The first national iodine survey conducted in Israel has revealed a high burden of iodine deficiency among Israelis, posing a high risk of maternal and fetal hypothyroidism and impaired neurological development of the fetus in Israel.

The International Child Development Steering Group has identified iodine deficiency (ID) as a key global risk factor for impaired child development, and the World Health Organization’s recommends routine monitoring of population–based data on urinary iodine every five years as a means of sustainable elimination of ID. Yet Israel is among the few countries that have never performed a national iodine survey, and does not provide iodine prophylaxis, even though some of its population has suffered from ID in the past. Israel similarly lacks current data on the incidence and prevalence of thyroid disease.

Now, researchers from the Hebrew University of Jerusalem, and their colleagues at Maccabi Healthcare Services and Barzilai University Medical Center in Ashkelon in Israel, and ETH Zurich in Switzerland, with support of the Iodine Global Network, have obtained the first nationally representative data about iodine status in the Israeli population. To do this, they collected pre–discard spot–urine samples, from 1,023 school–age children and 1,074 pregnant women, representing all regions and major sectors in Israel (Arab, Jewish secular and orthodox), during 2016 at the Maccabi Healthcare Services (MHS) central laboratory.

They found a high burden of iodine deficiency in the general population: 62% of school–age children and 85% of pregnant women fall below the WHO’s adequacy range.

The median urinary iodine concentration (UIC) among Israel’s pregnant women, only 61 micrograms iodine/liter and for school–age children, the median of 83 micrograms/liter suggest that the iodine status in Israel is amongst the lowest in the world. Iodine adequacy is defined by the WHO as a population median of 150–249 micrograms/liter for pregnant women and 100–199 micrograms/liter for school–age children. Virtually no differences were seen between different ethnicities and regions of the country suggesting that low iodine status is widespread and universal throughout the country.

Adequate iodine intake is essential for thyroid function and human health throughout life. Even mild iodine deficiency might prevent children from attaining their full intellectual potential, and mild to moderate ID has been linked with decreased cognitive performance. Iodine deficiency in utero and in early childhood impairs brain development, and severe iodine deficiency causes cretinism and goiter.

According to the researchers, the high burden of iodine insufficiency in Israel is a serious public health and clinical concern. By comparison to data from other countries with a similar extent of deficiency, these data suggest that there is a high risk of maternal and fetal hypothyroidism and impaired neurological development of the fetus in Israel. By extrapolation, given the rate of insufficiency in Israeli pregnant women, nearly all pregnant women and their children may be at risk, implying that the majority of the population could be unlikely to realize its full intellectual potential.

“The immediate implication of our findings is that we need to improve the public’s intake of iodine,” said Prof. Aron Troen, Principal Investigator at the Nutrition and Brain Health Laboratory, School of Nutrition Science, Hebrew University’s Robert H. Smith Faculty of Agriculture, Food and Environment.