Relationship between Iodine Content in Household Iodized Salt and Thyroid Volume Distribution in Children

Objective To assess the effect of different levels of salt iodine content on thyroid volume（ThV） distribution using data from the 1999, 2011, and 2014 Chinese national iodine deficiency disorder（IDD） surveys. Methods Probability proportion to size（PPS） sampling method was used to obtain a representative national sample of 34,547, 38,932, and 47,188 Chinese children aged 8-10 years in 1999, 2011, and 2014 Chinese national IDD surveys, respectively. The iodine content in household iodized salt and urinary iodine concentration were measured and thyroid ultrasound examination was performed. The data were analyzed by SAS software using histograms and box plots. The skewness and kurtosis were calculated for testing the normality of ThV. Results The median iodine content in household iodized salt dropped from 42.30 mg/kg in 1999 to 25.00 mg/kg in 2014. The median urinary iodine concentration of children aged 8-10 years decreased from 306.0 μg/L in 1999 to 197.9 μg/L in 2014. The median and interquartile range（IQR） of ThV in 1999, 2011, and 2014 surveys were 3.44 m L and 1.50 m L, 2.60 m L and 1.37 m L, 2.63 m L and 1.25 m L, respectively. The skewness and kurtosis of ThV distribution in 1999, 2011, and 2014 surveys were 1.34 and 5.84, 0.98 and 3.54, 1.27 and 5.49, respectively. Conclusion With reduced salt iodization levels, the median urinary iodine concentration and median ThV of children decreased significantly, and the symmetry of the ThV distribution improved.

Association of iodized salt with goiter prevalence in Chinese populations: a continuity analysis over time

Background: Iodine deficiency disorders(IDD) refer to diseases that are caused by insufficient iodine intake, and the best strategy to prevent IDD is the addition of iodine to dietary salt. Because iodine deficiency is a common cause of goiter, the prevalence as effectively controlled after the implementation of universal salt iodization(USI) in China. However, there is substantial controversy as to whether the incidence of thyroid disorders is related to iodized salt intake. Therefore, we aimed to clarify whether the risk of goiter can be promoted by USI.Methods: A longitudinal continuous study based on the national monitoring results of IDD in China was performed for 3 consecutive years. We recorded the following indicators of IDD from 31 provinces: goiter number, two degrees of goiter(the degree of goiter severity) and cretinism(three endemic diseases), iodized salt intake, median urinary iodine concentration(UIC), soil iodine content and coverage rates of iodized salt. One-way Analysis of Variance(ANOVA) and linear regression analyses examined the differences between the three groups and correlations, respectively. Data were collected from the Chinese national IDD surveillance data in 2011-2013, and the background values of Chinese soil elements were published in 1990.Results: A reference male's daily intake of maximum iodine was 378.9μg, 379.2μg and 366.9μg in 2011, 2012, and 2013, respectively. No statistical association between daily iodized salt intake and the three endemic diseases was observed in 2011-2013(P >0.05). No association was observed between daily iodized salt intake and the UIC of children in 2011(P>0.05). Linear regression revealed no significant correlation between the soil iodine content and three endemic diseases. The present study indicated no difference in the daily iodized salt intake in each province during three years(F=0.886, P=0.647). The coverage rate of iodized salt remained above 98.7%, and goiter rates were stable in 2011-2013.Conclusion: There was no significant association between iodized salt intake and the three endemic diseases, suggesting that the current nutrition level of iodized salt did not cause the high goiter prevalence.

Effects of Storage and Cooking on the lodine Content in lodized Salt and Study on Monitoring lodine Content in Iodized Salt

In order to ensure that the intake of iodine from iodized salt is adequate, the effects of cooking, storage and iedination on iodine content in iodized salt have been studied. For moni toring the analytical Performance, a qoality control exawhnation was also undertaken. The loss of iodine was greater when salt was stored in plastic bag than in glass bottle. The loss was greater in fortified salt stored at 37℃ and under 76% humidity than in that at 20 ~ 25℃ and under lower humidity. The retention of iodine varied with the kind of has and also was influenced by the water content of cooked food. In general, the retention of iodine during cooking varied considerably (from 36. 6% to 86. 1 % ). The iodine concentration in salts varied greater from 3.0 to 100.3 mg/kg in salt for markets, and from 0 to 90.0 mg/kg in salts for households. 48. 3 % of samples from markets were found to be in compliance with national standards (30 ~ 50 mg/kg), and 72.0% of samples from households were in compliance with national standartl (20 ~ 50 mg/kg). Analytical data collected from 8 of the cooperative laheratories foran analytical reference material showed a 95% codridence interval of the population mean for both precision and accuracy, falling within X± 2SD and passing quality control exdrination

Iodine Concentration of Iodized Salts Consumed in Harper

This study determined concentrations of iodine, consistent with WHO iodine fortification standards, in commercial edible salts mostly consumed in Harper. The following hypothesis was put forward in the research study;H1: the iodine content of the two brands of iodized salts is different from the WHO iodine fortification levels;H0: the iodine content of the two brands of iodized salts is not different from the WHO iodine fortification levels. The hypothesis was tested in MS Excel 2010 and 2016 via the T-Test function giving p-value = 0.1476 and p-value = 0.0395 indicative of no significant difference in the iodine concentration of the salts compared with the lower limit of WHO standard 20 mg·Kg-1 and huge contrast in the iodine concentration of the salts compared with the upper limit of WHO standard 40 mg·Kg-1 respectively. The UV spectrophotometric method was used to analyze and measure the iodine concentration in the twelve (12) samples of two different brands bought from grocery stores in Harper city. Results indicated that all samples of the two (2) brands of iodized salts contained iodine of no significant difference relative to the lower limit of WHO standard but far below the upper limit of the WHO standard. The study therefore recommends monitoring of commercial iodized salts by appropriate authorities in Harper to ascertain the WHO iodization fortification standards before reaching consumers.

Control of Iodine Deficiency Disorders Following 10-Year Universal Salt Iodization in Hebei Province of China

Objective To evaluate the effectiveness of universal salt iodization （USI） for the control of IDD in Hebei province since it was implemented in 1995, identify the problems currently encountered in the implementation of USI and provide practical proposals for addressing these problems. Methods Probability proportionate to size sampling （PPS） was employed in the surveillance of IDD, for which a total of 1200 school children aged 8-10 years were randomly selected from 30 counties around the whole province during each IDD survey. The iodine content of salt was determined quantitatively with the titration method. The iodine content of urinary samples was measured by the method of ammonium persulfate oxidation. Results The coverage of iodized salt increased from 65.0% in 1995 to 98.0% in 1999, then decreased to 88.1% in 2005 which was below the national standard of 90%. The median urinary iodine of children aged 8-10 years varied between 160.1 μg/L and 307.4 μg/L, which was above the national standard. The proportion of urinary samples with iodine content above 300 lag/L was over 30% in 2005, implying exorbitant iodine nutrition among the children. The goiter rate （TGR） among children aged 8-10 years dropped from 11.8% in 1995 to 2.7% in 2005, indicating that the spread of endemic goiter was under control. Conclusion Preliminary elimination of IDD was achieved by USI in Hebei province. Nevertheless, some problems still existed in USI such as non-iodized salt competition, over iodization and un-standardized iodization. In order to address these problems, the management and supervision of salt market needs to be strengthened to prevent non-iodized salt from reaching households; updating equipment and modifying techniques are also necessary to ensure the quality of iodized salt; to clarify the causes of excessive urinary iodine content, the various sources of iodine from the diet need to be investigated in the future.

Iodine Content of Processed Foods and Condiments Sampled in China, 2017-2019

Introduction: Facing the challenge of increasing consumption of processed foods in China, along with the demand for salt reduction, and dynamic adjustment of universal salt iodization (USI) policy, it is necessary to timely evaluate the distribution of iodine content in processed foods and condiments, so as to provide more accurate data for population dietary iodine intake assessment. Methods: From markets in 6 cities and e-commerce platforms, cereal, tuber, legume, meat, fish, egg, and dairy products, and condiments, consumed by volunteers who attended in iodine intake investigation, and top selling products in particular with well-noted brands were preferentially sampled during 2017 to 2019. After being mixed and homogenized, each sample was detected by ICP-MS method. The range and medium of iodine content in each type of product were given. Results: After merging samples with close value in the same style of the same brand, and screening out samples with no added salt or low sodium content (≤120 mg/100g), total 725 data were sub-grouped and analyzed. In comparison with the 95th percentile of the iodine distribution in relative nature source, assessed by our previous study, nearly 77% of products made from grains, potatoes, beans, nuts, livestock and poultry meat were presumed to be processed with iodized salt. In somewhat, related with sodium value marked on food labeling, the median iodine ranged from 1.1 mg/100g to 149 mg/100g. The variation of iodine in egg, milk and fish made products, and seaweed or with seaweed products was greatly affected by the background of ingredients, the median content most floated between 12.8 mg/100g and 86.8 mg/100g, even up to 1800 mg/100g in seasoned seaweed. Based on the frequency of iodine digital and the ratio of iodine to sodium, it was speculated that nearly 90% of soy sauce and 73.5% of other seasonings like vinegar, sauce, paste, etc., were not added iodized salt, with overall median iodine 4.0 mg/100g and 12 mg/100g respectively. Conclusion: Using iodized salt in processed foods is an approach of USI police. Affected by the nature backgrounds of ingredients composed, the amount of salt used, and the regulated fortification level, iodine content in each kind of product varied largely. It’s important to establish a monitoring system in processed foods, as well as fortification salt, to control the benefit and risk of iodine health.

Effect of universal salt iodization on antithyroid drugs

Iodine deficiency disease （IDD） is common in China. An universal salt iodization （USl） program has been implemented by the Chinese government since 1996. As a result, the goiter rate in 8- to 10-year old children decreased from 20.4% in 1995 to 5.8% in 2002.1 But the adverse effects of iodine excess such as iodine-induced hyperthyroidism, iodine-induced goiters, iodine-induced hypothyroidism, etc. have become a great concern to healthcare professionals as well as the general population. The impact of USI on antithyroid drugs （ATDs） might become a potential challenge to address. With a special grant from the Department of Disease Control, the Health Ministry of China, we conducted a prospective study on the effects of USI on ATDs at the thyroid section of the Endocrinology Clinic of Peking Union Medical College Hospital （PUMCH）, Beijing.