Iodine Content Of Salt Research Articles

Assessment of Iodine Status in Children, Adults, Pregnant Women and Lactating Women in Iodine-Replete Areas of China

BackgroundIodine deficiency disorders (IDD) are widespread in China. Presently, IDD have been put under control by Universal Salt Iodisation (USI) in China; however, there is a lack of evidence on whether the iodine status in adults, pregnant women and lactating women is optimal. This study was therefore conducted to assess the iodine nutrition and thyroid function of children, adults, pregnant women and lactating women residing in areas where the USI program is fully established.DesignSix areas were selected according to the geographical regions in China. In each of these areas, we selected 4 distinct groups of subjects (children, adults, pregnant women and lactating women) in regions where the coverage rate of iodised salt was more than 95% and the levels of iodine and fluoride in drinking water were less than or equal to 10 µg/L and 1 mg/L, respectively. We tested the iodine content of salt, urinary iodine (UI), free thyroxin (FT4), thyrotropin (TSH), thyroglobulin (Tg), thyroglobulin antibody (Tg-Ab) and antimicrosomal antibody (TM-Ab) in the 4 groups, and examined the thyroid volume in children. ResultsThe median urinary iodine (MUI) concentrations were 271.4 μg/L, 260.2 μg/L, 205.9 μg/L and 193.9 μg/L in children, adults, pregnant women and lactating women, respectively; MUI in children and adults were more than adequate. The goitre prevalence (GP) in children was 6.70%. The odds ratios (OR) of subclinical hypothyroidism in the Tg-Ab- or TM-Ab-positive groups were 3.80, 7.65, 2.01 and 7.47 for children, adults, pregnant women and lactating women, respectively, compared with the negative groups. ConclusionsThe iodine status in children and adults is above the requirement, we should reduce their iodine intake. Subclinical hypothyroidism easily occurs in the Tg-Ab or TM-Ab positive groups.

Iodine nutritional status and risk factors for goitre among schoolchildren in South Tajikistan.

BackgroundIodine deficiency affects nearly 1.9 billion people worldwide, but it can be prevented by salt iodization. This cross-sectional survey assessed current iodine status, iodized salt coverage and risk factors for goitre among schoolchildren in South Tajikistan.MethodsTen primary schools in four districts in South Tajikistan were randomly selected. In schoolchildren aged 7 to 11 years, a spot urine sample was collected for measurement of urinary iodine, dried blood spots were collected for measurement of thyroglobulin, and goitre was assessed by palpation. Iodine content of salt samples and local selling points was determined by coloration using rapid test kits and titration method.ResultsOf 623 schoolchildren enrolled, complete data was obtained from 589. The overall median urinary iodine concentration (UIC) was 51.2 μg/L indicating mild-to-moderate iodine deficiency. Among all children, 46.6% (95% Confidence Interval (CI) = 42.4%-50.6%) of children were found to be goitrous (grade 1 goitre: 30.6%, 95% CI = 26.9%-34.5%; grade 2 goitre: 16.0%, 95% CI = 13.1%-19.2%). The risk factor for goitre remaining significant in the multivariable logistic regression model was 'buying salt once a month’ (OR = 2.89, 95% CI = 1.01-8.22) and 'buying salt once every six months’ (OR = 2.26, 95% CI = 1.01-5.04) compared to 'buying salt every one or two weeks’. The overall median thyroglobulin concentration was elevated at 13.9 μg/L. Of the salt samples from households and selling points, one third were adequately iodised, one third insufficiently and one third were not iodised.ConclusionIodine deficiency remains a serious health issue among children in southern Tajikistan. There is a persisting high prevalence of goitre, elevated thyroglobulin and low UIC despite interventions implemented by Tajikistan and international partners. Quality control of salt iodine content needs to be improved. Continued efforts to raise awareness of the health effects of iodine deficiency are needed to increase consumer demand for iodised salt.

A Review on Iodine Determination Methods in Salt and Biological Samples

Context: Iodine is an essential micronutrient, particularly because of its role in the structure of the thyroid hormone. Many people live in iodine deficient regions of the world, and hence need dietary iodine supplement. Though, iodine analysis of biological samples, especially urine, is a method for the evaluation of iodine status in consumers. This paper presents a review of the most common methods used to determine iodine levels in salt and biological samples. Evidence Acquisitions: We conducted a literature review of published English articles in various parts of the world using databases from PubMed, World Health Organization between 1934 and 2012. Results: A total of 2030 articles were identified and after eligibility criteria based evaluation, 63 articles were included in this literature review. The titration method is the most commonly used method for quantitative evaluation. The two main methods used to determine iodine levels in urine and milk are as follows: The instrumental method and the colorimetric methods in association with Sandell and Kolthoff reaction. Conclusions: Despite the high risk of bias of many included studies, the results suggested the Sandell and Kolthoff reaction methods to determine iodine in milk and urine, methods are now technically very simple and have been used by many laboratories to measure iodine levels for many years. The titration method remains the reference method to determine iodine concentrations in salt. Other methods should be standardized against the titration method. Dried whole blood spots Triglycerides (TG) and thyroid stimulating hormone (TSH) are sensitive indicators of iodine deficiency.

A comparative study of prevalence of thyroid nodules in children with that in adults

[Summary] With populational proportional sampling (PPS) method in Baiguo village,one central primary sehool was selected,and villagers aged 20-80 in nearly village were chosen as control.Cross-seetional survey methodology was employed,B-type ultrasonography was used to determine thyroid volume and nodule of ebildren.Arsenic cerium catalytic spectrophotonetric assay was employed to detect urinary iodine.A direct titration measurement was used to determinate iodine content in salt.180 children aged 6-12 were surveyed,2 cases of goiter were found (1.11％).16 cases of thyroid nodules were discovered(8.89％),including 3 boys(3.45％,n =87) and 13 girls(13.98％,n =93).Girls had a higher prevalence than boys (x2 =6.154,P =0.015).The prevalence of thyroid nodules in that village was 24.51％,being statistically significant between 2 groups (x2 =17.368,P =0.001),and increasing with the age. Key words: Iodine; Goiter; Thyroid nodules; Urinary iodine; Iodized salt; Children; Adults; Epidemiologieal studies

To Estimate the Effect of Relationship of Salt Iodine Level and Prevalence of Goiter Among Women of Reproductive Age Group (15–49 Years)

The present study is a Cross-Sectional Study and was conducted in Post-graduate department of Community Medicine, Govt. Medical College, Srinagar between Feb. 2012 and Jan. 2013. The sample size of 1,041 was estimated. The study was conducted to estimate the effect of relationship of salt iodine level and prevalence of goiter among women of reproductive age group in two districts of Kashmir valley, district Srinagar and district Ganderbal, which were selected randomly. A frame of the blocks and villages in the two districts and their population was formed. From each district 10% of the blocks were selected using simple random sampling. From each block, 5% of the villages were selected using simple random sampling. A door to door survey was conducted in the selected villages and all the women in the reproductive age group (15-49 years) identified and examined clinically for goiter after taking informed consent. Salt samples (one teaspoonful) from every household were taken and assessed for iodine content on spot and the iodine content of salt was assessed qualitatively by spot testing kits. The results of the present study have indicated that iodine deficiency continues to be a health problem. Almost the whole population consumes powdered salt but the storage and cooking practices diminish the iodine content of salt and results in decreased intake. Thus the need of the hour is to make people aware about proper storage and cooking practices. Women in the reproductive age group especially need to be made aware about the importance of consumption of adequately iodized salt because of the wide range of ill effects of iodine deficiency on the developing fetus and the growing child. In addition monitoring of iodine content of salt at distributor level should be done.

Iodine Nutrition Status and Knowledge, Attitude, and Behavior in Tehranian Women Following 2 Decades Without Public Education

To evaluate the association of iodine nutrition status and knowledge, attitude, and behavior in Tehranian women after 2 decades without updating public education. Cross-sectional study. Eight health care centers from 4 district areas of Tehran. A total of 383 women aged ≥ 19 years, randomly selected. Iodine concentration of 24-hour urine samples, iodine content of household salts, and knowledge, attitude, and practice scores regarding iodine nutrition and iodized salt. Multiple logistic regression was used to identify the association of knowledge, attitude, and practice scores with urinary iodine concentration (UIC) < 100 μg/L. The percentages of Tehranian women with high knowledge, attitude, and practice scores were26%, 26%, and 14%, respectively. Practice score was significantly different between females withUIC < 100 and > 100 μg/L (P = .001). Risk of UIC < 100 μg/L in women of childbearing age (19-45 years) after adjustment of education level, region of residence, and iodine content of salt was significantly associated with intermediate practice score (odds ratio = 2.6; 95% confidence interval, 1.3-13.2). Marginally suboptimal iodine status in women of childbearing age can be attributed to inappropriate practices, but not to knowledge and attitude.

Iodine Content of Household Salt and Urinary Iodine of Primary School Pupils in Commercial Towns in Nsukka Senatorial Zone, Enugu State, Nigeria

Iodine Content of Household Salt and Urinary Iodine of Primary School Pupils in Commercial Towns in Nsukka Senatorial Zone, Enugu State, Nigeria

Excess iodinuria in infants and its relation to the iodine in maternal milk

ObjectiveIodine is an essential micro nutrient, and a deficiency or excessive intake of this mineral is related to changes in thyroid function. In Brazil, both deficiency and excessive intake of iodine are common; however, excessive intakes have recently been observed. Thus, the objective of the present study was to assess the iodine concentration in maternal milk, taking into account the salt iodine concentration of the participating households and in the infants’ urine. MethodUrine samples from 33 infants (less than 6 months of age), maternal milk samples and samples of the kitchen salt used by the mothers were collected. The iodine levels in the urine and maternal milk were assessed by ICP-MS; the iodine levels in the salt were assessed by titration. ResultThe median iodinuria value in the infants was 293μg/L; the mean iodine concentration was 206μg/L in the maternal milk and 39.9mg I/kg in the salt. There was a positive correlation between the iodine concentration in the maternal milk and the infant iodinuria value. ConclusionThe median infant iodinuria was elevated due to the high iodine concentration present in the maternal milk. High iodine values were caused by high salt iodine levels, which should be reduced.

Household Salt Iodine Content Estimation with the Use of Rapid Test Kits and Iodometric Titration Methods

Universal salt iodization remains the best strategy for controlling iodine deficiency disorders in Nepal. This study was designed to study the salt types and the household salt iodine content of school aged children in the hilly and the plain districts of eastern Nepal. This cross-sectional study was carried out on school children of seven randomly chosen schools from four districts, namely, Sunsari, Dhankuta, Sankhuwasabha and Tehrathum of eastern Nepal. The school children were requested to bring two teaspoonfuls (approx. 12-15 g) of the salt which was consumed in their households, in a tightly sealed plastic pouch. The salt types were categorized, and the salt iodine content was estimated by using rapid test kits and iodometric titrations. The association of the salt iodine content of the different districts were tested by using the Chi-square test. The sensitivity, specificity, positive predictive values, and negative predictive values of the rapid test kits were compared with the iodometric titrations. Our study showed that mean±SD values of the salt iodine content in the four districts, namely, Sunsari, Dhankuta, Sankhuwasabha and Tehrathum were 34.2±17.9, 33.2±14.5, 27.4±15.1 and 48.4±15.6 parts per million (ppm). There were 270 (38.2%) households which consumed crystal salt and 437(61.8%) of the households consumed packet salts. Our study recommends a regular monitoring of the salt iodization programs in these regions. More families should be made aware of the need to ensure that each individual consumes iodized salt.

Validation of a User-Friendly and Rapid Method for Quantifying Iodine Content of Salt

Despite considerable progress made in the past decade through salt iodization programs, over 2 billion people worldwide still have inadequate iodine intake, with devastating consequences for brain development and intellectual capacity. To optimize these programs with regard to salt iodine content, careful monitoring of salt iodine content is essential, but few methods are available to quantitatively measure iodine concentration in a simple, fast, and safe way. We have validated a newly developed device that quantitatively measures the content of potassium iodate in salt in a simple, safe, and rapid way. The linearity, determination and detection limit, and inter- and intra-assay variability of this colorimetric method were assessed and the method was compared with iodometric titration, using salt samples from several countries. Linearity of analysis ranged from 5 to 75 mg/kg iodine, with 1 mg/kg being the determination limit; the intra- and interassay imprecision was 0.9%, 0.5%, and 0.7% and 1.5%, 1.7%, and 2.5% for salt samples with iodine contents of 17, 30, and 55 mg/kg, respectively; the interoperator imprecision for the same samples was 1.2%, 4.9%, and 4.7%, respectively. Comparison with the iodometric method showed high agreement between the methods (R2 = 0.978; limits of agreement, -10.5 to 10.0 mg/kg). The device offers a field- and user-friendly solution to quantifying potassium iodate salt content reliably. For countries that use potassium iodide in salt iodization programs, further validation is required.

Evaluation of Iodine Content in Table Salt Consumed in Democratic Republic of Congo

DR Congo has adopted universal salt iodization to reduce disorders due to iodine deficiency. Since 1994, only iodized salt can be imported, but there is currently no routine monitoring of the iodine content of distributed salt. It is therefore unclear if iodine deficiency remains a health problem, particularly in pregnant women. To evaluate the iodine content of salt in households of pregnant women in Lubumbashi. We conducted a survey of the iodine content of salt consumed by 375 women presenting at prenatal consultations in three socially different areas of Lubumbashi: urban, semiurban, and rural. The women were questioned about where they purchased salt, how it was packaged, and how they stored the salt, and each woman provided a sample of salt for determination of its iodine content by the iodometric method. Most women (84.3%) bought salt in the public markets, mainly in bulk (93.6%); 80.0% stored salt in plastic boxes. The median iodine content was 27.5 ppm (IQR, 16.0-38.1) in urban areas, 19.0 ppm (IQR, 7.4-31.7) in semiurban areas, and 20.1 ppm (IQR, 5.3-31.7) in rural areas. The iodine content was less than 15 ppm (minimum threshold) in 36.3% of samples, including 13.9% without any detectable iodine. The iodine content was above 40 ppm (maximum limit) in 18.9% of samples. Only 44.8% of salt samples had adequate iodine content. The population of Lubumbashi remain at risk for hypothyroidism and hyperthyroidism. A effective and regular system for the control of iodin content in distributed salt is needed in DR Congo.

Iodine Nutrition and the Prevalence of Thyroid Disease after Salt Iodization: A Cross-Sectional Survey in Shanghai, a Coastal Area in China

BackgroundBoth insufficient and excess iodine may produce thyroid disease. After salt iodization in China, the median urine iodine concentration (UIC) of children aged 8–10 years appeared adequate. However, it is unknown whether dietary changes due to rapid economic development in Shanghai have affected whole population iodine nutrition.ObjectiveTo assess dietary iodine intake, UIC and the prevalence of thyroid disease in the general population of Shanghai.DesignA cross-sectional survey was conducted with general participants aged 5–69 years (n = 7,904) plus pregnant and lactating women (n = 380 each) selected by stratified multistage sampling. The iodine concentrations in their salt, drinking water and urine were measured. Daily iodine intake was estimated using the total diet study approach. Serum thyroid hormone concentrations and thyroid-related antibodies were measured and thyroid ultrasonography was performed.ResultsThe median iodine concentration in salt was 29.5 mg/kg, and 12.8 µg/L in drinking water. Iodized salt, used by 95.3% of participants, contributed 63.5% of total dietary iodine. Estimated daily iodine intake was 225.96 µg. The median UIC of general participants was 146.7 µg/L; UIC <100 µg/L (iodine insufficiency) was seen in 28.6%; UIC >300 µg/L (iodine excess) in 10.1%. Pregnant women had a median UIC of 135.9 µg/L, with UIC <150 µg/L in 55.4%. Thyroid nodules and subclinical hypothyroidism were found in 27.44% and 9.17%, respectively.ConclusionsAccording to published criteria, the current dietary iodine intake in Shanghai was generally sufficient and safe, but insufficient in pregnant women. Thyroid nodules and subclinical hypothyroidism were the commonest thyroid diseases identified.

Does a text messaging intervention improve knowledge, attitudes and practice regarding iodine deficiency and iodized salt consumption?

To determine the effectiveness of implementation of a prevention programme via mobile phone text messaging in enhancing knowledge, attitudes and practice concerning iodine deficiency and iodized salt consumption. In a randomized controlled trial, participants were subjected to a brief tele-educational support regarding iodine deficiency and the importance of iodized salt consumption. The intervention group received daily text messages via mobile phone for 6 weeks. Knowledge, attitude and practice scores, urinary iodine concentration and salt iodine content were assessed at baseline and 8 weeks after the intervention. Participants were recruited from health-care centres in Tehran, the capital city of Iran. For the present study 205 females aged ≥18 years were randomly assigned to the intervention (n 95) and control (n 110) groups. A significant difference was found in median knowledge scores between the intervention and control groups at follow-up (P = 0.004). There was also a significant difference in median attitude scores between the intervention and control groups (P = 0.02). The intervention group did not differ significantly in median practice score, urinary iodine concentration and salt iodine content from the control group. Text messaging interventions are effective in improving individuals' knowledge and attitudes regarding preventive health-care topics.

Sodium reduction and the correction of iodine intake in Belgium: Policy options

Many studies suggest that high salt intakes are related to high blood pressure and consequently cardiovascular diseases. In addition salt intake was found to be related with obesity, renal stones, osteoporosis and stomach cancer. Belgium, such as other European countries, is suffering from both salt intakes that are twice as high as the recommended intakes and mild iodine deficiency. No comprehensive strategy encompassing both public health problems has been developed. While specific salt reduction targets for processed foods are still under discussion using a consensus approach with industry, an agreement was signed between the bakery sector and the Ministry of Health in April 2009, to encourage and increase the use of iodised salt in the production of bread. Based on results of recent surveys on population iodine status it is advised not to currently revise iodine concentrations in salt in bread but to advocate for a higher percentage of bakers using iodised salt and to install a good monitoring system to control the percentage of bakers effectively using adequately iodised salt. With regard to salt reduction, it is of utmost importance that all companies contribute and harmonise the salt content of their products according to the lowest possible thresholds in a first step. In order to achieve this goal, it will be necessary, in addition to the consensus approach, to come up with at least some legislative tools such as a salt tax or mandatory labelling of foods exceeding a specific sodium concentration. Once salt reduction targets have been clearly defined in Belgium over the longer term, a legal framework should be set in place where iodine concentration in salt for the production of bread and household salt is strictly regulated by law, to avoid a large variability in the iodine content of salt brands consumed. In conclusion, it is possible to tackle salt reduction and iodine deficiency at the same time on the condition that the approach is coordinated and well monitored. All the interventions and measures taken should clearly include education and communication directed towards consumers, food producers, public health professionals, pharmacists, healthcare workers, and media representatives.

Iodine status and fish intake of Sudanese schoolchildren living in the Red Sea and White Nile regions.

To investigate iodine status and fish consumption of schoolchildren living in the Red Sea and White Nile regions of Sudan. Cross-sectional study to determine urinary iodine concentration, visible goitre rate, iodine content of salt and fish consumption. Port Sudan (Red Sea) and Jabal Awliya (White Nile), Sudan. Two hundred eighty (n 280) children aged 6-12 years (142 boys, 138 girls). The median urinary iodine concentration in children from Port Sudan and Jabal Awliya was 553 and 160 μg/l, respectively. Goitre was detected in 17.1 % of children from Port Sudan but only in 1.4 % from Jabal Awliya, The salt samples from Port Sudan contained 150-360 mg iodine (KOI3)/kg salt, whereas those from Jabal Awliya had levels below the detection limit. Despite consuming salt devoid of iodine, children from Jabal Awliya had optimal iodine status. It is plausible that consumption of Nile fish from Jabal Awliya Reservoir, which is a good source of iodine and favoured by the locals, might have provided sufficient iodine. In contrast, children from Port Sudan were at higher risk of iodine-induced hyperthyroidism resulting from consumption of excessively iodised salt. The findings of the study clearly demonstrated that (i) Sudan still has a problem with iodine nutrition and quality control and monitoring of salt iodisation and (ii) including fish in the diet could provide a sufficient amount of iodine for schoolchildren.

Результаты эпидемиологических исследований распространенности йододефицитных заболеваний в Ферганской области Республики Узбекистан

Несмотря на проводимые мероприятия, направленные на ликвидацию йодной недостаточности, Республика Узбекистан остается зоной высокой распространенности йододефицитных заболеваний (ЙДЗ). В результате проведенных эпидемиологических исследований выяснено, что распространенность эндемического зоба среди детей в стране составляла 71 % в 1998 г. и 63 % в 2004 г. Динамика снижения йодного дефицита была связана с активной работой по ликвидации йододефицитных заболеваний — это обеспечение йодирующими установками и йодатом калия соледобывающих и солеперерабатывающих предприятий, проведение широкомасштабных санитарно-просветительских мероприятий среди различных слоев населения, на государственных предприятиях и в частном секторе, проведение регулярного мониторинга содержания йода в соли и моче. В мае 2007 г. был принят Закон РУз «О профилактике йододефицитных заболеваний». В настоящей работе приводится анализ ЙДЗ в Ферганской области согласно рекомендациям ВОЗ. Выявлено, что распространенность эндемического зоба снизилась до 39,9 % в 2010 году. Таким образом, выяснено, что распространенность ЙДЗ в Ферганской области в динамике снижается, хотя и остается довольно высокой.

Eighteen Years of Continuously Sustained Elimination of Iodine Deficiency in the Islamic Republic of Iran: The Vitality of Periodic Monitoring

Two decades ago the Islamic Republic of Iran was among countries most severely affected by iodine deficiency. Iran has since achieved great success in the control and elimination of iodine deficiency disorders (IDDs) following the national salt iodization program, initiated in 1989. The aim of the study was to evaluate the effectiveness of sustained consumption of iodized salt by Iranian households and the current status of iodine nutrition in all 30 provinces of Iran. Goiters-measured by palpation-and urinary iodine concentration of children were assessed. In this descriptive cross-sectional study, 36,000 schoolchildren (18,000 girls and 18,000 boys), aged 8-10 years, were randomly selected, from October 2007 to February 2008, from 30 provinces of the country. Goiter prevalence and urinary iodine excretion in schoolchildren and the iodine content of salt at household, factory, and distribution site levels were measured. The goiter rate in the country was 6.5% (6% grade 1 and 0.5% grade 2), and the weighted goiter rate was 5.7%. The total goiter rate in Hamedan, Zanjan, Kermanshah, Mazandaran, and Gilan provinces was over 10%. The median urinary iodine was 140 μg/L. Urinary iodine levels of 20-50, 50-99, and ≥100 μg/L were noted in 15.3%, 19.8%, and 64.9% of the samples, respectively. In four provinces, the median urinary iodine was lower than 100 μg/L. The mean (±SD) and median salt iodine values were 23.2 (±13.8) and 34.7 ppm, respectively, at the production level, and 32.4 (±14.7) and 32.3 ppm, respectively, at the distribution level. Ninety-eight percent of households consumed iodized salt, 58% of households had appropriate salt storage, and 27% of the household salts contained <20 ppm. Iran has achieved much in the development of universal salt iodization strategy and elimination of IDDs and currently meets all criteria for sustainable elimination of iodine deficiency. However, the lack of adequate iodine nutrition in some provinces necessitates special attention and proper monitoring.

Excessive iodine intake during pregnancy in Somali refugees.

Iodine deficiency and excess are both associated with adverse health consequences, with fetuses, children and pregnant women being most vulnerable to the devastating effects of severe deficiency. It is often assumed that the iodine status of a population if displaced or in a remote or emergency situation is low. However, there is little evidence available to support this assumption, especially among long-term food-aid-dependent pregnant women. An effectiveness trial of a prenatal multiple-micronutrient supplement that contained 150 µg day(-1) iodine was conducted in two refugee camps in the North Eastern Province of Kenya in 2002. Urinary iodine concentration (UIC) was measured in a subsample of pregnant women attending antenatal care in Dagahaley (control camp) (n = 74) and Ifo (intervention camp) (n = 63). There was no significant difference in median UIC between the two camps (P = 0.118). The combined median UIC was 730 µg L(-1) (interquartile range, 780) (5.77 µmol L(-1)) and exceeded the upper safe limit of 500 µg L(-1) (3.95 µmol L(-1)) for pregnant women (P < 0.001), indicating excessive iodine intake. About 20% of the study subjects had 'more than adequate' urinary iodine, while over 71% had excessive UIC. Salt iodine content varied between 5.1 and 80.1 ppm in the five market salt samples analysed. In conclusion, excessive iodine intake was evident in the Dadaab refugee camps. Further research needs to be conducted to investigate the source of excess iodine, to determine the measures needed to address excessive iodine intake and to reconsider the World Health Organization/World Food Programme/United Nations Children's Fund guidance on supplementation of vulnerable groups in emergencies.

Iodine excess or not: analysis on the necessity of reducing the iodine content in edible salt based on the national monitoring results.

Using national monitoring data collected between 1995 and 2009, this paper describes the change in trend with regard to the coverage of qualified iodized household salt and iodine status of the population in China since the implementation of universal salt iodization. The review indicates that the iodine content in edible salt increased from 16.2 mg/kg in 1995 to 42.3 mg/kg in 1999, then declined to 30.8 mg/kg in 2005 and has retained this level through the most recent data collection cycle, which is considered sufficient to achieve optimal iodine status. However, the median urinary iodine excretion level for children aged 8-10 at the national level has been consistently classified as "excessive iodine intake" since 1997, suggesting that although three adjustments on the standard of iodine content in edible salt have been made, the current content of salt iodization is still on the high side. The iodine content in edible salt could be lowered, and possibly adapted to local specific conditions such as water iodine content and the average daily intake of salt among the population in order to achieve a balance between preventing deficiency and reducing the risk of excessive intake.

A Multicentric Study on Validation of Spot Testing Kit

To assess the validity of the Spot testing kit (against the Standard iodometric titration) in the semi-quantitative estimation of iodine in salt. The project was conducted at four centers in the country, namely, Vadodara, Jodhpur, Dibrugarh and New Delhi (AIIMS, coordinating centre). Uniform protocol was utilized at all the four centres. The school going children were asked to bring 30 g of iodine from their kitchen in an auto-seal polythene pouche with an identification slip. The iodine content of 3,010 salt samples (more than 700 salt samples from each center) was estimated independently by two different methods i.e., Iodometric Titration (used as reference standard) and Spot Testing Kit (STK) method, and the results were compared. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of the STK method in relation to the Standard iodometric titration (SIT) were calculated. From total of 3,010 salt samples, majority (98%) of the salt samples collected were of powdered salt. The specificity of various research centers ranged from 60.5% to 88.9%. The positive predictive value of the various research centers ranged from 69.9% to 98%. The NPV of the various research centers ranged from 96.8% to 100%. The pooled sensitivity and specificity of the STK method (against IT method) for four centers together was 99.6% and 66.7%, respectively. The STK method is reliable for semi quantitative estimation of iodine content in salt and it can be used for monitoring the quality of iodized salt available in the community.