Iodine: All you need to know about the essential trace element

Iodine is a vital trace element that the body cannot produce itself. It must therefore be consumed via the diet or in the form of dietary supplements. One of the main tasks of iodine is to ensure the correct functioning of the thyroid gland, for which it is required as a basic material for hormone production. The thyroid hormones not only influence our metabolism and growth, they also help regulate numerous bodily functions. Although we humans don’t need much iodine, it is still an essential part of maintaining our health.

A little iodine is present in many foods, but few really contribute to our daily iodine supply. Since the trace element is predominantly found in the oceans, marine products in particular have a high content. Oily sea fish such as cod, shellfish and tuna, as well as algae, are particularly rich in iodine. Dairy products and eggs also contain certain amounts of iodine, whereby the content depends on the animal feed. In many countries, table salt is also enriched with iodine to prevent shortages in the population.

The following foods in particular contain iodine:

• Seaweed (e.g. nori, wakame or bladder kelp)

• Sea fish (e.g. herring, mackerel or turbot)

• Iodised table salt

• Milk and dairy products*

• Eggs* 

* If the animal feed is enriched with iodine.

The trace element iodine is only needed by our body in small quantities, but it is still indispensable. Iodine performs its best-known function within the thyroid. It is required for the production of the thyroid hormones T3 (triiodothyronine) and T4 (thyroxine). These hormones affect the entire metabolism, the cardiovascular system and the body’s heat regulation. A stable iodine balance is therefore crucial for physical and mental performance.

In addition, a good iodine supply supports skin health, helps to develop the brain and cognitive abilities and can contribute to the healthy development of the foetus during pregnancy.

One of the best known consequences of iodine deficiency is hypothyroidism. In the event of an undersupply of iodine the thyroid gland cannot produce enough hormones. The additional intake of iodine can help to rebalance hormone production and alleviate the symptoms of underactivity. If you suffer from diagnosed hypothyroidism, you should consider targeted iodine intake in consultation with a doctor.

The skin also benefits from an adequate iodine supply. Iodine helps to keep the skin healthy by supporting the regeneration of skin cells. People who suffer from dry skin in particular report an improvement in their skin appearance through optimised iodine intake.

Iodine plays an important role in the fertility and development of a healthy foetus. For women who wish to have children, an adequate iodine supply is crucial, since iodine supports the development of the nervous system and the brain of the unborn child.

An iodine deficiency during pregnancy may increase the risk of malformations and negatively affect the child's mental development. Pregnant and breastfeeding women therefore require more iodine.

The daily need for iodine varies depending on age, gender and life circumstances:

• Infants under one year: 40-80 μg/day

• Children from 1 to under 7 years: 90-120 μg/day

• Children and adolescents aged 7 to under 19 years: 120-200 μg/day

• Adults under 51 years: 150-200 μg/day

• Adults over 51 years: 150-180 μg/day

• Pregnant women: 200-230 µg/day

• Breastfeeding women: 200-260 μg/day

No thyroid hormones without iodine. Accordingly, a lack of iodine can lead to hypothyroidism with serious health problems. In children, this can lead to physical and mental developmental disorders in the embryonic phase. Iodine deficiency can also trigger various symptoms in adults and in some cases even lead to enlargement of the thyroid gland (also called goitre).

Common symptoms of iodine deficiency include:

• Fatigue, lack of drive

• Sensitivity to the cold

• Weight gain despite unchanged diet

• Dry skin and hair loss

• Concentration problems

In certain life situations or when using uniodised table salt, the supplementary intake of iodine may be useful. Supplementing Iodine capsules is an easy way to contribute to your daily routine. In particular, people with an increased need, such as pregnant women, breastfeeding women or people with hypothyroidism, should consider taking it. However, when taking iodine as a supplement, care should be taken not to independently decide to exceed the recommended daily dose – i.e. without medical consultation.

Iodine is undoubtedly indispensable for our health. An overdose via food is highly unlikely. When specifically using nutritional supplements, the recommended daily dose should always be taken into account or medical advice should be sought to avoid side effects.

Too much iodine can impair the thyroid function and in rare cases trigger hyperthyroidism. However, side effects of this type usually only occur in the case of excessive intake.

Conclusion: Iodine is one of the nine essential trace elements. Even though our body needs only small amounts of it, it is indispensable. If too little iodine is ingested through food, the production of the thyroid hormones can suffer. This in turn can have far-reaching consequences for our health.