Want to know more about the trace element iodine? Then you'll find what you're looking for here. We start with a profile and continue with intake, daily requirement, importance, overdose, deficiency, test variants and ways to cover the daily requirement. You will also find information about the iodine supply in a plant-based diet and which forms of food supplements can be useful.
Here is in advance a short Overview for you:
Notice: This article is not a substitute for medical advice, but merely provides general information about iodine. Please consult your doctor if you feel unwell or want to prevent health problems with medical care.
Iodine STECKBRIEF at a glance
Assignment: Trace element, in the periodic table part of the halogens
Synonyms: Iodine, older names are iodium, iodine and iodina
Important for: Co-factor for the thyroid gland, brain development, bone formation
Daily requirement: 200 µg per day from 13 to 50 years of age, thereafter 180 µg per day1
Recording: through food intake or dietary supplements
Overdose: Possible due to excessive consumption of certain algae or food supplements
Deficiency symptoms: impaired thyroid function, among other things
Food: certain algae, iodized salt
Food supplement: As powder, tablets, capsules or drops
How to ingest iodine?
The trace element iodine is repeatedly associated with the Thyroid health associated with iodine. European soils are said to be very poor in iodine and therefore very few plants contain significant amounts of iodine. Meat and dairy products can contain considerable amounts of iodine, but only if the animals are fed iodized feed. Unfortunately, it is rare to find precise information about this, so that an iodine supply from animal products is currently rather unreliable and difficult to plan is.
So how can you get iodine? Some types of algae, iodized salt and, if necessary, food supplements are suitable for covering your daily iodine requirements. You can find more information about the individual types of algae in the chapter Foods.
What is the daily requirement of iodine?
According to the German Nutrition Society (DGE), the daily iodine requirement is graded according to age. That's why I have a clear table for you here:
| Age | Recommended intake in µg |
| 1 to under 4 years | 100 |
| 4 to under 7 years | 120 |
| 7 to under 10 years | 140 |
| 10 to under 13 years | 180 |
| 13 to under 51 years | 200 |
| 51 years and older | 180 |
| Pregnant | 230 |
| Breastfeeding | 260 |
However, when it comes to iodine, a lot does not help a lot. It is much more the case that there is a range that is beneficial to health. You can find out more about maximum iodine intake in the chapter Overdose. Basically, it should also be said about reference values that they vary depending on the institution and can only ever be a guideline, as each person is individual. The reference values are based on current studies and assumptions, which may of course change in the future.
What is the importance and function of iodine in the body?
Iodine is crucial in the body to ensure that the Thyroid gland produce hormones can. These hormones influence the human Metabolismwhich can falter in the event of an iodine deficiency.2 These are the hormones triiodothyronine (T3), which is the active form, and thyroxine or tetraiodothyronine (T4), which is the storage form. A selenium-dependent enzyme called deiodase is required to convert the storage form into the active triiodothyronine. Triiodothyronine has an effect on the metabolism, the Protein synthesis at the cell level, as well as a healthy brain and bone development off.
At the same time, however, it should be said that many more Nutrients such as iron or the aforementioned selenium for deiodase make a significant contribution to thyroid health and performance. Hypothyroidism can therefore not be caused solely by an iodine deficiency, but can have several causes.
The Iodine functions at a glance:
- Hormone production in the thyroid gland
- Protein synthesis at the cellular level
- Healthy brain and bone development
- Supports blood formation
- Optimizes energy, homocysteine and folic acid metabolism
- Supports the formation of messenger substances in the nervous system
Is a B12 overdose possible?
As already mentioned, there is not only a recommended minimum intake for the trace element iodine, but also a maximum recommended daily intake. This maximum intake is called the Tolerable Upper Intake Level (UL). The European Food Safety Authority (EFSA) recommends limiting iodine intake to a UL of 600 µg per day.3
An even higher UL of 1,100 µg iodine per day is set by the National Institutes of Health.4 Personally, I would recommend that you rather orientate yourself to the recommended daily intake and, above all, listen to your own body feeling. Especially when it comes to nutrition, you are often the best doctor and can sense which foods are good for you and which you don't tolerate so well.
Such high iodine intakes of 600-1,000 µg per day are possible, especially when certain types of algae are consumed. Furthermore, a Excessive iodine supplementation an overdose can occur. With iodized salt, however, the iodine content of 20 µg per gram of salt is too low for the upper limits mentioned to be exceeded with normal salt use.5
Symptoms of an overdose: including nausea, vomiting and fever.
When does iodine deficiency occur?
Iodine deficiency occurs when the body is supplied with less iodine through the diet than it needs for its processes. The first symptoms tend to be less specific, such as Tiredness, concentration problems or low mood. I therefore recommend regular blood tests to detect potential deficiencies at an early stage. You can find out which value is the right one for detecting your iodine balance in the chapter Tests.
In principle Vegans and vegetarians are more at risk of iodine deficiencybecause iodine is mainly found in animal products. However, this is not because animal products contain iodine per se, but because the animals are supplemented with iodine via feed and thus accumulate it.6 Likewise Smokers particularly at riskThe thiocynate contained in the smoke inhibits iodide transport.
Which tests are suitable to determine the iodine status?
Two tests are suitable for determining the iodine status. On the one hand the Excretion of iodine via the urine and on the other hand the TSH value. The TSH value is used to determine thyroid function. TSH stands for thyroid-stimulating hormone. This hormone is administered into the blood as required to stimulate hormone production in the thyroid gland. Sometimes the value is also referred to as TSH basal.
Iodine excretion should be between 100 and 200 µg/l with a good supply. A slight deficiency is present if excretion is below 100 µg/l. To be honest, these values made me a bit suspicious, as a healthy person excretes between 1.5 and 2 liters of urine per day, which would mean an iodine excretion of approx. 200-300 µg per day. This is already above the recommended daily intake. However, I have not been able to find any further information on this.
The right test: If you suspect hypothyroidism or an iodine deficiency, I would recommend that both values are determined and discussed with your doctor.
What foods contain iodine?
As already mentioned, iodine is mainly found in animal products, iodized salt and seaweed. That's why I'm going to give you some seaweed and list their iodine content per one gram dry weight:
- Kombu/Kelp (on average 1,500 μg per 1 gram)
- Dulse (on average 173 μg per 1 gram)
- Wakame (on average 160 μg per 1 gram)
- Nori (on average 35 μg per 1 gram)
For comparison: Iodized salt contains 20 µg per gram and is therefore significantly lower than the algae mentioned. Finally, due to the high iodine content of algae, cod is also a rich source of animal iodine with around 120 µg per 100 grams. It should also be noted that the values for some algae are subject to wide ranges. For example, kombu/kelp can contain between 500 and 11,000 µg of iodine per gram.
What do vegans and vegetarians need to know about iodine?
The DGE classifies iodine as potentially critical nutrient in a vegan diet.7 This is mainly due to the fact that iodine is primarily absorbed through animal products. However, it is perfectly possible to cover the iodine requirement in a balanced plant-based diet if algae are regularly integrated into the diet.
Finding the right iodine supplement
As already mentioned, you can use seaweed to effectively and fully integrate iodine into your diet. For example, you can simply mix small amounts of dulse into a smoothie. The taste is not noticeable at all. Incidentally, microalgae such as chlorella or spirulina contain far less iodine than the seaweed mentioned above and therefore only make a small contribution to covering your iodine requirements.
Basically, I only recommend supplementing iodine if you have an iodine deficiency, because the daily requirement cannot be covered by your diet alone. You should therefore take a blood test before supplementation and discuss this with your doctor. Excess iodine can also lead to hypothyroidism, as can a mild iodine deficiency.8
If you want to supplement iodine, you can find iodine in various forms such as Powder, capsules, tablets or drops. If you eat a plant-based diet and want to make sure that you meet your daily requirements for potentially critical nutrients such as iron, zinc or iodine, I can recommend the vegan multinutrient supplement:
- The Iodine capsules you get here*
- The Multi-nutrient preparation you get here*
Secure the iodine supply
Iodine is probably one of the most critically considered nutrients. This is mainly due to the fact that there are very different positions on the nutrient. You should therefore also critically scrutinize scientific studies, as these are sometimes based on false assumptions and can therefore produce inadequate or misleading results.
By having regular blood tests, you can check your values together with your doctor and, if necessary nutrition-related diseases avoid. Otherwise, as always, it is helpful to listen to your body's signals and eat a varied and healthy diet. to eat a wholesome diet.
Do you have any questions or suggestions about this article on iodine? Then please write me a comment.
All the best,
PS.: You want to know, why we live vegan? Find out our reasons in the linked article! And if you want to learn more about other nutrients, then take a look at the articles on Salutogenesis or Vitamin D.
References:
1 German Society for Nutrition e. V.: Iodine, https://www.dge.de/wissenschaft/referenzwerte/jod/?L=0. [23.05.2021].
2 Zentrum der Gesundheit: Covering iodine requirements - healthy and vegan,
https://www.zentrum-der-gesundheit.de/ernaehrung/ernaehrungsformen/vegane-ernaehrung/jodbedarf-decken-ia. [23.05.2021].
3 European Food Safety Authority: Tolerable Upper Intake Levels for Vitamins and Minerals, https://www.efsa.europa.eu/sites/default/files/efsa_rep/blobserver_assets/ndatolerableuil.pdf, [23.05.2021].
4 National Institute of Health: iodine, https://ods.od.nih.gov/factsheets/Iodine-HealthProfessional/, [05/23/2021].
5 G. Jahreis, M. Leiterer, A. Fechner: Iodine deficiency prophylaxis through proper nutrition: The contribution of milk, sea fish and iodized salt to iodine supply in Germany, https://www.researchgate.net/publication/263460391_Jodmangelprophylaxe_durch_richtige_Ernahrung_Der_Beitrag_von_Milch_Seefisch_und_Jodsalz_zur_Jodversorgung_in_Deutschland, [23.05.2021].
6 N. Rittenau (2018): Goodbye vegan cliché! Scientific answers to critical questions about vegan nutrition. VENTIL-Verlag.
7 Deutsche Gesellschaft für Ernährung e. V.: Supplement to the position of the German Nutrition Society on vegan nutrition with regard to population groups with special nutritional needs, https://www.dge.de/wissenschaft/weitere-publikationen/dge-position/vegane-ernaehrung/?L=0, [27.05.2021].
8 A. M. Leung, L. E. Bravermann: Consequences of excess iodine, https://www.ign.org/rp.htm?cmsaction=get_document&page_id=142002953, [May 27, 2021].
