Assessment of iodine intake in the Israel coastal area

Abstract

Background: Iodine intake is necessary to maintain normal thyroid function and prevent iodine deficiency disorders. In 1990, a resolution calling for universal salt iodination to eliminate iodine deficiency worldwide was taken by the World Health Organization and endorsed by some 130 countries. As of today, very little is known about iodine intake and the prevalence of iodine deficiency disorders in Israel, and the authorities do not require iodine enrichment of regular salt.

Objective: To assess the current level of iodine intake in an unselected group of residents from the Israeli costal area.

Methods: Spot urine samples were collected from three groups: Group A comprising 51 pregnant women attending the Womens Health Clinic at our institution, with a mean age of 32 years and at gestational week 28; group B consisting of 35 healthy subjects, mean age 38; and group C consisting of 16 euthyroid subjects harboring nodular goiters. Tap water and mineral water were also analyzed for iodine content. Iodine concentration was measured using the catalytic reduction of ceric ammonium sulfate method.

Results: When considering all groups together the median urinary iodine concentration was 143 micrograms/L, with 27% of the study population having concentrations under 100 micrograms/L and 7.8% under 50 micrograms/L. Values were distributed similarly between sites of residency, and no significant differences were seen between groups. The mean iodine concentration for tap drinking water was 22.8 micrograms/L (range 0.5-53.5 micrograms/L) and for mineral water 7 micrograms/L (range 0-15 micrograms/L).

Conclusions: Overall, iodine intake appeared to be satisfactory in our study population, however mild deficiency may exist in up to 26% of this group. A nationwide survey is needed to better determine the status of iodine intake in Israel, allowing for recommendations on salt-iodine enrichment in the future.