The Content Of Iodine In Food: Effects On The Body, Symptoms Of Deficiency And Excess

Useful properties of iodine and its effect on the body

Did you know that iodine deficiency is currently considered by the World Health Organization (WHO) as the most common and easily preventable case of impaired cognitive development in children in the world? There are at least 30 million people suffering from this preventable disease.

Iodine is a trace element and an important component of the thyroid hormones triiodothyronine (T3) and thyroxine (T4). These hormones regulate the metabolic activity of most cells and play a vital role in the early growth and development of most organs, especially the brain. Insufficient consumption of iodine-rich foods can lead to insufficient production of these hormones, which negatively affects the muscles, heart, liver, kidneys, and developing brain.

https://www.who.int/nutrition/topics/idd/en/

The iodine deficiency statistics speak for themselves:

• The National Medical Nutrition Survey found that iodine levels have dropped by 50 percent over the past 30 years.

• More than 96 percent of the more than 5,000 patients examined were iodine deficient in a clinical study conducted by thyroid expert Dr. David Brownstein.

• According to WHO, iodine deficiency affects 72% of the world's population.

• In 2011, 70 percent of households worldwide had access to iodized salt.

  https://www.who.int/bulletin/volumes/94/2/15-160036/en/

   

Iodine as a chemical element was discovered in France by Bernard Courtois at the beginning of the 19th century. In Mendeleev's periodic system, it is denoted by the letter "I" and assigned atomic number 53. In its pure form, under normal conditions, iodine is represented by crystals with a color from dark gray to blue. It is poorly soluble in water, organic solvents are used for its solutions, in which iodine acquires a rich brown or purple color. Not surprisingly, the very name "iodine" in Greek means purple or violet. Iodine is not found in the form of isolated deposits in nature, but it is distributed everywhere in small quantities. For the extraction of iodine, its compounds, salts rich in iodine are used, from where it is isolated chemically. The human body is unable to synthesize iodine on its own.

Iodine is a truly essential micronutrient in our diet and plays an important role in normal growth and development. Unfortunately, iodine deficiency is a major public health problem worldwide. It affects 2 billion people worldwide and its prevalence is increasing, especially among teenage girls and pregnant women.

https://pubmed.ncbi.nlm.nih.gov/18053280/

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3119440/, https://pubmed.ncbi.nlm.nih.gov/18053280/

The intake of dietary iodine is simply necessary for the production of thyroid hormone. Consequences of iodine deficiency include:

• goiter;

• intellectual impairment;

• growth retardation;

• neonatal hypothyroidism;

• and increased risks of miscarriage and infant mortality.

In 1990, the World Meeting of the United Nations set the goal of eliminating iodine deficiency worldwide. Significant progress has been made since then, largely due to universal salt iodization programs. Approximately 70% of all households worldwide now have access to iodized salt.

Therefore, despite significant progress over the past few decades, iodine deficiency remains a major health problem worldwide, affecting both industrialized and developing countries. Continuous monitoring of the iodine status of the population is still critical, and particular attention needs to be paid to monitoring vulnerable populations such as pregnant women and infants. There is also a need for constant monitoring of iodized salt and other sources of dietary iodine to prevent over-as well as under-nutrition of iodine.

Iodine is present throughout the body in almost every organ and tissue and is required by almost every system in the body to keep us alive and energetic. For this reason, iodine deficiency poses many health risks. That's why it's so important to regularly include iodine-rich foods in your diet.

Iodine is a truly essential mineral that is supplied to the body through iodine-rich foods, including certain salts (“iodized salt”), eggs, sea vegetables, fish, legumes, and other foods. It occurs naturally in mineral-rich soils as well as in ocean water.

The iodine found in foods and iodized salt contains several chemical forms of iodine, including sodium and potassium salts, inorganic iodine (I2), iodate, and iodide.

As we said, iodine is needed to create thyroxine (T4 hormone) and triiodothyronine (T3) are the two main hormones produced by the thyroid gland that control many important functions in the body.

1. Supports Thyroid Health

    

   The thyroid gland must have a high enough level of iodine to produce key hormones, including thyroxine. Thyroid hormones regulate many important biochemical reactions on a daily basis. Some of the most important include:

   • synthesis of amino acids from proteins,

   • activity of digestive enzymes,

   • proper development of the skeleton and central nervous system.

    

   When thyroid disorders such as hypothyroidism occur due to a low-iodine diet, symptoms can range from decreased metabolism to heart complications, changes in appetite and body temperature, changes in thirst and sweat levels, weight fluctuations, and mood changes.

   In addition, getting enough of this mineral is also important to prevent goiter or an enlarged thyroid gland.

    

2. May help prevent cancer

   Iodine is able to influence the increase in immunity and helps to induce apoptosis - the self-destruction of dangerous cancer cells. While it may help destroy mutated cancer cells, it does not destroy healthy cells in the process.

   For example, evidence suggests the ability of iodine-rich seaweed to inhibit the development of certain types of breast tumors. This is supported by the relatively low rates of breast cancer in parts of the world such as Japan, where women consume a diet high in seaweed.

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   Certain types of iodine therapy are also sometimes used to treat thyroid cancer.

    

3. Supports the growth and development of children.

   Iodine is especially important in the early stages of development, as fetal brain tissue and thyroid receptors are extremely dependent on this mineral for their normal formation.

   Research shows that iodine deficiency during pregnancy and infancy can interfere with healthy brain growth and development. Infants with iodine deficiency are more prone to mortality and are at high risk for neurodegenerative problems such as cretinism - low growth rate, motor problems and learning disabilities.

   Although doctors routinely test women during pregnancy for iodine deficiency, it is difficult to get accurate readings of iodine levels. As such, many health experts are now urging women to increase their intake of iodine-containing foods in their diet during pregnancy and supplement them with iodine when needed. Considering how common iodine deficiency is, this recommendation should really be taken seriously.

   Study: Iodine as Essential Nutrient during the First 1000 Days of Life, Iodine, Iodine metabolism and Iodine deficiency disorders revisited, Iodine supplementation for preventing iodine deficiency disorders in children

    

4. Supports Healthy Brain Function

   Research shows that iodine plays a role in healthy brain development and ongoing cognitive ability — which is why its deficiency is, according to experts, one of the most common preventable causes of mental disorders in the world, as well as neurodegenerative disorders.

   Study: The disorders induced by iodine deficiency, Iodine consumption and cognitive performance: Confirmation of adequate consumption

    

5. Keeps skin healthy and fights infections.

   One of the common signs of iodine deficiency is dry, rough and irritated skin that becomes flaky and inflamed. This mineral also helps regulate sweating, so people may experience changes in how much they sweat if their iodine levels become imbalanced.

    

   Another benefit is that iodine has the potential to help treat minor infections, such as those that form in scratches, as it has natural antibacterial properties.

    

6. Helps control sweating and body temperature.

   Sweating is an important detoxification method that the body uses to remove toxins. An iodine deficiency can disrupt this natural way that we remove waste from the body through the pores and control body temperature.

   Similar to the ability to produce enough sweat, a lack of iodine can also cause dry mouth due to abnormally low saliva production. This makes it difficult to enjoy food and can impair digestion to some extent.

   Study: Denis Wilson, md: Low Body Temperature as an Indicator for Poor Expression of Thyroid Hormone, Salivary Gland Function 5 Years After Radioactive Iodine Ablation in Patients with Differentiated Thyroid Cancer: Direct Comparison of Pre- and Postablation Scintigraphies and Their Relation to Xerostomia Symptoms

    

The norm of iodine per day

For people over 12 years of age, the recommended iodine requirement is 150 mcg per day.

For pregnant and lactating women, the recommended iodine requirement is 150-250 micrograms per day. This increase during pregnancy and breastfeeding should help increase the production of thyroid hormones in the fetus or baby, balance any potential losses from the mother, and supply the fetus with iodine so that it can produce its own thyroid hormones.

https://www.who.int/nutrition/publications/micronutrients/iodine_deficiency/9789241595827/en/

Foods high in iodine

Surely you are wondering how to increase your iodine level? The best way to maintain a normal iodine status is to eat foods high in iodine.

Other good sources of iodine include:

• seafood;

• dairy products (usually due to the use of iodine feed additives and iodoform disinfectants in the dairy industry);

• eggs.

The iodine content of vegetables and fruits varies depending on the iodine content of the soil, irrigation methods, and fertilizers used. The concentration of iodine in plants can vary from 10 µg/kg to 1 mg/kg dry weight. This variability affects the iodine content of animal products and meat, as it affects the iodine content of the foods that animals consume.

https://ods.od.nih.gov/factsheets/Iodine-HealthProfessional/#en5

Foods poor in iodine

Some thyroid disorders require an iodine-free diet. So you need to choose products that either do not contain this element at all, or contain it in minimal quantities.

Products that do not contain iodine:

Foods poor in iodine:

Symptoms, causes and consequences of iodine deficiency

Common signs of iodine deficiency include:

• Problems with salivation and proper digestion of food

• Swollen salivary glands and dry mouth

• Skin problems including dry skin

• Poor concentration and difficulty remembering information

• Muscle pain and weakness

• Increased risk of developing thyroid disease

• Increased risk of developing fibrosis and fibromyalgia

• Higher risk of developing problems in infants and children

Clinical signs and symptoms of iodine deficiency:

• Depression

• Difficulties with losing weight

• Dry skin

• Headache

• Lethargy or fatigue

• Memory problems

• menstrual problems

• Hyperlipidemia

• Recurrent infections

• Sensitivity to cold

• Cold hands and feet

• Fog in my head

• Thinning hair

• Constipation

• Dyspnea

• Impaired kidney function

• Muscle weakness and joint stiffness

*According to The Clinician's Handbook of Natural Medicine.

Due to the high prevalence of iodine deficiency worldwide, and the resulting serious health problems, there is much more focus in the medical community on adding more of this mineral to a person's diet than on reducing it.

There are several reasons:

1. Decreased dietary iodine intake.

   Unlike nutrients such as calcium, iron, or vitamins, iodine is not found naturally in certain foods; rather, it is present in the soil and absorbed through foods grown in that soil.

   Iodine is obtained primarily through the diet, but it can also be obtained from supplements. Higher exposure to certain chemicals found in processed foods unfortunately reduces iodine absorption.

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   For example, bromine, found in many packaged industrial foods, has been reported by researchers to affect the absorption of iodine from foods to varying degrees. Bromine is able to displace iodine and can lead to higher rates of iodine deficiency.

    

2. Depletion of the amount of iodine contained in soils.

   When it comes to soil depletion, research indicates that around the world, soils contain varying amounts of iodine, which in turn affects the amount of this mineral in crops. In some areas, mineral-deficient soils are more common, making people more likely to develop a deficiency.

    

   Deficiency reduction efforts, known as “salt iodization programmes”, are helping to reduce shortages in parts of the poor world where adverse health effects are high. But the surest way to prevent deficiency (and the safest) is to increase your intake of iodine-rich foods.

    

1. Selenium deficiency

   An iodine deficiency combined with a selenium deficiency can lead to an imbalance in the thyroid gland. One of the most serious manifestations of thyroid imbalance is goiter. Studies have shown that many people diagnosed with iodine deficiency were also deficient in selenium. The thyroid gland needs both selenium and iodine to produce adequate hormone levels, but when there is a deficiency of one or both, it results in low thyroid hormone levels. This is why adequate levels of iodine are essential for adequate thyroid function.

   Iodine is known to play a vital role in thyroid health while selenium is critical for iodine utilization. When selenium levels are low, the thyroid gland will work harder to produce thyroid hormones, and it will be difficult for the body to change these hormones into forms used by cells. Therefore, it is important to close both of these deficiencies in order to restore thyroid health.

    

2. Pregnancy

   According to the journal Pediatrics, about a third of pregnant women in the US are iodine deficient. Currently, only 15 percent of breastfeeding and pregnant women take iodine supplements.

    

   Supplemental iodine is usually in the form of sodium or potassium iodide. Severe iodine deficiency is associated with mental and physical growth retardation, and even mild iodine deficiency can impair brain function in infants. The supplement should include at least 150 micrograms of iodide and use iodized table salt. The combined intake of nutritional supplements and food should be between 290 and 1100 micrograms per day.

   https://www.webmd.com/vitamins/ai/ingredientmono-35/iodine

    

3. Tobacco smoke

   Tobacco smoke contains a compound called thiocyanate. The inhibitory effect of thiocyanate on iodide uptake occurs through competitive inhibition of the iodide transport mechanism and may be responsible for the decrease in iodide levels. Other substances in tobacco smoke that can impair thyroid function are the metabolites of hydroxypyridine, nicotine, and benzopyrenes. Tobacco smoke not only affects thyroid function, but can also block the action of thyroid hormones.

   https://pubmed.ncbi.nlm.nih.gov/7833671/

    

1. Fluoridated and chlorinated water

   Tap water contains fluoride and chlorine, which inhibit the absorption of iodine. In a study where researchers used the Wechsler Intelligence Test to determine the IQ of a total of 329 children aged eight to 14 living in nine high-fluorine, low-iodine villages and seven low-iodine villages. Children from high-fluoridated, low-iodine villages were found to have lower IQs than children from low-iodine villages.

    

2. Goitrogens

   Eating raw cruciferous vegetables (cauliflower, broccoli, cabbage, Brussels sprouts) can affect thyroid function as they contain goitrogens, substances that suppress the thyroid gland by interfering with hormone production. People with iodine deficiency are at risk when consuming these foods.

   https://pubmed.ncbi.nlm.nih.gov/8675242/

    

Low iodine status and low iodine diets are associated with an increased risk of thyroid disease, but there are also potential thyroid and hormonal risks associated with taking too much iodine, especially from supplements containing it in the iodide form.

According to the USDA, the recommended amount of iodine by age and gender is as follows:

• Birth to 6 months: 110 mcg

• 7-12 months: 130 mcg

• 1-8 years: 90 mcg

• 9-13 years old: 120 mcg

• 14 years and older: 150 mcg

• Pregnant women: 220 mcg

• Breastfeeding women: 290 mcg

What is the best way to reach these recommended levels? By eating more iodine-rich foods, especially those that naturally contain this mineral and are not fortified with vitamins.

excess iodine

An iodine overdose of more than 2,000 milligrams can be dangerous, especially in people diagnosed with tuberculosis or kidney disease. Excess iodine can lead to papillary thyroid cancer and hyperthyroidism rather than prevention. Pregnant women and breastfeeding mothers should be careful not to take iodine except in specifically prescribed doses.

As mentioned earlier, too much iodine can lead to thyroid disease, as it has the potential to cause thyroid goiter in the same way as iron deficiency. People with Hashimoto's disease, thyroiditis, or some cases of hypothyroidism should be careful to talk to their doctors about how much iodine they should be taking.

High iodine intake can cause some of the same symptoms as iodine deficiency, including goiter, elevated TSH, and hypothyroidism, because excess iodine in susceptible individuals suppresses thyroid hormone synthesis and thereby increases TSH stimulation, which can cause goiter. Iodine-induced hyperthyroidism can also result from high iodine intake, including when iodine is administered to treat iodine deficiency. Studies have also shown that excessive iodine intake causes thyroiditis and papillary thyroid cancer. Cases of acute iodine poisoning are rare and are usually caused by very large doses. Symptoms of acute poisoning include burning in the mouth, throat, and stomach, fever, abdominal pain, nausea, vomiting, diarrhea, weak pulse, and coma.

Reactions to excess iodine and the doses required to cause side effects vary from person to person. Some people, such as those with autoimmune thyroid disease and iodine deficiency, may experience adverse effects when taking iodine that is considered safe for the general population.

For most people, the intake of iodine from foods and supplements is unlikely to exceed the norm. Long-term consumption above the recommended amount increases the risk of adverse health effects.

Are iodine salts and nutritional supplements useful?

More than 70 countries, including the United States and Canada, have public health salt iodization programs, and 70 percent of households worldwide use iodized salt, according to the USDA.

The original purpose of salt iodization was to prevent deficiency, so in the 1920s in the US, manufacturers began adding iodine to table salt.

On average, every eighth teaspoon of iodized salt in the US contains about 45 micrograms of iodine. By law, food manufacturers almost always use non-iodized salt in processed foods, and include salt as iodized in the ingredient list on products that use iodized salt. This is to prevent very high iodine intake, given that most salt intake comes from processed foods.

It is best to use real salt, either Himalayan or Celtic sea salt. Sea salt contains over 60 micronutrients and does not pose the same risk of excessive iodine intake as table salt. It is also much more natural, healthy and delicious.

Let's summarize the information and outline the main conclusions:

• Iodine is an essential mineral that enters the body through certain foods and salts. We need it to create thyroxine (hormone T4) and triiodothyronine (T3), two main hormones produced by the thyroid gland that control many important functions.

• Unfortunately, many people are deficient in this mineral, which makes consuming iodine-rich foods even more important. Low iodine intake can lead to symptoms such as poor digestion, dry mouth, skin problems, poor concentration, muscle pain, weakness, and more. The best way to safely increase your iodine intake is to regularly include iodine-rich foods such as eggs, seaweed, vegetables, legumes, and fish in your diet.