Results of the national biomonitoring program show persistent iodine deficiency in Israel

Adequate iodine intake is essential for human health, for normal thyroid function, and for attainment of full intellectual potential in children. In light of Israel's lack of a mandatory salt fortification policy, heavy reliance on desalination and low iodine intake from dairy products and seafood, there is concern in Israel that the population is iodine deficient. Indeed, the first Israeli National Iodine Survey in 2016 found a median urinary iodine concentration (UIC) of 83 µg/L among school age children, falling below the WHO's adequacy range of 100-299 µg/L for children.

In the framework of the National Human Biomonitoring Program in Israel, spot urine samples and questionnaire data were collected from 166 healthy children aged 4-12 years in 2020-2021. Urinary iodine concentrations were measured at the Ministry of Health National Biomonitoring Laboratory, using mass spectrometry. An international comparison of median urinary iodine concentrations (UIC) was performed taking into consideration the levels of desalinated water per capita, and fortification policies.

The overall median (interquartile range [IQR]) UIC was 80.1 µg/L (44.7-130.8 µg/L) indicating that the population's iodine status has not improved in the five years that have passed since inadequacy was first identified. When comparing 13 countries with population size above 150,000, whose desalinated water per capita was at least 1 m³, Israel and Lebanon were the only countries with median UIC below the WHO adequacy range.

There is an urgent need for mandatory salt fortification in Israel. Based on our international comparison, we conclude that the potential impact of desalination on iodine intake can be compensated for using the implementation of salt fortification policy. This study highlights the critical need for public health surveillance of nutritional and environmental exposures using human biomonitoring, with emphasis on vulnerable populations such as pregnant women and children.