-Automatic translation

The iodine level in milk in the Icelandic food composition database (ÍSGEM) is now 37 micrograms per 100 millilitres, compared to 11 micrograms per 100 millilitres previously. The updated value means 100 ml of milk provides about 25% of the recommended daily iodine intake for adults, which is 150 micrograms per day.

New calculations using data from a national survey of adults' diets from 2019 to 2021 found that the average iodine intake among participants was 243 micrograms per day, compared with 136 micrograms per day in previous calculations. The updated calculations therefore give a new picture of adults' iodine intake in Iceland and show that the average intake was considerably higher than the recommended daily intake.

Iodine intake varies between groups

However, iodine intake varied among participants. A quarter of participants received 102 micrograms of iodine per day or less, which is 68% of the recommended daily intake. Iodine intake was lowest among women aged 18–39 years, with a quarter of them receiving 80 micrograms or less per day. In contrast, a small proportion of men had quite high iodine intake, with 5% receiving 1254 micrograms per day or more. The tolerable upper intake level (UL) for iodine is 600 micrograms per day, based on habitual daily intake over a longer period of time.

^{Table 1. Iodine, μg/day. Mean, percentile – newly updated values.}

^{Table 2. Iodine, μg/day. Mean, percentile – newly updated values. Men by age groups.}

^{Table 3. Iodine, μg/day. Mean, percentile – newly updated values. Women by age groups.}

Dairy products and fish are the main sources of iodine

Iodine is an important trace element needed to produce thyroid hormones. It plays an important role in the body, especially during pregnancy, as it supports the fetus's normal growth and development. The main dietary sources of iodine are milk, dairy products, and lean fish. Dietary recommendations suggest 350–500 millilitres of milk and dairy products per day. In general, avoid high-sugar or high-fat dairy products, or those containing sweeteners. If you use plant-based milk and plant-based dairy products instead of milk and dairy products, choose products with added nutrients, such as calcium, iodine, vitamin D, and vitamin B12. It is also recommended to eat fish two to three times a week, including oily fish once a week.

Who needs iodine as a supplement?

People who do not consume milk, dairy products, or fish, for example due to allergies or other reasons, should take an iodine supplement. This is especially important for women planning to become pregnant. Pregnant women should avoid kelp and kelp supplements, as their iodine content can be very high and may exceed levels considered safe during pregnancy. Kelp may also contain contaminants that could harm the developing fetus.

It should be noted that the iodine intake estimates presented in the report Main Results of the Icelandic National Dietary Survey 2019–2021 were based on iodine values that have since been updated, as shown in the tables accompanying this announcement.

The importance of iodine supplementation for people who do not consume dairy products or fish is therefore emphasised. Pregnant women and infants are particularly vulnerable to iodine deficiency. Those who need further advice are encouraged to consult healthcare professionals providing maternity and infant care.

Iodine status of young children

In 2024–2025, the Directorate of Health conducted a study to assess the iodine status of children aged 2–3 years. Preliminary results indicate that iodine status in this age group meets World Health Organisation (WHO) criteria. The findings are expected to be published in 2027.

Summary

Updated estimates of iodine intake among adults in Iceland provide a considerably more favourable picture than previous estimates suggested. However, they also show substantial variation in iodine intake across population groups.

Both insufficient and excessive iodine intake can adversely affect thyroid function. Therefore, it is important to ensure adequate iodine intake without exceeding recommended levels. Milk and dairy products (except cheese), as well as fish, are important dietary sources of iodine and can help ensure adequate intake when consumed according to dietary recommendations. The recommended daily iodine intake for adults is 150 micrograms.

These findings also highlight the importance of regularly updating food composition data, as changes in food production and composition can significantly influence estimates of nutrient intake.

More informations
Jóhanna Eyrún Torfadóttir, Project Manager, Nutrition
johanna.e.torfadottir@landlaeknir.is
Hólmfríður Þorgeirsdóttir, Project Manager, Nutrition
holmfridur.thorgeirsdottir@landlaeknir.is