Evaluation of Urinary Iodine Concentration and Iodine Content of Households Salt in South of Tehran

Iodized salt is the main dietary source of iodine in Iran. Previous studies have shown sustainable elimination of iodine deficiency disorders in Iran. The aim of this study was to evaluate urinary iodine concentration and the iodine content of households salt in the south of Tehran in 2009. This cross-sectional study, 91 households were enrolled through randomized cluster sampling. A total of 147 adult subjects (62 males, 85 females), aged 18 and over, were selected from households to provide 24 hr urine samples. Urinary iodine and creatinine concentrations were measured by using the digestion method and autoanalizer assay, respectively. Daily salt consumption was estimated and household salt iodine content was measured by titration. Mean±SD iodine concentration of household salt was12.7±14.7 ppm, and 64.8 % of household salts contained < 10 ppm iodine. The median of Urinary Iodine Concentration (UIC) was 48.0 μg/l. There was no statistically significant difference in UIC, between men and women. The median daily salt consumption was 9.1 g. According to WHO/ICCIDD/UNICEF classification, 17.0, 30.6, 45.6 and 6.8 percent of participants had UICs >100, 50-99, 20-49 and <20 μg/l, respectively. Iodine contents of household salts were not adequate in the south of Tehran, indicating Tehranians in this region, previously iodine sufficient, now suffer from moderate iodine deficiency. These findings show necessity of more detailed surveys for iodine nutrition improvement and emphasize the importance of attention being paid to the risk of iodine deficiency recurrence in Iran.