Iodine: Overview
What is iodine?
Iodine (I) is an essential nonmetal trace element.
It is part of the “halogen” group of elements (Group 17 of the periodic table), which includes fluorine (F), chlorine (CL), bromine (Br), iodine (I), and astatine (At). These elements are rarely found in their free elemental forms in nature due to their reactivity. Instead, they combine with other elements to form compounds. They are electronegative, meaning they have a tendency to attract electrons to themselves within a covalent bond.
Out of these elements, iodine is the least reactive, and is the least abundant nonmetal element in nature. Iodine occurs in different forms. It’s elemental form is a diatomic molecule (I2); a molecule composed of two atoms. It’s other forms include iodide, and compounds such as iodides and iodates, also known as iodide salts. Iodide is an ion of iodine and is monoatomic, or composed of one atom.
An ion is an atom or group of atoms that are positively (cation) or negatively (anion) charged. An iodine ion is negatively charged and is written as I‒. The form of iodine plays a role in how it is absorbed and used by the human body.
Iodine is not only found in the human body, but is also found, primarily in the form of iodide salts, in trace amounts in sea water, fresh water (lakes, rivers, streams, rain, and groundwater), rocks, soil, plants, and animals. This relatively rare element serves many important functions in our planet, and our health.
How is iodine used by the body?
In the human body, the highest concentration of iodine is found in the thyroid gland. The thyroid gland is a small butterfly shaped organ found at the base of the neck that is responsible for the synthesis and release of thyroid hormones. To produce these thyroid hormones, iodine is needed.
Thyroid hormones are released into the bloodstream where they travel to cells throughout the body. They are involved in a number of functions, including the regulation of the brain and nervous system, maintenance of bones, and control of metabolic rate (how quickly nutrients are broken down into energy), respiration rate, and heart rate. They also play a role in menstrual cycles and muscle control.
The process of metabolism produces heat, which in turn influences the body’s temperature. Thyroid hormones also help regulate body temperature by boosting the activity of brown fat, a type of adipose or fat tissue that specializes in producing heat, and by regulating sweat.
Thyroid hormones are involved in key metabolic reactions such as protein synthesis and enzyme activity (1).
While iodine is more commonly known for its role in the thyroid, it is found throughout the body in small amounts, including in the mammary glands, salivary glands, choroid plexus in the brain (cells that produce cerebrospinal fluid), gastric mucosa (a mucous membrane that lines the inner surface of the stomach), ovaries, uterus, ciliary body of the eye, lacrimal gland, skin, kidneys, liver, lung, spleen, adipose tissue, bones, muscles, prostate, pancreas, and thymus (an organ that plays an important role in immune response that is part of the lymphatic and endocrine systems).
During pregnancy, a much higher concentration of iodine is found in the mammary glands since iodine is crucial for bone, brain and nervous system development in fetuses and infants.
Tissues such as the thyroid, mammary glands, salivary glands, gastric mucosa and ovaries contain sodium iodide symporter (NIS), a transport protein responsible for the uptake of iodine in the form of iodide into cells and tissue. In the absence of NIS, it is transported into cells by passive diffusion, though the effectiveness is dependent on other factors.
The exact role iodine plays in these tissues is not fully understood. The interconnected nature of the human body and the use of the term iodine to refer to multiple forms makes it difficult to separate the functions of free iodine from its other forms, such as in the case of thyroid hormones.
However, studies show that iodine acts as a key part in protecting cells against viruses, bacteria, and oxidative damage. It is believed to be able to do this through cell wall penetration and oxidation. In certain amino acids and fatty acids, it disrupts the cell’s structure and inhibits its ability to synthesize proteins.
In a type of oxidation, iodine (I-) may act as an electron donor that quenches free radicals (2). This protects the cells from oxidative damage.
Halogens such as chlorine, fluoride and bromine can become toxic to the body in high amounts. They compete for NIS. When iodine levels are in sufficient amounts, they can crowd out the other halogens and prevent them from being absorbed. In this way, iodine helps detoxify the body from unwanted toxins.
Iodine also exhibits antiproliferative, proapoptotic, and pro differentiating effects. Antiproliferative refers to the suppression or inhibition of cell growth. Apoptosis is a form of programmed cell death that is necessary in eliminating unwanted or unhealthy cells; and cell differentiation is the process in which cells mature and become more specialized. In diseases such as cancer, differentiated cells tend to be less aggressive and spread more slowly than undifferentiated cells.
All of these effects of iodine play a role in maintaining the proper function of organs and preventing the growth of cancer and malignant cells. Iodine has been used in the prevention and treatment of a number of cancers, including breast and prostate cancers.
The role of iodine and thyroid hormones in proliferation and apoptosis regulation affects cell regeneration as well, such as in the case of hair, skin, and nails.
Iodine is also needed for the assimilation of other nutrients, and the proper assimilation and use of iodine by the body is dependent on other minerals and trace elements. There is an interdependent relationship between iodine and nutrients such as iron, selenium, zinc, silica, magnesium and calcium.
These are only some of the many roles that iodine plays in the body. The exact functions and mechanisms in which iodine works is still not fully understood.
After circulation, iodine is mainly excreted from the body through urine via the kidneys.
What happens if we don’t get enough iodine?
Iodine deficiency is one of the leading preventable causes of infant intellectual disability (previously known as mental retardation) around the world. Iodine is critical for proper development of the brain and nervous system, and iodine deficiency during pregnancy can lead to brain damage, stunted growth, and delayed sexual development in the child.
In individuals of all ages, without the necessary iodine, the thyroid must work harder to produce thyroid hormones, resulting in goiter, or an enlarged thyroid, and conditions such as hypothyroidism. The metabolism slows down and the body is unable to produce as much energy. This may result in unexpected weight gain, as well as fatigue and weakness.
Other symptoms of iodine deficiency include muscle and joint pain, slow heart rate, brain fog, puffy face, hair loss, dry skin, poor memory and learning, restlessness, fearfulness, increased cholesterol, lowered immunity, and heavy or irregular periods and infertility in females.
Research shows potential links between iodine deficiency and the development of cancer due to oxidative stress.
What causes iodine deficiency?
It was once believed that iodine deficiency was rare in North America due to iodine being added to salt and bread. However, poorly executed and reported studies, such as the Wolff-Chaikoff study in 1948, resulted in increased fear surrounding iodine and the potential dangers of getting too much. Iodine in bread was replaced with the toxic substance bromine, and iodized salt became less common.
The excess of any substance can be detrimental to the human body. All aspects must work together in balance for proper function. Nevertheless, the drastic response to the fear of too much iodine resulted in less availability of iodine, and an increased rate of iodine deficiency, and its related complications.
According to the World Health Organization, approximately 2 billion people suffer from iodine deficiency. This would suggest that the recommended daily intake (RDI) may not be sufficient for many people, since iodine levels depend on a variety of factors.
Iodine depleted soils, stress, and the increased exposure to pollution, radiation, pathogens, bacteria, etc., all influence our iodine levels.
Even if iodized salt is available, it is generally produced using refined table salt. This type of salt is not the same as sea salt or Himalayan salt, and may include harmful additives. Too much sodium in any form of salt also poses a health risk.
Negatively charged ions such as halogens bromine, fluorine, and chlorine can compete for NIS and can prevent iodine from being absorbed if there are insufficient amounts. Chlorine is often added to drinking water, bromine is added to processed baked goods as an additive, and fluorine is often added to toothpaste. These substances can also be found in household cleaning products, pesticides, and more. The increased exposure can lead to an increased risk of iodine deficiency.
Seafood such as seaweed and saltwater fish are rich in iodine, but it can be difficult finding a pure source that isn’t contaminated by mercury, arsenic, and radiation.
The low availability of iodine and the increased exposure to pollutants and stress has made iodine deficiency a common problem.
Iodine supplementation
With the prevalence of iodine deficiency and the threat it poses to our health, iodine deficiency has become a global health concern. The lack of iodine rich sources of food has made supplements a viable option in getting what we need.
There are different forms of iodine supplements. Potassium iodide (iodide bound to potassium) or sodium iodide (iodide bound to sodium) are common sources for tablets and liquid solutions. This is due to the fact that iodide ions are generally not found in free form, but bound to other atoms or elements. Some supplements such as Lugol’s iodine consists of a mixture of potassium iodide, elemental iodine, and distilled water.
Other forms of iodine, such as potassium iodide and povidone-iodine solutions are used for different purposes. Potassium iodide is used to help protect the cells against radioactive iodine while povidone-iodine is applied topically (on the skin) to treat wounds.
What is nascent iodine?
Nascent iodine refers to a monatomic, free form of iodine, or a single atom of iodide (I-) that is unbound to any other atom or element, and holds a negative electromagnetic charge. It is produced by subjecting the iodine to an electromagnetic field or other form of energy and then suspending it in a solution.
Why nascent iodine?
Nascent iodine is in the form of iodide (I–) and is more readily absorbed by the body.
The body absorbs diatomic or molecular iodine (I2) and monatomic iodine or iodide (I–) differently.
Elemental molecular iodine (I2) does not occur in nature, but can be obtained through commercially-made mixtures made from iodide and iodate salts. When this mixture is exposed to the low pH of the stomach, they react, and iodine is taken up as in the form of molecular iodine through facilitated diffusion.
Dietary iodine in the form of I– is obtained when iodate and iodide salts are broken down in digestion. Iodide is absorbed in the gastric mucosa (stomach lining) via the transport protein NIS and concentrates in NIS-rich tissues.
I2 and I– have been believed to have different therapeutic effects.
Molecular iodine is believed to avoid thyroid uptake and, as such, may help in pushing the effects of iodine in other parts of the body. This would make it more effective in treating certain conditions.
However, iodine is only found in nature in the form of iodide, and iodide salts as well as molecular iodine are all readily broken down into iodide in the body to be used. The body is able to oxidize iodide to iodine in the process of organification.
It is unclear how much of the molecular iodine gets broken down into I– and how much remains in the form of I2.
The studies used to support the use of molecular iodine (I2) over iodide (I–) may not take into consideration the presence of other substances or the form of iodide used. Some substances may interfere or inhibit NIS, which is needed for adequate iodide uptake. If iodide levels are high enough, they may be taken up without the use of NIS. In the absence of NIS, I2 is absorbed more readily than iodide.
Different forms of iodide, such as whether it is protein bound or is used with other ingredients such as fillers, binding agents, excipients, or preservatives, may also be less effective or pose a greater risk of allergic reactions.
Nascent iodine is made without many of these other ingredients. The monatomic form of iodine (I–) is suspended in a solution that, in the case of Global Healing’s Detoxadine, is made of distilled water and vegetable glycerin (glycerol) without any impurities. This form of iodine is more readily absorbed since it is already in the form that the body uses.
Molecular iodine or iodide salts require the body to break it down. Depending on the strength of the bond, it may result in less iodine being absorbed or used by the thyroid.
The bioavailability of nascent iodine makes it a more preferred choice of supplement.
It is important to note that selenium deficiency may occur at the same time as iodine deficiency, and may cause reactions to iodine supplements. In the case where both deficiency of selenium and iodine occur, it is recommended to supplement both of them at the same time.
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