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Background and Objectives: WHO recommended that iodized salt are more than 90% of households in USI programs, which may not be suitable for all regions, especially in coastal areas. This study intended to find out levels of iodine nutrition and give advice from the USI programs for areas with different iodized salt coverage., Methods and Study Design: Coastal and inland areas were selected according to geographical regions in Zhejiang Province, China. The water iodine concentration (spectrophotometer analysis), salt iodine concentration (the colorimetric titration method), salt intake, urinary iodine concentration (spectrophotometer analysis), and thyroid volume examination (ultrasonography), as well as questionnaire, were measured in the two areas., Results: Mean Urinary Iodine concentration (MUIs) of children in coastal areas was 149 μg/L, which was significantly lower than that in inland areas (191 μg/L). MUIs of pregnant women in coastal and inland areas were111 and 138 μg/L, respectively. Pregnant women who consumed iodine-containing supplements had higher MUIs (207 μg/L) than those did not (134 μg/L) in inland areas. Prevalence of goitre in children reached 7.0% and 6.6% in coastal and inland areas, respectively. The lowest prevalence of goitre was reached when the urinary iodine concentration was approximately 120-160 μg/L in coastal areas., Conclusion: Iodine levels of coastal and inland areas were in the adequate range. Advice from the USI program should be specialized for different areas to appropriately reduce the salt iodine concentrations in inland areas and to determine an appropriate proportion of households using iodized salt in coastal areas. Moreover, iodine supplement intake during pregnancy should officially be recommended.

Objective: To assess the level of dietary iodine intake and its contribution in Zhejiang., Methods: A total of 9798 subjects were recruited in this survey with multi-stage stratified cluster random sampling method in April, 2010, the 24-hours dietary recall method and the "food composition table" were used to obtain the dietary iodine intake, and edible salt and drinking water samples were collected to detect the content of iodine., Results: A total of 9798 subjects were included in this survey. The mean intake of dietary iodine in Zhejiang residents per standard man-days was (395.13 ± 78.16) µg/d, which in between of Recommended Nutrient Intake (RNI) 150 µg/d and Tolerable Upper Intake Level (UL) 1000 µg/d; the iodine intake of 18.40% (1803/9798) subjects was lower than estimated average requirement of iodine (EAR), 4.68% (459/9798) subjects was higher than the UL. The means of dietary iodine intake in various areas were (498.85 ± 96.77) µg/d, (384.50 ± 88.76) µg/d and (326.33 ± 78.32)µg/d in inland areas, sub-coastal areas and coastal areas, successively (F = 27.17, P < 0.05); the proportions of dietary iodine intake lower than EAR were 34.89% (1239/3551), 10.48% (370/3530) and 7.14% (197/2717) in coastal areas, sub-coastal area and inland areas, successively (χ(2) = 62.87, P < 0.01) , while those higher than UL were 5.10% (180/3530), 4.86% (132/2717) and 4.14% (147/3551) in sub-coastal area, inland areas and coastal areas.In the condition of ignoring cooking loss, the mean contribution of dietary iodine intake in edible salt, all kinds of food and drinking water were 74.92% (296.03/395.13), 23.85% (94.24/395.13) and 1.23% (4.86/395.13), successively; the contributions of edible salt in inland areas, sub-coastal areas and coastal areas were 83.72% (417.64/498.85), 73.05% (280.88/384.50) and 66.83% (280.09/326.33), successively; the contributions of drinking water in sub-coastal areas, coastal areas and inland areas were 1.61% (6.19/384.50) , 1.44% (4.70/326.33) and 0.65% (3.24/498.85) , successively (χ(2) = 7.24, P = 0.032) ; the contribution of laver in coastal areas, sub-coastal areas and inland areas were 22.57% (73.65/326.33), 17.11% (65.79/384.50) and 8.09% (40.36/498.85), successively (χ(2) = 82.17, P < 0.01) ; the contribution of sea fish in coastal areas, sub-coastal areas and inland areas were 2.38% (7.77/326.33), 0.72% (2.77/384.50) and 0.68% (3.39/498.85) (χ(2) = 19.47, P = 0.012)., Conclusions: The dietary iodine intake of Zhejiang residents was at recommended intake levels; the iodized salt turns out to be the main source, the iodine nutrition level was relatively low in coastal areas of Zhejiang, which the coverage of iodized salt should be improved.

Objective: To evaluate the iodine nutrition level of population in Zhejiang province and to analyze the relevant influencing factors from 2009 to 2011., Methods: From October 2009 to October 2011, a total of 19 517 subjects were recruited in this cross sectional survey, by multistage stratified cluster random sampling method. The subjects were all living over three years in Zhejiang province. The basic information and life styles were interviewed by questionnaires; and the samples of drinking water, edible salt and urines were separately collected from the subjects to test the content of iodine. In total, 16 228 subjects answered the questionnaire, and 265 samples of drinking water, 7811 samples of edible salt and 19 517 samples of urine were collected. Then, we analyzed the distribution of iodine in water, edible salt and urine samples, as well as the relevance., Results: The median (25% - 75% percentile) of water iodine was 2.42 (1.17 - 6.28) µg/L in drinking water among Zhejiang residents; while separately 2.79 (1.60 - 6.87) µg/L in city and 2.04 (1.03 - 5.29) µg/L in country side (Z = 2.07, P < 0.05). The figures turned out to be 2.17 (1.22 - 5.73) µg/L, 2.77 (1.88 - 6.87) µg/L, and 1.40 (0.77 - 5.65) µg/L, respectively, in coastal areas, coastal periphery areas and inland areas (χ(2) = 11.16, P < 0.05). The median (25% - 75% percentile) of salt iodine was 28.80 (22.93 - 32.40) mg/kg; while separately 29.00 (24.50 - 32.60) mg/kg and 28.50 (13.90 - 32.29) mg/kg in city and country side (Z = 6.32, P < 0.05). The figures turned out to be 25.19 (0.00 - 30.20) mg/kg, 29.00 (26.60 - 31.70) mg/kg and 32.40 (28.94 - 36.30) mg/kg, respectively, in coastal areas, coastal periphery areas and inland areas (χ(2) = 1581.62, P < 0.05). The coverage rate of iodized salt was 79.54% (6213/7811) in all province. The urinary iodine median was 160.74(97.20 - 247.00) µg/L, while the urinary iodine median in pregnant women was 137.99 (82.40 - 215.30) µg/L, lower than the recommended optimal levels, which was 150 - 249 µg/L. The figures turned out to be 153.45(92.00 - 237.50) µg/L in city and 168.00 (102.18 - 257.00) µg/L in country side (Z = -9.25, P < 0.05); while in coastal, coastal periphery place and inland areas, the median were separately 156.00 (94.29 - 242.80) µg/L, 150.14 (94.70 - 227.00) µg/L and 187.70 (109.00 - 276.80) µg/L (χ(2) = 194.12, P < 0.05). The analysis of relevance between urine iodine, water iodine and iodized salt showed that the urine iodine would increase as long as the iodized salt increased; and the difference had statistical significance (χ(2) = 440.88, P < 0.01). And there were no relevance between urine iodine level and the water iodine level (χ(2)cmh = 0.57, P = 0.45). The analysis of the influencing factors showed that education background (χ(2) = 14.17, P < 0.05), different styles of career (χ(2) = 16.15, P < 0.01) and diet habits (χ(2) = 108.63, P < 0.01) could influence the level of urine iodine., Conclusion: Iodine was deficient in Zhejiang province. The nutrition level of iodine was fine in Zhejiang in 2009, however, the coverage rate of iodine was commonly low in coastal areas, especially the pregnant women suffered from iodine deficiency. In our study, the factors influencing the urine iodine level included iodized salt, age, education background and diet habits.