MEAL Data on the Iodine Supply in Germany
Iodine is an essential trace element that must be consumed with the diet. Both, an insufficient and an excessive iodine intake, can be associated with health risks.
Current intake estimates based on the levels of iodine from the BfR MEAL study in combination with consumption data from the National Consumption Study II (NVS II) show that women with an average iodine intake of 99 micrograms per day, have a lower iodine intake than men with 115 micrograms per day. With an average of 92 micrograms per day, adolescents (14-18 years of age) have a lower iodine intake than adults. When interpreting these results, it is necessary to consider that non-iodized table salt was used in the preparation of the foods in the MEAL study kitchen. Therefore, the intake from natural sources and industrial use as well as from the use of iodised salt in the household were considered separately. Iodized table salt is used in the households by about 84% of the population in Germany. It is estimated that women and men have a median additional intake of about 18 and 21 micrograms of iodine per day, respectively, using iodized table salt for food preparation (BfR, 2021). Using iodised table salt in the household would result in a higher median iodine intake of 117 micrograms per day for women and 136 micrograms per day for men, but this is still below the recommended intake. The calculations also show that the iodine intake of the majority of men and women is below the mean estimated requirement.
According to the European Food Safety Authority (EFSA), no health impairments are to be expected for adults, even with a long-term intake of up to 600 micrograms of iodine per day (SCF, 2002). Since iodine deficiency was widespread in Germany until the 1980s, functional autonomies of the thyroid gland are still to be expected, especially for older people. This population group may have a higher sensitivity to iodine and may develop hyperthyroidism resulting from excessive iodine intake. Therefore, a maximum tolerable daily intake of 500 micrograms of iodine per day has been set for adults in Germany. Daily iodine intake levels of over 500 micrograms were estimated in only two of the 13,926 participants in NVS II (0.014%).
In the BfR MEAL study, all 356 foods of the MEAL food list were analysed for iodine. Based on data of NVS II, the MEAL food list covers at least 90% of the average foods consumed by the population in Germany. For iodine analysis, a total of 840 pooled samples were prepared consisting of 15 to 20 individual foods each. The pooled samples represent the combinations of different purchasing regions (national, east, south, west, north), times of purchase (non-seasonal, different seasons) and types of production (unspecific, organic, conventional). The 356 foods were assigned to 19 main food groups. For chronic dietary exposure assessment for adolescents and adults in Germany, the iodine levels analysed in various foods of the BfR MEAL study were combined with consumption data from 13,926 participants of the NVS II study. Milk and milk products as well as iodine from iodised table salt, especially from processed foods, make relevant contributions to the iodine supply of the population in Germany.
Overall, based on the MEAL data in combination with NVS II data, the iodine intake of the population in Germany is not sufficient to ensure an adequate supply of iodine. A broader use of iodized table salt should therefore be aimed for, especially in artisanal and industrially produced foods.
Further information is available in the BfR Opinion of 09.02.2021: www.bfr.bund.de/cm/343/ruecklaeufige-jodzufuhr-in-der-bevoelkerung-modellszenarien-zur-verbesserung-der-jodaufnahme.pdf
SCF (2002). Opinion of the Scientific Committee on Food on the Tolerable Upper Intake Level of Iodine:https://www.efsa.europa.eu/sites/default/files/efsa_rep/blobserver_assets/ndatolerableuil.pdf