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Assessment of iodine fortification of salt in the Danish population

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Abstract

Purpose

We assessed the effect of the current iodine fortification level (20 µg/g household salt and salt included in bread and bakery products) on inadequate and excessive intake in the general Danish population. Intake models with/without the contribution from food supplements and effects of excluding specific food groups were evaluated.

Method

Data from the Danish National Survey of Dietary Habits and Physical Activity in 2011–13 (N = 3946, aged 4–75 years) stratified by age-group and sex were used to estimate habitual dietary iodine intakes, and compared with established dietary reference values.

Results

The proportion with an estimated inadequate iodine intake was ≤ 3% for males and ≤ 5% for females, except for 15–17-year-old girls, where the probable prevalence of an inadequate intake was 11%. Including the contribution from food supplements gave similar results (10%). High intakes (as defined by 95th percentile) from food sources generally did not exceed the tolerable upper intake level (UL). However, for the youngest age-groups (4–6-year-old boys/girls and 7–10-year-old boys), the 95th percentiles exceeded the UL with 11%, 4% and 7%, respectively, when food supplements were included in the estimates. Especially exclusion of dairy products and bread led to an inadequate intake for both boys and girls.

Conclusion

The current fortification level may provide an inadequate iodine intake for some females and on the other hand lead to excessive intakes in the youngest age-groups. The study shows the importance of choosing iodine-rich alternatives when excluding major sources of iodine in the Danish diet.

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Availability of data

Data from this paper can be made available upon request to the corresponding author.

Code availability

Code for this analysis can be available upon request to the corresponding author.

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Funding

This study was partly financed by the Ministry of Food, Agriculture and Fisheries of Denmark.

Author information

Authors and Affiliations

  1. Division for Diet, Disease Prevention and Toxicology, National Food Institute, Technical University of Denmark, Kgs. Lyngby, Denmark

    Malene Outzen, Cecilie E. Lund & Gitte Ravn-Haren

  2. Division for Food Technology, National Food Institute, Technical University of Denmark, Kgs. Lyngby, Denmark

    Tue Christensen & Ellen Trolle

Authors
  1. Malene Outzen
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  2. Cecilie E. Lund
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  3. Tue Christensen
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  4. Ellen Trolle
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  5. Gitte Ravn-Haren
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Contributions

GRH and CEL designed the study. TC, MO and CEL analyzed the data. GRH, ET, and MO interpreted the data. MO and CEL wrote the first draft of the paper. All authors contributed to the manuscript and have read and approved the final version of the manuscript.

Corresponding author

Correspondence to Malene Outzen.

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Conflict of interest

The authors declare that they have no conflict of interest.

Ethics approval

The Danish National Surveys on Diet and Physical Activity have been conducted in accordance with the guidelines laid down in the Declaration of Helsinki and have been approved by the Danish Data Protection Agency. The Danish National Committee on Health Research Ethics has decided that, according to Danish Law, the studies do not require their approval.

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Verbal informed consent was obtained from all subjects.

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Outzen, M., Lund, C.E., Christensen, T. et al. Assessment of iodine fortification of salt in the Danish population. Eur J Nutr 61, 2939–2951 (2022). https://doi.org/10.1007/s00394-022-02826-x

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