Iodine intake from food and iodised salt in Italian adults
What it found
In 2219 Italian adults, iodine intake rose with salt intake, but most people still did not reach the European iodine target.
About 57% of iodine came from food and 43% from salt.
What they found
Studies in people
Iodine rises with salt
Iodine intake went up step by step across groups with higher salt consumption, in both men and women. The link stayed significant after accounting for age, sex and BMI.
Most missed iodine target
Overall, 71.5% of participants had iodine intake below the European Food Safety Authority adequate level of 150 micrograms a day. This was 78.7% of women and 64.8% of men.
Salt above WHO limit
Almost everyone, 94.7%, consumed more than 5 g of salt a day. This was 91.5% of women and 97.6% of men.
Where iodine came from
The authors estimated that about 57% of iodine intake came from food and about 43% from salt. Iodised salt made up 24% of total salt intake.
Food sources of iodine
Milk and yoghurt supplied 22 to 29% of iodine from food, and fish supplied 20 to 22%. Cheese, meat and eggs were also major sources.
Low salt, low iodine
Most people who kept salt intake below the WHO limit of 5 g a day did not reach adequate iodine intake. Adequate iodine was only seen at much higher salt intakes, with median salt intake of 16.7 g/day in the whole population and 18.1 g/day in men in the highest group.
What the authors conclude
- They say that in this sample, adequate iodine intake depended on eating large amounts of salt.
- They advise continuing to encourage the use of less salt but only iodised salt, including in catering and food production.
- They suggest that more iodine could also come from fortifying animal food and eating more iodine-rich foods like milk, dairy and fish.
How it was done
Italy's iodine programme relies on iodised salt, and the authors wanted to see how salt consumption and iodine intake relate in real life. They also wanted to estimate how much iodine comes from food and how much from iodised salt.
They studied 2219 adults aged 25 to 79 from all Italian regions, surveyed between 2008 and 2012. Salt and iodine intake were measured from 24-hour urine, and iodine from food was estimated with a food questionnaire.
What it can’t tell you
- The study measured iodine and salt intake at one point in time, so it cannot show that changes in salt intake directly cause changes in iodine intake.
- A single 24-hour urine collection may not reflect a person's usual intake over time.
- The data were collected between 2008 and 2012, so they may not reflect current iodine or salt intake in Italy.
Who paid
- Funding
- Funded by Italian Ministry of Health; Heart Care Foundation - HCF; Federico II University of Naples; Italian National Institute of Health (from the PubMed record).
- Conflicts
- PS declares to be an unpaid member of WASSH (World Action on Salt, Sugar and Health). All the other authors have nothing to disclose.
- Authors work at
- Federico II University of Naples Medical School, Italy; Italian Ministry of Health, Italy; Italian Association of Hospital Cardiology, Italy
The paper
- Title
- Iodine Intake from Food and Iodized Salt as Related to Dietary Salt Consumption in the Italian Adult General Population
- Type
- Study
- Evidence
- Studies in people
- Summarised from
- Full text
- Cite
- Iacone R, Iaccarino Idelson P, Russo O, et al (2021). Iodine Intake from Food and Iodized Salt as Related to Dietary Salt Consumption in the Italian Adult General Population. Nutrients. doi:10.3390/nu13103486Free full textPubMed 34684487DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error