher doses and its highly protective benefits for the thyroid gland, breast tissue, prostate, brain, and digestive system. They are specifically calling for a change to international public-health proclamations for iodine, recommending at least 3 mg of molecular iodine per day for individuals with health concerns that are highly benefited by molecular iodine.
How Much Iodine Is Safe?
The question of the safety of high-dose iodine depends on a number of variables, including the form of iodine ingested, adequacy of related nutrients, and health of the individual. People in better health are likely to tolerate very large amounts of iodine quite well, whereas for those in poorer health some issues may arise. Because it is those in poorer health who are most likely to try high-dose iodine as a remedy for their problems, a better understanding of the risks and benefits should guide potential use.
In healthy individuals with no history of medically defined thyroid problems, iodine in any form appears to be well tolerated up to 30 mg per day. With higher doses, mostly as potassium iodide, there is an inhibitory effect on the release of T4 and T3 from the thyroid gland. Doses up to 300 mg of potassium iodide per day have been tested in healthy men, with only slight changes in thyroid hormone levels occurring; these levels revert to normal two weeks following the removal of iodine intake. Iodides in high doses may slightly interfere with the release of thyroid hormone in healthy people.
It appears that a minimum of 3 mg of molecular iodine per day is needed to support health issues involving the prostate or breasts; with 6 mg of molecular iodine per day being more beneficial than 3 mg. Doses below that level do not appear helpful. No side effects to the levels of thyroid hormones have been observed at these levels of intake.
Dosing of 9 to 12 mg of molecular iodine per day showed similar benefits but also some side effects, including interference with the release of thyroid hormones in twenty percent of patients. Side effects disappeared when iodine was discontinued.
The human studies on potassium iodide and molecular iodine do not explore the simultaneous use of synergistic nutrients that are needed for proper iodine metabolism. Thus, iodine as a singular supplement in healthy people is quite safe for most in doses up to 30 mg per day, especially in the form of molecular iodine. It is obvious that the use of synergistic nutrients will enhance iodine utilization, but no studies on this subject have been conducted.
In individuals with existing problems of the thyroid gland, the use of iodine is more complex. On the one hand, deficiency of iodine and other nutrients in the first place underlies the development of most problems within the thyroid gland. However, now that problems exist, it is like having a sprained thyroid gland. In general, this means taking lower doses of iodine along with comprehensive nutritional support to build up fitness of the thyroid gland. Slowly, over time, the dose of iodine can be increased. It is similar to conditioning yourself to jog five miles a day when, at your starting level of fitness, you have trouble jogging six blocks.
Virtually any study warning against higher iodine intake is based on populations of people with endemic thyroid problems, including a deficiency of iodine as well as many other needed nutrients. That is not a relevant patient population on which affluent Western countries should base iodine recommendations. That said, any person with a medical history of thyroid problems has evidence of a sprained thyroid. In this situation, the primary fuel for the production of thyroid hormones may not work well in high doses, due to the inherent limitations of the struggling gland. The short- and long-term goal is not to avoid iodine but to get it to work in a healthy way within the thyroid gland, starting with smaller amounts.
Iodine supplementation will always work best as part of a comprehensive nutrient-support program. When in doubt, proceed slowly and build your health gradually. There is tremendous potential for health improvement with higher intake of iodine.
Covering Your Iodine Basic Needs
When it comes to iodine, the Institute of Medicine’s Food and Nutrition Board recommends 150 micrograms (mcg) of iodine for adults, 290 mcg for lactating women. This is often enough to prevent the blatant malfunction of thyroid hormones that can result in goiter, cretinism, or other thyroid pathology. It is enough for the thyroid gland to limp along, while apparently leaving some dog-bone scraps for other iodine needs in your body.
These U.S. officials think the safe upper limit for iodine is 1 mg per day (1000 mcg), a guideline rooted in public-health paranoia and denial of iodine science. There isn’t even a passing thought given to the quality of the iodine consumed, thus, encouraging people to consume iodized salt to cover their iodine needs.
Interestingly, millions of Japanese safely consume up to 5 mg of iodine per day from a variety of fresh seaweed sources, thirty-three times the official U.S. government guidelines and far higher than their arbitrary “safe upper limit.” Fresh seaweed contains several forms of iodine, including potassium iodide, molecular iodine, and iodate (iodine attached to three oxygen atoms - IO3
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The Power of Iodine
The importance of iodine to the formation of thyroid hormone is widely acknowledged. Its importance to the efficient function of many aspects of human health is drastically under-appreciated. We will take a deeper look at iodine in this book, compared to other nutrients, because it is a very misunderstood nutrient that can help make a tremendous difference in your quality of health.
For the past century, Western medicine has sought to minimize the importance of iodine. The main reason for this is that the doctors of the nineteenth century used iodine, in very high doses, for all manner of health problems. It was so effective that it was typically employed as a first option, as well as for any problem that was not resolving as expected. This natural remedy was considered to be extremely undesirable competition by those sponsoring the emerging profit system of Western medicine. It is only recently that science is beginning to understand the mysterious healing powers of iodine.
Thyroid Hormones Are Made of Iodine
Your thyroid gland is in the business of making, storing, and releasing thyroid hormones. You absolutely must have adequate iodine to make thyroid hormones, resulting in the production of the two main thyroid hormones, T4 (thyroxin) and T3 (triiodothyronine).
T4 is one molecule of the amino acid tyrosine with four iodine atoms attached. It is considered the inactive form of thyroid hormone. T3 is one molecule of tyrosine with three iodine atoms attached. Iodine is sixty-five percent of the molecular weight of T4 and fifty-nine percent of T3.
T3 is the active form of thyroid hormone that guides metabolic activity in the cells of your body. Your thyroid gland typically releases eighty percent T4 and twenty percent T3 into your bloodstream to sustain baseline levels of thyroid hormones. Inactive T4 is eventually converted to active T3 within your cells by a deiodinase enzyme.
There are different types of deiodinase enzymes, which remove or reposition the iodine atoms on thyroid hormones. One form can remove an iodine atom from T4 to make the biologically active T3. Another type of deiodinase enzyme can also remove iodine from T4 or change the position of iodine on active T3 to produce reverse T3 (rT3), which is your natural braking system. Your cells have an elaborate stop and go system. T3 is go, rT3 is stop.
Lab tests measure T4 fairly well, but the basic lab test for T3 is actually the sum of active T3 and rT3. This means the go signal (T3) and the stop signal (rT3) show up as one score, which has limited usefulness other than to quantify the total amount of both of them. All these different forms of thyroid hormones are defined by how much iodine they have and how the iodine is positioned.
Small amounts of iodine, as little as 70 micrograms (mcg) per day, can prevent goiter and other thyroid pathology. This is enough iodine for a thyroid gland to barely get by. A far different question is the amount and type of iodine needed for the efficient production of thyroid hormones by the thyroid gland, as well as for satisfying the other important needs for iodine elsewhere in your body. Healthy people have somewhere between 25 and 50 milligrams (mg) of total iodine in their body. Fifty to seventy percent of this is not in the form of thyroid hormones and is concentrated outside of the thyroid gland.
Thyroid Gland Evolution Is a Bottom-up Design
The metabolic evolution of thyroid hormones to their current level of human sophistication took place over millions of years. The human body as we know it today did not start out with a top-down design, wherein the brain and thyroid gland had a master plan as to how they would use iodine and thyroid hormones, and all else would fall into line. Rather, advancements in how life forms handled iodine over millions of years eventually led to the current human metabolic function of thyroid hormones. We tend to think of iodine as part of the seemingly more important thyroid hormones. Evolution most likely had this the other way around, wherein the metabolism of thyroid hormones was simply an advanced method of iodine utilization, only a subset of overall iodine metabolism in your body.
As primitive life moved from the ocean and developed mobility on land, it moved farther and farther away from natural sources of iodine. The thyroid gland first evolved as a reservoir for storing iodine. T4 has always played an important role in iodine nutrition, first evolving to help manage the distribution of iodine around the bodies of early life forms, as distinct from the function of thyroid hormones as we know it today.
As life forms became more complex and needed larger amounts of energy to function, the thyroid gland became more sophisticated. So did the iodine-distribution and cell-metabolism mechanisms. Over millions of years, evolution enabled progressively more advanced uses of iodine within cells, eventually resulting in the highly superior version of thyroid hormones and iodine metabolism found in Homo sapiens.
Forms of Iodine
Iodine is a nonmetallic element that is quite unstable unless it is connected to another atom or molecule. It is a very large atom, with fifty-three protons in the nucleus. Its size makes it one of the “heaviest” atoms used in the human body. It has high electronegativity and one valence electron in its outer shell, making it quite reactive with other atoms and molecules. This means it can easily form chemical relationships with many substances in living cells. Iodine excels at these relationships, like a person who is really good at networking and social media. Because of its large size, iodine forms relatively weak bonds, meaning it does not get too fixed in place and is good at mingling at the party. Due to its unique ability to move about, I call iodine the “master magician” nutrient. It readily takes on different molecular configurations and forms relationships with other nutrients, as well as with toxic substances.
Our bodies harness the power of highly reactive iodine by using forms of iodine that are bonded to another atom or molecule, enabling iodine to be biologically useful. In one of its roles as master magician, iodine can form iodides with many elements. An iodide (I-) is a molecular relationship that has an extra electron (compared to the total number of protons). An iodide is a negatively charged ion (anion). This means it is really good at participating in free radical and antioxidant reactions. The most common iodide in human nutrition is potassium iodide (KI).
Another iodine relationship occurs when one atom of iodine bonds to another atom of iodine, like shaking hands in the mirror. Two iodine atoms bond together to form I2, commonly referred to as molecular iodine. Molecular iodine is friendlier than potassium iodide to the insides of cells, since the outer valence electron in each iodine atom is shaking hands with its counterpart, instead of being potentially reactive.
Potassium iodide can be converted to molecular iodine in your body, which requires peroxidase enzymes. Peroxidase enzymes are like carpenters that require energy and metabolic resources. In comparison, it requires no such metabolic expense to convert molecular iodine to potassium iodide, which is how extra iodine is removed from your body.
Molecular iodine forms relationships with other molecules by accepting electrons. It can bind to toxic substances, helping to remove them from your body. It can also bind to potassium iodide, forming I3-. More I2 molecules can be attached, in turn reacting with other molecules in a bewildering array of possibilities. These relationships include a wide range of cellular and gene components, as well as many nutrients. Importantly, molecular iodine is a vital nutrient for the proper function of your genes, expanding its role well beyond thyroid hormones.
Molecular iodine and potassium iodide are inorganic forms of iodine, because the molecules lack carbon. When iodine combines with a carbon-containing molecule (a molecule synthesized in a biological system), it is called organic iodine. Iodine in humans readily combines with carbon-containing amino acids or fatty acids, forming organic iodine compounds. One example of an organic iodine compound is thyroid hormone, wherein iodine is bound to the amino acid tyrosine. Iodine also binds to the amino acid histidine, which helps move iodine around your body on histidine-rich transport proteins that are commonly present in your blood. It can also combine with histidine-rich antioxidants like carnosine, which protects your brain, heart, and muscles. It can bind to milk proteins in breast tissue. When iodine is bonded to a protein it is called an iodinated protein.
New scientific tools enable us to see that iodine is used in every cell of your body, in many different ways. The main point to understand is that molecular iodine is a mover and a shaker, the life of the party.
Oxygenation of Earth
The atmospheric oxygen of Earth is required for human life. Plants produce oxygen in the process of photosynthesis, using energy from the sun to convert carbon dioxide and water into carbohydrates and oxygen. But how did this get started in the first place? How did life forms evolve to be in harmony with oxygen? As it turns out, iodine is a major player in the oxygen evolution game.
Planet Earth is approximately 4.5 billion years old. Rock and fossil records prove that Earth had a significant oxygen-containing atmosphere 2.45 billion years ago. It is likely that bacteria used photosynthesis to start producing oxygen in larger amounts as far back as 3.5 billion years ago, and for almost a billion years the oxygen reacted with volcanic gases, various minerals, and large amounts of iron in the atmosphere. Not until these highly reactive substances were oxidized did oxygen fill the atmosphere.
The first forms of life on Earth were very simple, single-cell bacteria that did not have a nucleus. These first cells lived in a no-oxygen environment. They evolved into bacteria that used photosynthesis to make oxygen. The most primitive cell type in this category is blue-green algae (cyanobacteria). Even though seawater contains only small amounts of iodine (0.05 parts per million), blue-green algae has a penchant for accumulating iodine. Blue-green algae and its evolutionary children are the primary sources of oxygen for Earth’s atmosphere, continuing to play a vital role in the biosphere up to the current day. The primary cells that have oxygenated Earth have 3.5 billion years of genetic experience with iodine on board. It would be foolish to think that iodine is not crucial to any living cell that depends on high levels of oxygen metabolism, including human cells.
Blue-green algae eventually evolved into multicellular structures such as kelp. Kelp is brown-algae large seaweed. Its cells have a nucleus and other cellular compartments, making them more advanced than simple, single-cell blue-green algae. Kelp is the most effective accumulator of iodine of any life form, yet it was not until 2008 that iodine metabolism within kelp was better understood, including its specific antioxidant function.
In a non-stressed state, kelp accumulates iodine in the form of potassium iodide and concentrates it in the cell wall (not inside the cell). The potassium iodide does not form chemical bonds within the cell wall; rather, it is held in place via its ion charge, which forms harmonious associations with carbohydrates, polyphenols, or proteins that make up the cell wall. This is interesting because iodide ions can easily become reactive, yet primitive algae figured out how to keep them in a useful “at rest” condition. This is like keeping soldiers with their feet up in the barracks, waiting for a call to arms.
Iodine as an Antioxidant
When kelp comes into contact with a stressor, then iodide swings into action as the front line of defense. One of its antioxidant functions is to neutralize ozone. It does this by producing large amounts of molecular iodine that are then released into the air, forming small particles of iodine oxides, in turn helping cloud formation. This is a fascinating link between a biological antioxidant system and weather. It is also interesting that humans living along seaweed-rich coastal areas inhale molecular iodine in nutritionally relevant amounts, an important aspect of human evolution.
Researchers have exposed kelp to the signs of a bacterial germ gang (biofilm), indicating to the algae that it is about to come under infectious attack. In response, the kelp releases large amounts of hydrogen peroxide (H2O2) from its outer cell wall, along with potassium iodide. This large germ-killing oxidative burst, like firing a shotgun at the bacteria, peaks within thirty minutes and returns to baseline three hours later. Iodine is essential for regulating the assault, helping to kill the germs while controlling the oxidation process (preventing the gun from backfiring).
These researchers point out that the unique chemistry of iodine enables it, as an antioxidant, to neutralize a variety of free radical reactions that can occur when it deals with hydrogen peroxide, ozone, hydroxyl radicals, and superoxide. This makes iodine a very versatile antioxidant. It is highly likely, since humans process large amounts of hydrogen peroxide and oxygen while making energy, that the evolutionary antioxidant lessons of iodine help us with superior energy production within our cells.
Scientists now estimate that molecular iodine has fifty times the antioxidant power of potassium iodide and ten times the activity of vitamin C. While the precise mechanisms of the antioxidant activity of different forms of iodine remain to be elucidated, there is no question that iodine, especially molecular iodine, is a potent antioxidant.
Iodine as an Energy-sparing Nutrient
Living cells are always looking for the most energy-efficient way to handle a task or problem, one more example of my theme of efficiency. There are numerous organic antioxidants, including vitamin C, isoprenoids, polyphenols, and glutathione. These are metabolically and energetically expensive to make.
In the case of kelp, these organic antioxidants are used by the inside of kelp cells to sustain life, whereas iodide is concentrated in the cell wall. These organic antioxidants would be capable of interacting with any stressful oxygen situation, but in doing so they could be depleted too rapidly, in turn compromising survival. Experiments show that these organic antioxidants are not used to combat the stressful encounters of kelp with the environment.
Rather, inorganic iodide is used. Inorganic iodine requires no energy to produce and is available from seawater. Thus, the ability to use it as a front-line defense is an energy-sparing survival strategy that kelp developed.
The researchers went on to show that iodine is nontoxic to human white blood cells of the immune system, and that it helps control the oxidative burst of germ-killing neutrophils. This means that human front-line immune troops, evolving from ancient systems of protection, have learned to use iodine in manners similar to evolutionary principles of kelp. It is likely that human immune cells have learned to use iodine in even more sophisticated ways than kelp does, especially for front-line immunity.
Algae use a peroxidase enzyme to convert the reactive potassium iodide into the friendlier molecular iodine, which can then diffuse into the cell. From a cell’s point of view, potassium iodide is a bit of a hot potato, better kept at arm’s length and used for aggressive defense purposes. It is like having an ornery watchdog on patrol in the yard, one that is not suitable to be in the house with the kids. The kids like a friendlier pet, molecular iodine.
It stands to reason that if iodine is lacking for cellular nutrition, then other organic antioxidants will be called upon and used up faster. A study back in 1984 showed that T4 and rT3 give up their iodine to stop free radicals coming from rancid lipids. This means that the iodine in thyroid hormones could be diverted for antioxidant purposes instead of for thyroid hormone, a backup system for helping the body cope with rising levels of free radical damage. It makes sense that an optimal intake of iodine for cellular nutrition would be a foundation for the entire antioxidant team, sparing organic antioxidants for more advanced antioxidant chores.
It is likely that the harder cells must work or the faster they metabolize (meaning more oxygen is used), the higher the need for iodine as basic protection. Before iodine was discovered, there were many theories about what caused goiter. The Germans had the theory that goiter could be triggered by hard work, an observation that occurred because their hard-working people were often borderline iodine deficient. This observation is consistent with the idea that the need for iodine within cells increases as cells work harder.
Free radical damage increases as health declines or as part of the typical process of aging. General signs of wear and tear, increased demands of stress, any poor health condition, and the condition of being overweight all imply that antioxidants are being used up faster and may be lacking. If iodine follows its evolutionary pattern, it could well be an antioxidant of first resort, since inorganic iodine is metabolically inexpensive for your body to use in an effective antioxidant role.
The modern research shows that iodine is involved in the most fundamental processes of life: helping to guide the safe use of oxygen, as well as enabling the oxygenation of Earth’s atmosphere; even influencing cloud formation and weather. Humans have the most advanced cellular system of iodine-utilization known. While there are many actions of iodine in cellular metabolism, it is now clear that contributing to the antioxidant team is one of them. Indeed, the ability to use iodine in cells significantly improves the capability for energy production and is a defining feature of superior human-survival advantage.
Iodine and the Evolution of Intelligence
Modern iodine knowledge provides thought-provoking insights on the evolution of human intelligence. A devastating problem occurs in the womb during nervous system development if iodine is lacking. Serious deficiency results in irreparable brain damage called cretinism. Less serious deficiency lowers IQ, reducing human potential.
Iodine in the fetus is taken up by the choroid plexus, a core brain structure required for brain formation. We do know that the need for iodine at this crucial time of brain development exists not to increase the rate of thyroid metabolism in the developing fetus. To the contrary, the placenta is loaded with deiodinase enzymes that prevent excess metabolic activity of thyroid hormones. This guards the fetus against surges of thyroid hormone that could be coming from the mother. While small amounts of thyroid hormone are needed for the first three months of neurological development, those levels are indeed small.
Although the details are not clear, it appears that iodine provides antioxidant protection and/or crucial cell regulation for nervous system development. The fetus’s thyroid gland is formed by week eleven or twelve and begins to secrete hormones at week sixteen. Fetal thyroid hormones are then augmented with the mother’s supply of thyroid hormones in order to obtain full-term growth. These higher levels of thyroid hormones are occurring from week sixteen onward. And, of course, this higher metabolic level of thyroid hormones requires iodine.
It is truly unfortunate that severe iodine deficiency in many poor areas of the world continues to result in the condition of cretinism (severely stunted physical and mental growth, and major handicaps). Still, five million people suffer from cretinism.
While cretinism marks the far end of the iodine-deficiency spectrum during pregnancy, varying degrees of a lack of iodine during fetal development result in reduced IQ. Thirty percent of the world’s population is at risk for significant iodine deficiency. A lack of iodine during fetal development can also cause poor development of the thyroid gland, contributing to poor thyroid function in later life. Some of these thyroid problems can be managed with nutrition, and medication when needed. However, it is difficult to correct the brain structures that did not form in an optimal way in the womb. There is an important window of opportunity for iodine to work its magic. If that opportunity is missed, it cannot be corrected at a later time simply by taking iodine.
Americans have been lulled into thinking that this is a problem of developing countries; far from it. While cretinism in America is rare, a lack of iodine is associated with the obesity epidemic, the epidemic of prematurely born babies, miscarriages, and with too many children born with reduced potential for optimal intelligence.
A Major Iodine Discovery Rewrites History
In 1996 an advanced system of iodine uptake into the thyroid gland, as well as into other key body areas such as the choroid plexus and digestive system, was discovered. It is called the sodium-iodine symporter (NIS). NIS enables top-priority areas of your body to grab iodine from the circulation before other, less important areas can get it. This is an evolutionary first-dibs system, since iodine has often been scarce during our evolutionary development.
The importance of NIS was immediately obvious to evolutionary researchers, and in 1998 exhaustive research was published documenting the identical skeletal nature of Neanderthals and modern-day cretin humans. The theory was persuasively put forth that a singular genetic advancement resulted in an advanced NIS system in Homo sapiens. This enabled the development of a superior thyroid gland, which led to the evolution of higher intelligence, allowing modern humans to take their place above Neanderthals.
In addition to being active in the digestive system, brain, and thyroid gland, NIS is also known to be active in the male reproductive system (testes and prostate), female reproductive system (ovaries, endometrial glands, and placenta), lactating mammary glands, skin (another defense barrier), pancreas (blood sugar metabolism), bronchial airway, lungs, thymus gland (immunity), salivary glands, lacrimal glands (eyes), bladder, gallbladder, and kidneys. It is likely that other tissues expressing NIS will be identified as time moves along, especially as techniques for identifying NIS activity improve.
All we know for sure is that when NIS is activated in any one of these body tissues, it wants iodine, once again demonstrating a diverse need for iodine. Based on the emerging picture of iodine as a nutrient fundamental to cellular processes, it may well be that symptoms of poor function relating to any of these body tissues may be caused, at least in part, by a deficiency of iodine. Skin problems and female complaints are typical symptoms of hypothyroid, and it may well be that iodine deficiency is causing them to become manifest.
It is clear from the NIS-expressing tissues thus far identified that a primary role of iodine is to protect any surface of the body which comes into contact with the outside world, including skin and mucosal linings of digestion, the urinary tract, eyes, female reproductive system, and breathing. It is noteworthy that the majority of hypothyroid symptoms could manifest entirely as a result of iodine deficiency, as distinct from a deficiency of thyroid hormones. This means that restoring the intake of iodine to an optimal level could go a long way toward clearing up symptoms which may otherwise appear to be hypothyroid symptoms.
Competition for Iodine
Your body is very good at using nutrients for multiple duties. This sets up a situation of competition for the nutrients within your body. For example, NIS is active in many tissues, taking up iodine to help your eyes, sinuses, mouth, respiratory system, skin, digestive tract, and reproductive system. These areas of need will compete with your thyroid gland and brain for iodine.
Even if all these areas are doing pretty well, they all still require some iodine for baseline needs. However, if one or more of these areas is struggling, then the need for iodine rises. This type of issue is not taken into account by government officials when setting guidelines for iodine intake.
Once you drop below an optimal level of intake for a nutrient, then your body is forced into a juggling act, trying to distribute what little you have to multiple areas of need. In other words, not only do you need to water the lawn, you also need to water the flowers, shrubs, and trees. This is never a desirable state of affairs if you are short on water. In the case of iodine, this type of problem has typically been going on for years before a medically diagnosable thyroid problem finally raises its hand.
Complicating matters is that stressed thyroid glands often have weakened structure, resulting in a “leaky” problem. This means that iodine entering the gland can leak out inappropriately, and therefore higher iodine intake is needed.
If you are struggling with thyroid symptoms and any type of health issue relating to your brain, eyes, sinuses, mouth, respiratory system, skin, digestive tract, or reproductive system, then you are likely to benefit from a higher intake of iodine.
Potassium Iodide
We know a fair amount about how potassium iodide is absorbed and transported in your body, as a result of the common use of radioactive iodides in medical imaging and thyroid cancer treatment.
One role of NIS is to absorb iodides from the small intestine into your bloodstream. Over ninety percent of iodides that reach the small intestine are absorbed, indicating the high priority placed on getting this nutrient into your body.
The thyroid gland has the strongest NIS system, meaning it will take up iodides from your bloodstream better than any other organ system. TSH (thyroid stimulating hormone) acting on NIS turns up the NIS volume knob on your thyroid gland, ensuring that the thyroid gland gets the iodine it needs. Other body tissues that use NIS to absorb iodine do not respond to TSH, because during evolution they were created before the thyroid gland and have no TSH receptors.
As iodide enters your circulation, it goes into solution with blood plasma and is taken up by red blood cells. Iodide easily goes in and out of red blood cells. Within ten minutes the red blood cells transport iodide to the fluid surrounding cells throughout your body. It does not enter most cells in the iodide form. The rapid accumulation of iodides in the red blood cells, blood plasma, and extracellular tissue spaces forms an iodide pool, a dynamic reservoir of this important nutrient.
What is not used by your body tissues then travels back into the circulation and is processed by your kidneys. About thirty percent of iodides are filtered into the urine and excreted, even if iodine is lacking. High doses of iodide are quickly excreted by the kidneys. Radioactive iodide rapidly accumulates in the kidneys following ingestion, because the kidneys are trying to filter excess iodides out of the body. Within several hours, the higher levels of radioactive iodide are removed by the kidneys, returning kidney iodide levels to a baseline amount. Ninety percent of the removal of iodine from the body is due to ongoing kidney clearance of iodides.
A number of important insights can be deduced from these findings. The fact that iodides are rapidly spread to the fluids between cells all around the body speaks to the importance of iodine, independent of thyroid hormone, for your body as a whole. There is absolutely no way your body would quickly transport a substance almost everywhere unless there was a potential need.
We know that immune cells which are fighting infection can use iodide to make weapons to kill germs. It makes sense that this system of iodide distribution would be an effective way to keep the ammunition supply lines functional. A deficiency of iodide would impair optimal immune function, especially during times of battle.
Iodides can be converted to molecular iodine. This enables cells to uptake this friendlier form of iodine for internal cellular use. Molecular iodine diffuses into cells and does not use NIS. Only iodides use NIS. It stands to reason that ingested iodides are rapidly deployed so that if cells need iodine, they will be able to convert iodides to help out. Iodides may not be the preferred form of iodine for internal cell use, but they are a common nutritional form, one that has been around since life evolved, and cells have learned to use them for survival advantage.
Any extra iodides that aren’t used rapidly head to the kidneys, with a continual percentage of them being flushed out. While iodides have nutritional value, they are also the preferred “waste product” form of iodine. When iodide levels are high, they are cleared out rapidly. More normal amounts of iodide are continuously cleared out at a slower pace. Molecular iodine is converted to potassium iodide in order to be cleared out.
The fact that red blood cells rapidly take up and release iodide is also quite interesting, whereas T4 and T3 are not taken up by red blood cells. Red blood cells are the only cells in the human body that do not have mitochondria, meaning they do not make energy by oxygen-combustion methods and do not have advanced repair mechanisms. This is why red blood cells are replaced every four to six weeks; they get worn out doing what they are doing and have no way to fix themselves. Red blood cells don’t need to worry about having iodides inside, since key cell components for advanced oxygen-based energy production do not exist in them and therefore cannot be damaged by iodides.
Red blood cells also carry iron in their hemoglobin. Iron is vital for health and is needed for cellular T3 activity. However, iron is potentially far more reactive than iodides in terms of generating free radicals. Iron is a true double-edged sword. Having iodides on board red blood cells would actually help protect against any iron that was inappropriately leaking out of red blood cells during the transport process. One of the great evolutionary purposes of iodides was to reduce the oxidizing power of iron in Earth’s early atmosphere. It is quite likely that red blood cells have learned to use iodides to help manage iron issues which would otherwise be stressful.
The Extreme Importance of Molecular Iodine
In comparison to radioactive iodides, there is far less research on molecular iodine. The first efforts in this regard occurred under the funding of NASA in the 1990s, when they were considering using molecular iodine to purify drinking water on space flights. While some molecular iodine is converted to potassium iodide under the influence of hydrochloric acid in the stomach, not all of it is. This was the first research to prove that much of ingested molecular iodine was absorbed as molecular iodine by diffusing across the digestive lining and into the blood. Once in the blood, molecular iodine readily interacts with blood components, forming useful relationships with proteins, fatty acids, and cholesterol, much more than do iodides. Molecular iodine is not taken up by red blood cells. It easily catches a ride on other compounds in the bloodstream and hops off when desired. This research showed that in healthy young men, several weeks of very high iodine intake (up to 70 mg per day) caused no statistically significant changes in T3, T4, or TSH. The intake of molecular iodine was cleared within eleven days following the end of the study, captured as potassium iodide in urine. This study proved molecular iodine is eventually converted to potassium iodide for removal from the body.
A research group from Mexico has done the most to understand the differences between molecular iodine and potassium iodide for cellular and breast health. They have shown in animal and cell studies that iodide is converted to molecular iodine, in turn forming iodolactones. These iodolactones occur when molecular iodine bonds to long-chain unsaturated fatty acids, such as arachidonic acid (AA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA). EPA and DHA are known as essential fatty acids and are quite popular as dietary supplements for cardiovascular, metabolic, eye, and brain health. Iodolactones reside in the outer cell membranes as well as in the membranes of various cellular components. Of immense importance is that iodolactones regulate gene signals of the cell and are intimately involved with growth factors and the cell signaling. These are the very same gene signals that are involved with keeping cells healthy and not making too many half-dead cells.
The Mexican researchers have shown that molecular iodine reverses abnormal tissue and cystic changes in breast tissue, whereas iodide does not. They have proven that molecular iodine is taken up rapidly by cells, within five to fifteen minutes after intake, whereas iodide is not. Molecular iodine uptake is dependent on cellular protein metabolism (gene activity) but not on cellular energy production. Uptake into cells is by diffusion and not by NIS.
Recently, these researchers issued a paper explaining the safety of molecular iodine in higher doses and its highly protective benefits for the thyroid gland, breast tissue, prostate, brain, and digestive system. They are specifically calling for a change to international public-health proclamations for iodine, recommending at least 3 mg of molecular iodine per day for individuals with health concerns that are highly benefited by molecular iodine.
How Much Iodine Is Safe?
The question of the safety of high-dose iodine depends on a number of variables, including the form of iodine ingested, adequacy of related nutrients, and health of the individual. People in better health are likely to tolerate very large amounts of iodine quite well, whereas for those in poorer health some issues may arise. Because it is those in poorer health who are most likely to try high-dose iodine as a remedy for their problems, a better understanding of the risks and benefits should guide potential use.
In healthy individuals with no history of medically defined thyroid problems, iodine in any form appears to be well tolerated up to 30 mg per day. With higher doses, mostly as potassium iodide, there is an inhibitory effect on the release of T4 and T3 from the thyroid gland. Doses up to 300 mg of potassium iodide per day have been tested in healthy men, with only slight changes in thyroid hormone levels occurring; these levels revert to normal two weeks following the removal of iodine intake. Iodides in high doses may slightly interfere with the release of thyroid hormone in healthy people.
It appears that a minimum of 3 mg of molecular iodine per day is needed to support health issues involving the prostate or breasts; with 6 mg of molecular iodine per day being more beneficial than 3 mg. Doses below that level do not appear helpful. No side effects to the levels of thyroid hormones have been observed at these levels of intake.
Dosing of 9 to 12 mg of molecular iodine per day showed similar benefits but also some side effects, including interference with the release of thyroid hormones in twenty percent of patients. Side effects disappeared when iodine was discontinued.
The human studies on potassium iodide and molecular iodine do not explore the simultaneous use of synergistic nutrients that are needed for proper iodine metabolism. Thus, iodine as a singular supplement in healthy people is quite safe for most in doses up to 30 mg per day, especially in the form of molecular iodine. It is obvious that the use of synergistic nutrients will enhance iodine utilization, but no studies on this subject have been conducted.
In individuals with existing problems of the thyroid gland, the use of iodine is more complex. On the one hand, deficiency of iodine and other nutrients in the first place underlies the development of most problems within the thyroid gland. However, now that problems exist, it is like having a sprained thyroid gland. In general, this means taking lower doses of iodine along with comprehensive nutritional support to build up fitness of the thyroid gland. Slowly, over time, the dose of iodine can be increased. It is similar to conditioning yourself to jog five miles a day when, at your starting level of fitness, you have trouble jogging six blocks.
Virtually any study warning against higher iodine intake is based on populations of people with endemic thyroid problems, including a deficiency of iodine as well as many other needed nutrients. That is not a relevant patient population on which affluent Western countries should base iodine recommendations. That said, any person with a medical history of thyroid problems has evidence of a sprained thyroid. In this situation, the primary fuel for the production of thyroid hormones may not work well in high doses, due to the inherent limitations of the struggling gland. The short- and long-term goal is not to avoid iodine but to get it to work in a healthy way within the thyroid gland, starting with smaller amounts.
Iodine supplementation will always work best as part of a comprehensive nutrient-support program. When in doubt, proceed slowly and build your health gradually. There is tremendous potential for health improvement with higher intake of iodine.
Covering Your Iodine Basic Needs
When it comes to iodine, the Institute of Medicine’s Food and Nutrition Board recommends 150 micrograms (mcg) of iodine for adults, 290 mcg for lactating women. This is often enough to prevent the blatant malfunction of thyroid hormones that can result in goiter, cretinism, or other thyroid pathology. It is enough for the thyroid gland to limp along, while apparently leaving some dog-bone scraps for other iodine needs in your body.
These U.S. officials think the safe upper limit for iodine is 1 mg per day (1000 mcg), a guideline rooted in public-health paranoia and denial of iodine science. There isn’t even a passing thought given to the quality of the iodine consumed, thus, encouraging people to consume iodized salt to cover their iodine needs.
Interestingly, millions of Japanese safely consume up to 5 mg of iodine per day from a variety of fresh seaweed sources, thirty-three times the official U.S. government guidelines and far higher than their arbitrary “safe upper limit.” Fresh seaweed contains several forms of iodine, including potassium iodide, molecular iodine, and iodate (iodine attached to three oxygen atoms - IO3
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