John Myers
Iodine is essential to life and yet we consume less and less. In the future it could be even less – also because some experts vehemently warn against iodine.
Thyroid medication has been one of the most frequently prescribed medications in Germany for years. In the social networks, on YouTube and on our own pages, more and more people are talking about dangerous “forced iodization” in Germany. In fact, the working group Jodlack advocates that people consume more iodine – but is the dose too high and is more thyroid disease the result?
What does the body need iodine for?
Iodine is a trace element and is vital for the organism, including for growth processes, the development of the nervous system and thus the brain. Iodine regulates the metabolism and the cardiovascular system via the thyroid gland and its hormones. The iodine from food is built into the thyroid hormones thyroxine (T4) and triiodothyronine (T3).
What iodine dose is recommended?
The Federal Institute for Risk Assessment (BfR) recommends a daily iodine intake of 200 micrograms for adults. The critical dose above which no deficiency symptoms occur is 60 to 120 micrograms for a daily intake.
The situation is different for children, infants and pregnant women. Infants should get 40 to 80 micrograms of iodine per day, children between 100 and 200 micrograms per day depending on their age. Pregnant and breastfeeding women are recommended to consume between 230 and 260 micrograms of iodine per day. The World Health Organization (WHO) recommends slightly lower doses, around 150 micrograms for adults (or children and adolescents from the age of 12).
Do the recommended iodine dosages apply to everyone?
Individual fluctuations of around 20 to 30 percent are already taken into account in the recommended quantities. In this respect, they are intended as a sensible guideline for the vast majority. At the same time, an intake of around 100 micrograms per day is also safe for people with thyroid diseases such as Graves’ disease or Hashimoto’s. Elevated, daily intakes of more than 300 micrograms should be avoided. On the other hand, people who suffer from an enlarged thyroid gland as a result of iodine deficiency should consume larger amounts of iodine.
Different recommendations depending on the country and region
Depending on the country and region, however, there are different recommendations as to the amount that should be closed. Studies from China recommend no more than 800 micrograms, in the USA 1100 micrograms per day are set as the critical limit. In addition, symptoms of hypothyroidism could be expected. The large range indicates two things: humans seem to tolerate higher doses quite well and further, larger and better studies are needed to reliably define limit values and reasons for specific values.
In addition, there are very few people who are allergic to iodine. Symptoms of poisoning such as bronchitis, asthma or eye and skin irritation are therefore rare.
What happens with an incorrect dosage?
Both an iodine deficiency and an overdose lead to changes in the thyroid gland and its function over the long term. An iodine deficiency leads to an enlarged thyroid gland, the so-called goiter. This change in the organ is usually safe and harmless. However, prolonged iodine deficiency can lead to other more serious diseases. So-called iodine excesses, i.e. the long-term increased intake of iodine, can cause problems. Several results indicate that a rapid and then sustained increase in intake is problematic, especially after prolonged iodine deficiency.
Iodine poisoning only at around 15,000 micrograms
In studies, a permanently increased iodine intake has often led to subclinical hypothyroidism, i.e. the subjects did not show any symptoms of the disease. However, the studies were usually carried out in places where a high amount of iodine is consumed anyway due to iodine concentrations in the water or the typical diet.
Acute iodine poisoning is only present in amounts of around 15,000 micrograms – i.e. more than a hundred times the amount that people in Germany usually consume. Then vomiting can occur, but fatal consequences due to a coma are also possible.
Does too much iodine lead to autoimmune diseases such as Hashimoto’s or Graves’ disease?
Too little or too much iodine intake from the diet is very unlikely in the long term, and whether a long-term excess leads to autoimmune diseases is a topic of discussion again and again. Studies from Japan show, however, that increased intake, for example through diet, does not necessarily lead to more immune patients. The number of cases in Germany is also currently stable and, according to experts, does not show any noticeable association with the amount of iodine ingested, so other causes seem to be far more important. Since thyroid problems have become better known over the years, the increasing number of cases in some places can also be related to more frequent visits to the practice.
Contrast agent as a risk factor
However, so-called contrast agents are a recognized risk factor. The iodine-containing substances are used in medicine to make vessels visible in computer tomography images. For some patients, however, the benefits are associated with risks and the use of the funds must therefore be clarified in detail with the doctor. According to projections, these substances could be responsible for up to half of all new overactive thyroid glands – such as the autoimmune disease Graves’ disease. So the thyroid is working harder than usual.
In contrast, Hashimoto’s autoimmune disease is caused by chronic inflammation of the thyroid gland. After an overfunction, an underfunction sets in in the long term. The thyroid therefore produces less of the two thyroid hormones T3 and T4 than is usual in healthy people.
In principle, however, both autoimmune diseases sometimes show overfunctioning and sometimes underfunctioning. During therapy, it is important that the doctor adjusts the medication appropriately and discusses nutrition and thus iodine intake with the patient. Otherwise, incorrect treatment can also tip the diagnosis in the opposite direction.
Genetic disposition as a major risk
A genetic disposition is a major risk factor. There are also diseases associated with Graves’ disease, for example. This means the diseases could be mutually dependent and often occur together. These include type I diabetes, celiac disease and arthritis. They seem to promote Graves’ disease. However, the trigger of immune diseases cannot be clearly identified, for example whether it is a random error in the immune system.
However, the autoimmune diseases seem to occur particularly frequently after very stressful periods in which the immune system may have been disturbed. Doctors are demanding that the diseases have to be further investigated and characterized. Likewise, it must be examined to what extent the amount of iodine could shape the body of the fetus and infant during the development phases.
How common are thyroid dysfunction and autoimmune diseases?
The number of cases of diseases relevant to the thyroid gland are largely stable. However, a distinction must be made between manifest and latent diseases. The latter are patients who do not show any symptoms of the disease. However, the specific values show a clear trend.
TSH value decisive
The TSH value, which stands for a thyroid-stimulating hormone, is particularly decisive in the diagnosis. However, the reference values have been discussed for a long time. Elevated values indicate a hypofunction, but experts have been arguing about when to intervene for decades. However, it seems important that other factors are also included in the diagnosis in order to draw a more holistic clinical picture. The TSH value alone can show different symptoms and disease progression from patient to patient. If the values are abnormal, patients can discuss their iodine intake with their doctor.
Do thyroid drugs help against obesity?
An underactive thyroid can be the cause of altered metabolism and thus obesity. Many patients and those affected therefore seem sympathetic to getting this problem under control with thyroid preparations.
Doctors are increasingly reporting that patients are pushing them for treatment. But if the treatment is not necessary, it has side effects and risks – without necessarily leading to weight loss, as studies show.
Why is there an iodine deficiency working group in Germany?
While the iodine supply in China, the Congo or Japan tends to be oversupplied, the iodine levels in Germany are very low both in drinking water and in normal food. This is usually justified by the fact that the iodine-rich humus layer was washed away after the Ice Age and the soils in Germany are significantly less iodine-rich and this continues through the food chain. Diet otherwise has the greatest influence and is the reason why the Japanese tend to be oversupplied, for example due to iodine-rich algae.
40 percent of Germans have an iodine deficiency
On average, adults in Germany only take in 60 percent of the recommended amount of iodine. Around 40 percent of Germans also seem to suffer from a mild to severe iodine deficiency, as urine measurements have shown. In the long term, these people risk changes, disorders and chronic inflammation of the thyroid gland.
In order to prevent this, in 1984 the working group Jodlack was founded to raise awareness and encourage food and feed manufacturers to use more iodized salt. There is no legal requirement, the manufacturers and associations have only voluntarily agreed to the measure.
However, awareness has waned again in recent decades, and not only in Germany. People in this country consume much less iodine than in other European countries for which comparable data are available.
What is the current development?
According to studies such as the KiGGS study by the Robert Koch Institute, the iodine supply of children has improved compared to the 1980s. Despite this, the studies show that about a third of children remain malnourished, which can impede growth and development. In addition, the amount of iodine measured in urine has fallen again since the turn of the millennium.
Manufacturers do not add iodized salt
A possible reason: Most food manufacturers produce their goods for the international market. However, the voluntary requirement to put foods with iodised table salt on the shelves is invalid in other European countries. Many manufacturers have therefore stopped adding iodised table salt.
This is also reflected in the proportion of iodised table salt that is supplied to industry in large containers. This fraction has been at most a third since the mid-1990s, but has been declining steadily since 2004. Scientists and doctors are therefore calling for European and uniform regulations to improve iodine supply on a large scale.
Do I have to fear a “forced iodization”?
Relevant pages or comments in social networks can again and again unsettle and warn against a specified amount of iodine. But the statements and arguments are often misleading and wrong.
Permanent overdose unlikely
Correct: Yes, the daily dose can be exceeded with certain meals, but it is unlikely that you will exceed it permanently. The critical iodine dose of 500 micrograms per day, which the Federal Institute for Risk Assessment calls for, can hardly be reached over several weeks. The risk of overdose and poisoning is therefore rather unlikely. Acute poisoning was found in amounts of 15,000 micrograms, more than a hundred times the average intake in Germany.
With our meals, we exceed and fall below the recommended daily doses of all nutrients and minerals every day. Health consequences only develop if there is a deficiency over a longer period of time – or vice versa.
Our body simply excretes most of the excess nutrients. A possible overdose could be detected by the amount of iodine in the urine. Here, 300 micrograms are considered critical – that is more than twice the amount that adults in Germany take in on average.
How do I take more iodized salt?
If you season food at home, you can use iodised table salt. On average, however, the greatest salt content comes from ready-made or processed dishes such as bread, sausage products or convenience foods. If you eat in the canteen or in the restaurant, for example, you have no control over whether the chef insisted on iodized salt when you bought it. On the one hand, this can lead to undersupply for the majority of the population or to oversupply of risk groups with autoimmune diseases. A label or indication would be helpful here.
Sushi, fish and dairy products
The following applies to most people: foods containing iodine are sushi or algae, fish from overseas or the Mediterranean, and milk and dairy products. With them, the demand can be covered quickly. However, the intake should not be exaggerated – this can also be problematic for children and adults. Pregnant and breastfeeding women, who often do not meet their needs through diet, are advised to take iodine tablets on medical advice so as not to endanger the healthy development of the child.
