Iodine is a naturally occurring element that is counted among the trace elements and is a vital nutrient for humans. It is absorbed through our food and is essential for the formation of the thyroid hormones T3 (triiodothyronine) and T4 (tetraiodothyronine). These hormones are involved in the control of growth, bone formation, energy metabolism and brain development.

Iodine occurrence in soil and water can be subject to strong fluctuations. As a result, the contents in animal and plant foods also vary greatly. Iodine-rich food sources include marine fish and seafood, seaweed and mineral waters. Provided that iodine-enriched feed is used for livestock, meat, eggs, milk and dairy products also provide appreciable amounts of iodine. Vegetable foods contain lower iodine levels.

Dietary iodine deficiency leads to an insufficient concentration of thyroid hormones in the blood and consequently to a growth in the size of the thyroid gland (goiter formation) in order to compensate for the deficiency by increased production of thyroid hormones. A pronounced iodine deficiency can lead to hypothyroidism, which causes a number of complaints and negative effects on the organism.

Excessive iodine intake can also lead to impaired thyroid function. Causes often include the use of iodine-containing contrast media and iodine-containing medications or excessive consumption of iodine-rich dietary supplements and seaweed. Infants, pregnant women, and the elderly, as well as individuals with thyroid disease, are particularly susceptible. However, overdoses are hardly to be feared via the normal diet and iodized table salt.

In recent years, seaweed and algae products have become increasingly available on the European market. These products are characterized above all by a highly variable and often high iodine content. In most cases, there is a lack of information on preparation and recommended consumption, which can lead to the intake of very high amounts of iodine and excessive iodine consumption.

There are currently no EU maximum levels or national regulations for iodine in seaweed and seaweed products. In 2018, the European Commission published Recommendation (EU) 2018/464 on the monitoring of metal and iodine concentrations, according to which Member States should examine and monitor seaweed, algae and products thereof for their iodine content. In Austria, this recommendation is implemented within the framework of official control. The samples are examined and assessed by us. Labelling deficiencies were found in the products objected to, including missing warnings regarding iodine content and incorrect or missing consumption quantities. Other products were found to be harmful to health due to their very high iodine content.

• Adhere to the consumption recommendations and preparation instructions on the packaging of seaweed and seaweed products.
• Do not consume seaweed and seaweed products if the labeling is missing or inadequate.

The European Food Safety Authority (EFSA) has set the tolerable upper intake level for iodine at 600 µg/day for adults. Lower tolerable upper intake levels (ULs) have been derived for children depending on their age: 200 μg/day for 1- to 3-year-olds, 250 μg/day for 4- to 6-year-olds, 300 μg/day for 7- to 10-year-olds, 450 μg/day for 11- to 14-year-olds, and 500 μg/day for 15- to 17-year-olds. As Austria suffered from iodine deficiency for many decades, older people in particular have developed autonomous centers in their thyroid glands. An excess supply of iodine can activate these autonomous centers and cause hyperthyroidism. As a precautionary measure, the ÖGE recommends that adults do not exceed an iodine intake of 500 µg/day through food.

Without specific information on the quantity of algae used, how it is prepared and cooked, and the amount of these products consumed, very high amounts of iodine can be ingested, far exceeding the tolerable daily intake. Therefore, consuming these products can have a negative impact on consumer health. Young children, pregnant women, and older people are particularly sensitive.