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

Abstract

Background 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. Methods 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. Results 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. Conclusions 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.

Can Mild-to-Moderate Iodine Deficiency during Pregnancy Alter Thyroid Function? Lessons from a Mother–Newborn Cohort

“…It may be desirable to develop a rapidly adaptable and regional electronic tool for detecting iodine intake in public. Unlike Israel, other developed countries have professional software that may assist RDs in calculating iodine intake, although they cannot modify nutrition, and highlighting nutritional errors [9][10][11][12]16,29]. Accurately evaluating annual chemical iodine intake is close to impossible.…”

“…In a recent national iodine survey, the iodine status among pregnant women residing in this sub-district was similar to that of the overall pregnant women population (64 µg/L vs. 61 µg/L, respectively), as assessed by median UIC [4]. Although WHO recommends USI as a method for achieving and maintaining adequate iodine intake in the public, Israel remains one of the last developed countries to have no policy mandating salt fortification [6,12]. It is remarkable that this policy gap exists even though iodine deficiencies (whether mild, moderate, or severe) affect populations at all levels of economic development [13].…”

“…Clinical and biochemical data on maternal and neonatal thyroid function in regions with mild-to-moderate iodine deficiency are limited. The Ashkelon sub-district of Israel is a geographical region with an identified reliance on iodine-diluted desalinated seawater in a country without universal salt iodization (USI) [4,[10][11][12]. In a recent national iodine survey, the iodine status among pregnant women residing in this sub-district was similar to that of the overall pregnant women population (64 µg/L vs. 61 µg/L, respectively), as assessed by median UIC [4].…”

“…Moreover, a recent systematic review and meta-analysis suggested that USI alone may not be enough to ensure iodine sufficiency during pregnancy [14]. In addition, the Israeli national biomonitoring program reported persistent population and maternal iodine deficiency (with a median UIC of 62.2 µg/L among 120 childbearing age women) and a low prevalence of self-reported iodized salt use among adults (5.4%, N = 233) [12]. Given the possible maternal and neonatal thyroid dysfunction due to mild-to-moderate iodine deficiency, we aimed to investigate and describe the association between iodine intake in pregnancy and both maternal and neonatal thyroid function in this population.…”

Examining the Influence of Desalinated Water on Iodine Concentration in Tap Water in Israel

“…According to the Israel Ministry of Health (2017), drinking water from different nondesalinated sources contains varying concentrations of iodine (2-150 µg I L -1 ), but these results do not reflect the real situation with the concentration of iodine in end-user taps [18]. Barnett-Izhaki et al (2022) have noted that non-desalinated water in Israel has relatively low iodine levels (4-20 µg I L -1 ) [19]. Ovadia et al (2013) showed possible iodine deficiency among 76% of the participants, examined in Ashkelon District in Israel.…”