The mineral iodine (usually in the form of iodide) is considered a nutrient in the diet of humans as well as many animals and is an essential trace element. Iodised salt in particular is used as iodised food (enriched with iodine data) to prevent iodine deficiency. The iodine content in foods was determined per Regulation (EC) No. 1925/2006 (Enrichment Regulation) for it to be permitted to be advertised within the scope of health-related claims according to Regulation (EC) No. 1924/2006 (Health Claims) in the European Union (declared according to the national food labelling regulations in Germany, Austria and Switzerland). It is often added for this purpose, mostly as calcium iodide. Iodine is also added to ready-to-eat pet food, for example in most cat and dog food, but bird food (e.g. for canaries) can also be iodized. For the addition of iodine to slaughter animals, maximum levels are set in the EU on the recommendation of or following consultation with the European Food Safety Authority (EFSA). 

In Germany and more broadly in Europe, iodine compounds are present in the soil in too small quantities. As a result of iodine prophylaxis, which mainly consists of the iodination of table salt ('iodine salt') and the iodination of feedstuffs in agriculture, the iodine supply in Germany could be improved to such an extent that ioduria in children - which is considered the most reliable criterion for assessing the iodine supply - reached a median of 117 µg/l in a large random sample between 2003 and 2006. This was in the lower range of the range recommended by the World Health Organization (WHO) of 100 to 200 µg/l. According to WHO criteria, Germany is thus considered to be sufficiently supplied with iodine. Nevertheless, 36% of the population in Germany suffer from a mild iodine deficiency and 21% from a moderate to severe iodine deficiency.