Household Salt Storage and Seasoning Consumption Are Predictors of Insufficient Iodine Status Among Pregnant Women in Southeastern Brazil

Iodine deficiency in pregnancy may lead to adverse maternal and fetal outcomes, including impaired child development. Sociodemographic factors and different dietary habits may be related to iodine status in pregnant women. The aim of this study was to evaluate the iodine status and its predictors among pregnant women in a city of Southeastern Brazil. This cross-sectional study was conducted with 266 pregnant women receiving prenatal care in 8 primary health care units. Sociodemographic, obstetric and health, habits of acquisition, storage and consumption of iodized salt, and dietary iodine intake data were collected through a questionnaire. The iodine content was evaluated in urinary iodine concentration (UIC), household salt and seasonings, and drinking water samples. Pregnant women were categorized into three groups according to the UIC, determined by iodine coupled plasma-mass spectrometry (ICP-MS): insufficient (< 150 μg/L), adequate (150-249 μg/L), and more than adequate iodine nutrition (≥ 250 μg/L). The median (p25-p75) UIC was 180.2 μg/L (112.8-262.7). It was found 38% and 27.8% of insufficient and more than adequate iodine nutrition, respectively. Number of gestations, KI content of supplement, alcohol consumption, salt storage, and frequency of using industrialized seasoning were associated to iodine status. Alcohol consumption (OR = 6.59; 95%CI 1.24-34.87), pack the salt in opened container (OR = 0.22; 95%CI 0.08-0.57), and use industrialized seasoning weekly (OR = 3.68; 95% CI 1.12-12.11) were predictors of iodine insufficiency. The pregnant women evaluated have adequate iodine nutrition. Household salt storage and seasoning consumption were risk factors for insufficient iodine status.

Awareness, practices and perspectives on ensuring access to ideally packaged iodized salt in Nigeria

Salt iodization is a positive exemplar of a sustainable public-private partnership in promoting better nutrition outcomes in many countries. However, the gains in the past decades are gradually being eroded, following laxity in policy implementation, monitoring and regulatory roles resulting in increasing access to non-labelled salt in the Nigerian market. This study was designed to evaluate the awareness, practices and perspectives on salt iodization and regulations among salt marketers and consumers in Ibadan, Oyo state. This mixed-method study was carried out in seven major markets across Ibadan metropolis. A three-stage sampling technique was used to select 77 salt users/clients, 103 salt vendors, 12 salt wholesalers and four regulators/producers. Interviewer-administered questionnaire was used to collect information on types/brands of salt, handling, retail practices, awareness, and salt purchase preference. Structured in-depth interview was used to elicit information on existing regulations, compliance level, and monitoring activities. Descriptive statistics were used to analyse quantitative data. Interviews were tape-recorded, transcribed verbatim and analyzed thematically. Males constituted 66.7%, 1.0% and 14.3% of respondents among wholesalers, retail vendors, and clients, respectively, with 100.0%, 58.3% and 84.4% having at least primary education. All wholesalers and 30.1% of retail vendors used shaded structure. About 67% of the wholesalers and 58.3% of the retailers sold branded salt. Clients' basis for the use of non-branded salt included cheapness and greater quantity (54.5%), higher intensiveness/saltiness and greater quantity (22.1%), and cheaper cost (18.2%). Only 3% of the consumers were aware of mandatory salt iodization, 3.9% were aware of guidelines on salt marketing and only 18.2% handled salt safely. Safe handling practices were found among all wholesalers and 44.7% of the retailers. Qualitative findings revealed the existence of regulation on the production, packing and marketing of salts in Nigeria, however, enforcement and monitoring at the market level is weak. The demand and use of industrial salt in food preparation remain widespread among consumers in Ibadan, Nigeria following limited awareness of salt iodization programme and its benefits. Regulations on salt marketing should be enforced at all levels and nutrition education on salt iodization should be intensified.

Adjusting the Iodine Content of Iodized Salt to Meet the Recommended Intake for Females of Reproductive Age: A Simulation Study with a Reduced Sodium Scenario

BACKGROUND

The use of iodized salt is a key strategy to increase iodine intake worldwide. In many countries, including New Zealand, females of reproductive age are still at risk of being mildly iodine deficient.

OBJECTIVE

This study aimed to determine the level of iodization of salt needed to ensure that females aged 18 to 40 y have an adequate intake of iodine in 2 scenarios: current discretionary salt intake and reduced discretionary salt intake.

METHOD

Data from nonpregnant, nonlactating females aged 18 to 40 y (n = 795) who took part in the 2008/09 New Zealand Adult Nutrition Survey and completed a 24-h dietary recall were used. Iodine intake was determined from all foods except bread and discretionary salt, which are fortified with iodine. Iodine from bread and salt was estimated at different levels of salt iodization, starting at 25 mg iodine/kg salt and increasing incrementally by 5 mg/kg, and added to calculate total iodine intake. The simulation concluded when the appropriate iodine content in salt was found using the estimated average requirement (EAR) cut-point method.

RESULTS

In the 2 scenarios, current discretionary salt intake (i.e., 400 mg/d) and reduced discretionary salt intake (i.e., 304 mg/d), the iodine concentration of salt is required to be 55 mg/kg and 70 mg/kg for no more than 2% of females to have an iodine intake below the EAR of 100 μg of iodine/d, respectively. In both scenarios and at all levels of iodine concentration, no one was above the upper level of intake of iodine of 1100 μg/d.

CONCLUSIONS

This study found that females of reproductive age need to consume iodized salt at the higher end of the legislated range of 25 to 65 mg/kg. If strategies to reduce sodium intake were adopted, the range would need to increase, or iodized salt would need to be included in a wider range of staple foods.

Survey of iodized salt coverage in areas with different water iodine concentrations and the iodine status of local women

PURPOSE

There were only two definitions of iodine-deficient (water iodine concentration < 10 μg/L) and iodine-excess areas (water iodine concentration > 100 μg/L) in China before 2020. Areas with water iodine concentration between 10 and 100 μg/L implement the same policy as iodine-deficient areas to provide iodized salt. The definition of iodine-adequate areas was formulated in 2020 for the first time. The paper aims to investigate the coverage rate of iodized salt (CR) in different areas defined according to the latest national standards, evaluate the iodine status of local women, and provide a basis for the revision and improvement of relevant policies.

METHODS

A total of 1948 women aged 18-60 were recruited from the iodine extra-high areas (IEHA), iodine-excess areas (IEA), iodine-adequate areas (IAA), inland iodine-deficient areas (IIDA), and coastal iodine-deficient areas (CIDA). Information on daily diet was collected with the Food Frequency Questionnaire. Drinking water, salt, food, and urine samples were collected and tested in our laboratory. Based on the recommended daily iodine intake, we assessed whether the subjects' daily iodine intake levels were adequate.

RESULTS

The CR and the median urinary iodine concentrations (UICs) were 4.02% and 98.03 μg/L in CIDA, 89.74% and 144.93 μg/L in IIDA, 26.55% and 178.60 μg/L in IAA, 8.78% and 446.5 μg/L in IEA, 3.95% and 605.4 μg/L in IEHA, respectively. The differences among these five areas were statistically significant (P < 0.0001). The daily dietary iodine intakes were mainly from drinking water in IAA (63.92%), IEA (92.29%), and IEHA (92.93%), and were mainly from iodized salt in IIDA (59.22%) and food in CIDA (86.6%).

CONCLUSION

Women in IAA and IIDA were in an adequate iodine state. Women in IEA and IEHA were in an iodine-excess state, and it is necessary to carry out water improvements projects. Women in CIDA were in a slight iodine-deficient state, and health education on scientific iodine fortification should be strengthened to increase iodine intake.

Investigation of the effects of heat and light on iodine content of packaged and open salt brands collected from Jimma town

Iodine deficiency is one of the most common micronutrient deficiencies in developing countries, which leads to iodine deficiency disorders (IDD). To combat iodine deficiency disorders, universal salt iodization is mandatory. However, iodized salt can lose its iodine due to environmental factors such as heat, light, moisture, and so on. Therefore, the aim of this study is to investigate the effects of heat and light on the iodine content of packaged and open salt brands available in Jimma town, Oromia, Ethiopia. An experimental study design was employed to determine the effects of heat and light on the iodine content of salts. A total of six salt samples were collected from retailers selected based on convenience sampling technique. Among six different salt brands, three were packaged salts, and the rest were non-packaged (open) salts. The iodine content of the salt samples was determined by the iodometric titration method, and the effects of heat and light on the concentration of iodine were also investigated. It has been revealed that heat and light decrease the iodine content of salt samples. The findings of this study provide valuable insights into the stability of iodized salt against heat and light. It is also helpful in identifying the right time at which salt should be added while cooking and the appropriate storage conditions for salt in households.

Factors associated with recent iodine intake level among household food handlers in Southwest Ethiopia: a cross-sectional study

BACKGROUND

Iodine deficiency is a global public health threat, affecting an estimated two billion people. The median urinary iodine concentration is more reliable in determining recent iodine intakes and the risks of iodine deficiency. Therefore, this study was aimed to identify the factors associated with recent iodine intake level using median urinary iodine concentration as an indicator among household food handlers in southwest Ethiopia.

METHODS

A community-based survey was conducted with selected households using a pretested interviewer-administered questionnaire in southwest Ethiopia. A 20-gram sample of table salt and a 5 ml causal urine samples were also collected and analyzed using rapid test kit and a Sandell-Kolthoff reaction, respectively. A salt iodine concentration above 15 ppm was classified as adequately iodized and a median urinary iodine concentration between 100 and 200µgl^- 1 was considered as adequate iodine intake. A bivariable and multivariable logistic regression model was fitted. Crude and adjusted odds ratios with their 95% confidence levels were reported. Associations with a p-value ≤ 0.05 were used to declare statistical significance.

RESULTS

A total of 478 women were included, with a mean age of 33.2 (± 8.4 years). Only 268 (56.1%) of the households had adequately iodized salt (> 15 ppm). The median urinary iodine concentration (interquartile range) was 87.5 µg l^- 1 (45.6-107.6). In a fitted multivariable logistic regression model (p-value = 0.911), illiterate women (AOR = 4.61; 95% CI: 2.17, 9.81), poorly iodized salt in the household (AOR = 25.0; 95% CI: 13-48), salt purchased from open market (AOR = 1.93; 95% CI: 1.0, 3.73) and women who do not read the label during purchasing the salt (AOR = 3.07; 95% CI: 1.31, 7.17) were important predictors of the risk of Iodine deficiency.

CONCLUSION

Despite public health efforts to improve iodine intake, its deficiency is still a major public health problem among southwest Ethiopian women.

Availability of adequate iodized salt at household level in rural communities in Farta district, Northwest, Ethiopia: a cross-sectional study

INTRODUCTION

Iodine is a crucial trace element for thyroid hormone synthesis. All age groups are affected by iodine deficiency disorders (IDD), especially pregnant women, young women, and children. Iodine deficiency disorder has been recognized as a serious public health issue in Ethiopia. Therefore, the aim of the current study was to assess the availability of iodized salt and associated factors at the household (HH) level in the Farta district, northwest, Ethiopia.

METHODS

A community-based cross-sectional study was conducted involving 704 participants in Farta District, Northwest Ethiopia, between February and March 2021. A multi-stage sampling technique was employed to recruit participants. Data were collected using pretested and structured questionnaires administered by face-to-face interviewers. The data were entered into Epi-data version 4.6 software and exported into Stata version 14 for the purpose of analysis. Both bivariable and multivariable logistic regression analyses were used to identify factors associated with the availability of iodized salt. Statistical significance was declared at a p-value ≤ 0.05 with a corresponding 95% confidence interval.

RESULTS

The availability of adequately iodized salt in the study area was 26.6% (CI = 23.8%, 29.4%) of households. Good knowledge about iodine deficiency disorder (IDD) and iodized salt (AOR = 3.85, 95% CI: 3.65, 6.11); short-term storage of salt at the HH [AOR = 2.76, 95% CI: 1.98, 3.23); and stored in covered containers (AOR = 1.57, 95% CI: 1.11, 1.78) were significantly associated with the outcome variable.

CONCLUSION

The availability of adequate iodized salt at the HH level was far below the WHO target (more than 90%) in the study area. Knowledge about IDD and iodized salt, stored in covered containers, and short-term storage of salt at the HH were significantly associated with the availability of iodized salt. Hence, at the household level, increasing awareness and disseminating information about the benefits of using iodized salt could be effective. Moreover, education about the proper storage and handling of iodized salt, as well as the recommended storage duration of salt in the home, should be provided as part of our community outreach programs.

Changes of Iodine Nutritional Status in the Elderly after Replacing Iodized Salt with Non-Iodized Salt for Half a Year

China has issued the "Reform Plan of the Salt Industry System" in 2016 and it is necessary to attach the importance to the changes of iodine nutritional status of those people who might consume non-iodized salt for a long time. Forty-six elderly subjects were recruited and replaced iodized salt with non-iodized salt for 6 months. Urine iodine concentration (UIC), dietary iodine intake, thyroid function, thyroid B-ultrasound, and plasma iodine were monitored during the follow-up period. The median dietary iodine intakes of the baseline, the 1st, 2nd,3rd, 4th, and 6th month were 255.3 µg/d, 183.6 µg/d, 164.6 µg/d, 179.2 µg/d, 139.4 µg/d, and 146.9 µg/d, respectively. The median UIC of baseline and follow-up was 155.7 (111.0-263.1) µg/L and 69.7(36.7-119.8) µg/L, respectively. The proportion of urinary iodine less than 50 g/L at the baseline and follow-up was 3.0 (0 ~ 8.9)% and 36.0 (33.1 ~ 38.9)%, respectively. Dietary iodine intake had a significant correlation with urine iodine. Six subjects (15.4%) had abnormal thyroid function. Three subjects (7.7%) had first-onset new nodules or enlarged solid nodules and the median UIC of these three subjects during the follow-up period was 39.8 µg/L, which was significantly lower than that of other subject (74.0 µg/L). T4 and T3 had a significant correlation with plasma iodine. The importance of monitoring and evaluating iodine nutrition of people consuming non-iodized salt should be stressed to prevent the potential poor iodine nutrition and iodine deficiency diseases.

Multiple micronutrients fortified salt: consumers' acceptability survey, Tanzania

BACKGROUND

Food fortification with micronutrients is an insufficiently used technology in developing countries. Salt is consumed in small, constant daily amounts by most people globally. Salt has been instrumental in delivering iodine to a wide population globally through fortification. There is a proven effective technology for fortifying iodinated salt with iron, folate, and Vitamin B12. Findings have shown that both Double (Iodine and iron) fortified salt (DFS) and quadruple (iron, iodine, folate, and vitamin B12) fortified salt (QFS) are effective in raising hemoglobin levels.

AIM

To assess the acceptability and gauge consumers' willingness to use double-fortified and quadruple-fortified salt formulations.

METHODS

We conducted an observational study involving 300 households at Haydom Lutheran Hospital catchment area in Northern rural Tanzania between October 2021 and April 2022. Each household was supplied with one type of salt (iodized salt (IS), DFS or QFS) for cooking common family dishes for one week. Thereafter, at least two adult members of the family who used the dishes cooked with study salt were interviewed using the adopted 5-point Hedonic scale.

RESULTS

A total of 899 individuals were interviewed after using study salt for one week: 286 IS, 305 DFS, and 308 QFS. The overall acceptability for the salts was QFS (82%), DFS (78%), and IS (79%). The mean sensory (taste, color and appearance) scores of the QFS (1.7) and DFS (1.7) were comparable to standard iodized salt (1.6).

CONCLUSION

Quadruple-fortified salt and double-fortified salt are equally acceptable and have similar sensory scores as standard iodized salt when used to cook commonly eaten dishes in the study population.

Analysis of the correlation between high iodized salt intake and the risk of thyroid nodules: a large retrospective study

BACKGROUND

Currently, whether daily excess iodized salt intake increases the risk of thyroid nodules and even thyroid cancer remains controversial. Our research group aimed to provide a theoretical basis for the clinical guidance of daily iodized salt intake and the prevention of thyroid nodules through a retrospective analysis of the correlation between daily iodized salt intake and the risk of thyroid nodules and thyroid cancer in Hunan, China.

METHODS

This study retrospectively analyzed the data of subjects who underwent a physical examination at the Health Management Center, Third Xiangya Hospital of Central South University, between January 1, 2017, and December 31, 2019. Subjects enrolled in this study underwent thyroid ultrasonography and tests to urine routines and liver and kidney function, and all subjects completed a questionnaire survey. The daily iodized salt intake of the study subjects was estimated based on spot urine methods (Tanaka). A multivariate logistic regression model was used to analyze the relationship between daily iodized salt intake and thyroid nodules and thyroid cancer.

RESULTS

Among the 51,637 subjects included in this study, the prevalence of thyroid nodules was 40.25%, and the prevalence of thyroid cancer was 0.76%; among all enrolled subjects, only 3.59% had a daily iodized salt intake less than 5 g. In addition, we found that a daily intake of more than 5 g of iodized salt was not only an independent risk factor for the occurrence of thyroid nodules (odds ratio (OR): 2.08, 95% confidence interval (CI): 1.86-2.31, p < 0.001) but also an independent risk factor for the occurrence of thyroid cancer (OR: 5.81, 95% CI: 1.44-23.42, p = 0.012). A pooled analysis showed a significantly higher risk of thyroid nodules in subjects aged > 60 years with a daily iodized salt intake of more than 5 g compared to subjects aged < 60 years with a daily iodized salt intake of no more than 5 g (OR: 4.88, 95% CI: 4.29-5.54, p < 0.001); the risk of thyroid cancer was not significantly different between subjects aged > 60 years with a daily iodized salt intake of more than 5 g and those aged < 60 years with a daily iodized salt intake of no more than 5 g (OR: 2.15, 95% CI: 0.52-8.95, p = 0.281). The risk of thyroid nodules was not increased in physically active subjects with a daily iodized salt intake of more than 5 g compared to physically inactive subjects with a daily iodized salt intake of no more than 5 g (OR: 1.12, 95% CI: 0.97-1.28, p = 0.111). The same protective effect of physical activity was observed for thyroid cancer in subjects whose daily iodized salt intake exceeded 5 g. The risk of thyroid nodules was reduced for subjects with an education level of postgraduate and above, even when the daily iodized salt intake exceeded 5 g, compared to those with high school education and below and a daily iodized salt intake of no more than 5 g (OR: 0.79, 95% CI: 0.66-0.93, p = 0.005); however, a protective effect of education level on the occurrence of thyroid cancer was not observed. Independent risk factors affecting daily iodized salt intake greater than 5 g included age, triglycerides, family history of tumors, physical activity, and marital status.

CONCLUSIONS

Daily intake of more than 5 g of iodized salt increased the risk of thyroid nodules and thyroid cancer, while increased physical activity and education level reduced the risk of thyroid nodules and thyroid cancer caused by iodized salt intake.

Iodoprophylaxis and thyroid autoimmunity: an update

Adequate iodine intake is necessary for normal thyroid function. Iodine deficiency is associated with serious complications, but also iodine excess can lead to thyroid dysfunction, and iodine supplementation aimed to prevent iodine deficiency disorders has been associated with development of thyroid autoimmunity. The epidemiology of thyroid diseases has undergone profound changes since the implementation of iodoprophylaxis, notably by means of iodine-enriched salt, specifically resulting in decreased prevalence of goiter and neonatal hypothyroidism, improved cognitive function development in infancy, and reduced incidence of more aggressive forms of thyroid cancer. The main question we address with this review is the clinical relevance of the possible effect on autoimmunity exerted by the use of iodine-enriched salt to correct iodine deficiency. In animal models, exogenous iodine is able to trigger or exacerbate thyroid autoimmunity, but it is still not clear whether the observed immunological changes are due to a direct effect of iodine on immune response, or whether they represent a secondary response to a toxic effect of iodine on thyroid tissue. Previous iodine status of a population seems to influence the functional thyroid response to increased iodine intake and possibly the development of thyroid autoimmunity. Moreover, the prevalence of thyroid antibodies, regarded as hallmark of autoimmune thyroid disease, varies between populations under the influence of genetic and environmental factors, and the presence of thyroid antibodies does not always coincide with the presence of thyroid disease or its future development. In addition, the incidence of autoimmune diseases shows a general increasing trend in the last decades. For all these reasons, available data are quite heterogeneous and difficult to analyze and compare. In conclusion, available data from long-term population surveys show that a higher than adequate population iodine intake due to a poorly controlled program of iodine prophylaxis could induce thyroid dysfunction, including thyroid autoimmunity mostly represented by euthyroid or subclinical hypothyroid autoimmune thyroiditis. Close monitoring iodine prophylaxis is therefore advised to ensure that effects of both iodine deficiency and iodine excess are avoided.

Iodine status five years after the adjustment of universal salt iodization: a cross-sectional study in Fujian Province, China

Background

Universal salt iodization program was introduced to China to eliminate iodine deficiency disorders in 1995. In 2012, Fujian Province decreased the concentration of iodized table salt according to the national unified requirement. This study aimed to assess the effect on iodine status after the adjustment, providing evidence for further adjustment in Fujian Province.

Methods

Sampling units were selected by multistage cluster sampling method. In each sampling unit, table salt was collected from 30 households. A total of 2,471 people in 2009 and 4,806 people in 2017 provided urine samples and were included in this cross-sectional analysis. Median iodized salt concentration and median urine iodine concentration were present by median and interquartile range.

Results

Median iodized salt decreased from 29.8 mg/kg in 2009 to 23.9 mg/kg in 2017. The median urinary iodine concentrations for school-age children in 2017 in coastal urban area, non-coastal urban area, coastal rural area and non-coastal rural area were 163.6µg/L (interquartile range = 100.1–252.0µg/L), 198.9µg/L (interquartile range = 128.0-294.0µg/L), 181.8µg/L (interquartile range = 114.1–257.0µg/L) and 218.2µg/L (interquartile range = 148.1-306.5µg/L), respectively. The median urinary iodine concentrations for adults in 2017 in these areas were 151.1µg/L (interquartile range = 98.3-231.7µg/L), 168.7µg/L (interquartile range = 109.6–242.0µg/L), 167.7µg/L (interquartile range = 105.7-245.7µg/L) and 182.7µg/L (interquartile range = 117.1-258.9µg/L). The median urinary iodine concentrations for pregnant women in 2017 in these areas were 157.7µg/L (interquartile range = 106.9-223.8µg/L), 141.5µg/L (interquartile range = 97.7-207.6µg/L), 127.3µg/L (interquartile range = 90.0-184.5µg/L) and 144.8µg/L (interquartile range = 99.9-184.5µg/L). The median urinary iodine concentrations for lactating women in 2017 in these areas were 122.7µg/L (interquartile range = 84.1–172.0µg/L), 123.7µg/L (interquartile range = 70.7-184.7µg/L), 105.8µg/L (interquartile range = 67.1-152.3µg/L) and 110.2µg/L (interquartile range = 74.1-170.3µg/L).

Conclusions

The overall urinary iodine concentrations among school-age children, adults and lactating women dramatically decreased after implementing the new standard. Almost all of them were iodine adequate, suggesting we reached the expected aim of iodized salt adjustment. However, pregnant women were iodine insufficient after adjustment. Therefore, we should continue the surveillance of iodine status of populations and focus on the additional iodine supplement strategies for pregnant women.

Iodine intake among pregnant mothers residing in hilly terrains of two districts of Himachal Pradesh, India

Background

Under programmatic settings, routine monitoring and evaluation of household consumption of iodized salt are recommended to track the reach of universal salt iodization strategy. The program needs evaluation in different settings and locations.

Objective

The objective of this study was to assess urine-based estimation for recent iodine intake among pregnant women living in hilly terrains of two districts of northern state of India.

Methods

A community-based cross-sectional observational study was conducted during September- December 2019 among 202 randomly selected pregnant women in two districts of Himachal Pradesh. With a predesigned schedule, data regarding sociodemographic and behavioral factors and salt consumption were collected by interview. Iodine level of salt was assessed by spot iodine testing kit and urinary iodine concentration (UIC) was measured using ammonium persulfate digestion using spectrophotometer.

Results

Women had a mean age of about 26 years, and the period of gestation was of mean 163.7 days. The consumption of iodized salt (>15 ppm) at family level was found to be 83.7%, and the median UIC was 169.0 μg/L. Among assessed, 26.7% had an acceptable level of UIC, whereas 41.1% and 32.2% of women had less (<150 μg/L) and excessive (>250 μg/L) level of UIC, respectively.

Conclusion

Recent iodine intake among pregnant women was observed to be adequate, but efforts are to be done to assess the reasons for less and excessive UIC among women.

Trend of Iodine Status in the Eastern Mediterranean Region and Impact of the Universal Salt Iodization Programs: a Narrative Review

Recognizing the importance of iodine deficiency as a single most important preventable cause of brain damage, World Health Organization (WHO) urged all countries to scale up salt iodization since 1991 where iodine deficiency was declared as a global public health problem. All countries committed to report on the national iodine status of school-aged children (6-12 years), every 3 years. This paper aims to evaluate the progress of countries in Eastern Mediterranean Region (EMR) toward the eradication of iodine deficiency disorders (IDD) and recommend operational action to support implementation of the WHO Regional Nutrition Strategy (2020-2030). Salt iodization in EMR has been scaled up with significant progress in increasing the proportion of dietary salt which is adequately iodized. As a result, many countries such as Qatar, Kuwait, Bahrain, Jordan, Oman, and Iran have achieved, or are now on the threshold of achieving IDD elimination. The WHO in coordination with United Nations Children's Fund is working with member states to ensure suitability of these achievements. Hence, efficient monitoring will help member states to measure the magnitude of IDD as a public health problem and to monitor the effects of the intervention on the iodine status of a population. Policy makers should take proactive steps to enforce mandatory regulatory measures for USI, through a multi-sectoral coordination, and careful assessments and estimates of iodine nutritional status. Coordination between the two national programs of USI and salt reduction intake is necessary.

Salt-reduction strategies may compromise salt iodization programs: Learnings from South Africa and Ghana

OBJECTIVES

Universal salt iodization has been adopted by many countries to address iodine deficiency. More recently, salt-reduction strategies have been widely implemented to meet global salt intake targets of <5 g/d. Compatibility of the two policies has yet to be demonstrated. This study compares urinary iodine excretion (UIE) according to 24-h urinary sodium excretion, between South Africa (SA) and Ghana; both countries have implemented universal salt iodization, but in Ghana no salt-reduction legislation has been implemented.

METHODS

Participants from the World Health Organization's Study on Global Ageing and Adult Health Wave 3, with survey and valid 24-h urinary data (Ghana, n = 495; SA, n = 707), comprised the sample. Median 24-h UIE was compared across salt intake categories of <5, 5-9 and >9 g/d.

RESULTS

In Ghana, median sodium excretion indicated a salt intake of 10.7 g/d (interquartile range [IQR] = 7.6), and median UIE was 182.4 µg/L (IQR = 162.5). In SA, both values were lower: median salt = 5.6 g/d (IQR = 5.0), median UIE = 100.2 µg/L (IQR = 129.6). UIE differed significantly across salt intake categories (P < 0.001) in both countries, with positive correlations observed in both-Ghana: r = 0.1501, P < 0.0011; South Africa: r = 0.4050, P < 0.0001. Participants with salt intakes <9 g/d in SA did not meet the World Health Organization's recommended iodine intake of 150 µg/d, but this was not the case in Ghana.

CONCLUSIONS

Monitoring and surveillance of iodine status is recommended in countries that have introduced salt-reduction strategies, in order to prevent reemergence of iodine deficiency.

Effect of nutrition education on iodine deficiency disorders and iodized salt intake in south west Ethiopian women: a cluster randomized controlled trial

BACKGROUND

Although iodine nutrition status is improving globally, the progress is not uniform throughout the world due to several factors. Among these, poor knowledge, negative attitude and improper practice of iodized salt are the main risk factors for poor iodine nutrition in Ethiopia. This study was aimed to assess the effect of nutrition education intervention on knowledge, attitude and practice (KAP) of iodine deficiency and iodized salt utilization.

METHODS

A cluster randomized controlled trial was carried out among 652 women of reproductive age group in southwest Ethiopia. A total of 24 clusters were selected and randomized in to an intervention and control villages. Women in the intervention village received iodine nutrition related education for 6 months; while those in the control village did not receive any education. Baseline and endline data were collected from both groups. Generalized Estimating Equations (GEE) was used to determine the effect of intervention.

RESULTS

A total of 647 (99.2%) participants were successfully involved in the study. In the intervention group the median attendance was 10 out of 12 sessions. Women in the intervention group had shown statistically significant change in knowledge, attitude and practice scores as compared to control one. In multivariable GEE linear model, after adjusting for other background characteristics, the mean difference (95% CI) scores were 8.81 (8.46, 9.16) for knowledge, 3.35 (3.17, 3.54) for attitude and 2.90 (2.74, 3.05) for practice in the intervention arm.

CONCLUSIONS

Well designed and community-based iodine nutrition education is an effective strategy to improve the KAP of iodine deficiency disorders and iodized salt utilization. Trial registration PACTR201809544276357 (Retrospectively registered on 14, Sept. 2018). https://www.pactr.org .

Iodine nutrition status and its association with microvascular complications in urban dwellers with type 2 diabetes

Background

The principal function of iodine acts on thyroid function, but in recent years, the role of iodine deficiency in metabolism has also been gradually revealed. We aimed to investigate the current status of iodized salt consumption and urinary iodine concentration (UIC) in an urban Chinese population with type 2 diabetes, and to further explore whether UIC was associated with diabetic microvascular complications.

Methods

Four thousand five hundred fifty-nine subjects with diabetes from 7 communities in downtown Shanghai were enrolled in the cross-sectional Metal Study in 2018. UIC was detected using an inductively coupled plasma-mass spectrometer. Diabetic kidney disease (DKD) was defined as urinary albumin-to-creatinine ratio (UACR) > 30 mg/g or estimated glomerular filtration rate < 60 mL/min/1.73 m². Diabetic retinopathy (DR) was evaluated by high-quality fundus photographs and was remotely read by ophthalmologist.

Results

The median UIC of subjects with diabetes was 115.4 μg/L (78.9–170.8) in downtown Shanghai. Among all the subjects, 52.7% consumed non-iodized salt and 40.4% were iodine deficient. Iodine deficiency (UIC < 100 μg/L) was associated with an increased odds of DKD (OR 1.17; 95%CI 1.01–1.37) after adjustment for age, sex, education, current smokers, BMI, HbA1c, duration of diabetes, dyslipidemia, thyroid-stimulating hormone and free thyroxine. No association was observed between UIC and DR after multivariable adjustment.

Conclusions

A concerning number of subjects with diabetes consumed non-iodized salt and suffered from iodine deficiency in coastal regions of China. Low UIC might be a risk factor for DKD, which should be further confirmed by longitudinal prospective studies.

Knowledge, attitude, and practice of iodized salt use in Al-Riyadh and Al-Ozozab areas, Khartoum, Sudan

Iodine deficiency and subsequent iodine deficiency disorders have been a longstanding problem in many areas of the world, including Sudan, and still remains as the leading cause of preventable brain damage. According to the Sudan Household Health Survey, in 2006, the consumption of iodized salt in Sudan was 11%, only to deteriorate later on in 2011 to 9.5%. This is a descriptive cross sectional study which assesses the knowledge, attitude, and practice regarding the use of iodized salt in two socioeconomically different residential areas, Al-Riyadh and Al-Ozozab, Khartoum city, Sudan. From total of 152 participants selected from Al-Riyadh and Al-Ozozab areas (50% from each), there were 87 (57 %) females. Participants from Al-Riyadh had a higher educational and income level than those from Al-Ozozab, and better knowledge regarding the importance of regular iodized salt consumption to treat iodine deficiency (61% and 54%, respectively). However, only 39% of the participants were actually buying iodized salt. There was a significant relationship between residency and buying of iodized salt among the participants from Al-Riyadh (49%) and Al-Ozozab (30%) areas (p-value = 0.02). There was also significant association between the educational level and buying iodized salt (p-value = 0.014), but not with the income (p-value = 0.23). The consumption of potential goitrogenic foods (pearl millet or peanut butter) was high among the participants (n = 142) from Al-Riyadh and Al-Ozozab, and constituted 76% and 83%, respectively. Compulsory national salt specification needs to be established in Sudan, together with monitoring the market availability of iodized salt.

High prevalence of TPO-Abs and subclinical hypothyroidism in iodine-sufficient pregnant women in Northern Algeria

BACKGROUND

Iodine is a trace element whose adequate intakes are essential during gestation to promote the correct growth and development of the fetus. Historically, endemic goiter and cretinism affected northern regions of Algeria, and iodized salt was introduced in 1990. However, there has been no national study of iodine nutrition in Algeria since 1994. The aim of this study was to assess the iodine status and thyroid function of women of reproductive age (WRA) and pregnant women (PW) in northern Algeria.

METHODS

Healthy WRA and PW were recruited from an urban area (Algiers) and healthy WRA from a rural area (Tizi-Ouzou). Spot urine and venous blood samples were collected to assess iodine status (urinary iodine concentration, UIC) and serum thyroid hormones (TSH, FT4), thyroglobulin (Tg), and anti-thyroid peroxidase antibodies (TPO-Ab) concentrations.

RESULTS

The median UIC in WRA was 256 μg/L (IQR: 166-354 μg/L; n = 151) in Algiers and 253 μg/L (167-341 μg/L; n = 150) in Tizi-Ouzou. The median UIC for the PW in Algiers was 233 μg/L (IQR: 157-326 μg/L; n = 173).Thirty-five percent of WRA and 30% of PW had an UIC > 300 μg/L. Median TSH, FT4 and Tg concentrations were within reference ranges in all groups of women. Among PW, 72.7%, 75.4% and 75.5% in the first, second and third trimester were TPO-Ab+. Among TPO-Ab + PW in the first, second and third trimesters, 18.7%, 13% and 10.3% had subclinical hypothyroidism.

CONCLUSION

In northern Algeria, median UICs in PW indicate iodine sufficiency, and in WRA indicate more than adequate intakes. About 75% of PW are TPO-Ab + and the prevalence of subclinical hypothyroidism is high. Monitoring and surveillance of iodine fortification programs is vital to avoid both iodine deficiency and excess. There is an urgent need for a comprehensive national iodine status survey including school-age children and other vulnerable population groups in Algeria.

Change over time in the iodine nutritional status of pregnant women from the Pamplona healthcare region

INTRODUCTION

Adequate iodine intake is essential during pregnancy. A previous study of pregnant women from the Pamplona healthcare region showed mild iodine deficiency (mean urinary iodine level, 125 mcg/L). This study was intended to ascertain the iodine intake of pregnant women in our region and to analyze the change over time in their iodine nutritional status.

METHODS

An observational study of 400 women in their first trimester of pregnancy. An iodine intake questionnaire was administered. To assess iodine status, urinary iodine concentration (UIC) was measured in a simple urine sample, and serum thyroglobulin levels were determined. In addition, thyroid volume was measured by cervical ultrasound examination.

RESULTS

Iodized salt was used by 70.5% of all participants (55.3% since the pre-gestational period) and 98.5% of them received iodine-containing supplements (mean dose, 202.6±30.1 mcg/day). Mean urinary iodine concentration was 242 mcg/L (138.5-415.5 mcg/L) and the mean serum thyroglobulin level was 12.3 mcg/L (8.3-9 mcg/L). Iodized salt intake was associated with higher UICs and lower thyroid volume. No differences were found in any of the tested parameters regarding the intake of dairy products, fish, or eggs.

CONCLUSIONS

Iodine intake by pregnant women in Pamplona has increased due to a greater use of iodized salt and to higher doses of iodine supplements. As a result of this, an adequate iodine status has been achieved in the last decade.

Assessment of Iodine Status in Iranian Students Aged 8-10 Years: Monitoring the National Program for the Prevention and Control of Iodine Deficiency Disorders in 2016

BACKGROUND

Iodine is a key element in the synthesis of thyroid hormones. The deficiency of the secretion of them will Reduce IQ, disturbance in the psychomotor growth and shortened height. Urinary iodine is a good indicator of iodine intake status. Urinary iodine status in at-risk groups is one of the most important indicators of community status.

METHODS

All 56 universities/medical faculties in Iran should determine and report median urinary iodine and its relative distribution in school children aged 8 to 10 yr, to determine the status of urine output. The sample size in each university/college is 240 students and the cluster sampling method (48 clusters in each area in 2016) and based on probability Measurement. The amount of urinary iodine was measured quantitatively by acid digestion.

RESULTS

The mean urinary iodine excretion was estimated at 18.61 μg/dl. The median urinary iodine concentration in 52 universities was sufficient, and the national mean of urinary iodine excretion rate was 19.3 μg/dl. The iodine status was estimated in the optimal range in 65.6% of the students and in only 4.7% in the range of moderate and severe deficits, based on the urinary iodine index.

CONCLUSION

Iodine is sufficient in most parts of the country. The implementation of the country's national program for the prevention and control of iodine deficiency disorders has made more important the quality control of the collaborative laboratories of this program than before. Moreover, it is absolutely essential to avoid excessive iodine in order to prevent possible side effects.

Stopping the supply of iodized salt alone is not enough to make iodine nutrition suitable for children in higher water iodine areas: A cross-sectional study in northern China

BACKGROUND

For the sake of children's health, iodized salt supply has been stopped in many areas with excessive iodine in the drinking water, but children's iodine nutrition status and thyroid function after terminating the iodized salt supply is unknown. Objective We assessed the iodine nutrition, thyroid function and influencing factors for thyroid abnormalities in children from areas with different concentrations of water iodine; the supply of iodized salt has been stopped in high water iodine areas. This study aimed to evaluate whether the strategy of stopping the supplies of iodized salt alone is enough to avoid thyroid dysfunction in all areas with excess water iodine while still meeting the iodine nutrition needs of children.

METHODS

A cross-sectional study was conducted in children from four areas with different drinking water iodine concentrations in Tianjin, China. The drinking water samplings and spot urine samples were collected to estimate the external and internal iodine exposure levels. The thyroid volume was measured, and blood samples were collected to assess thyroid function. Logistic regression analysis was used to analyze risk factors for thyroid abnormalities. A dietary survey was conducted to determine the sources of iodine nutrition among the areas with different iodine concentrations in the drinking water.

RESULTS

In the area with a drinking water iodine concentration ≥300 μg/L, the median urinary iodine concentration (UIC) in children was 476.30 (332.20-639.30) μg/L, which was higher than that in other groups (all P < 0.05), and the prevalence of thyroid nodules and the thyroid goiter rate were higher than those in the <100 μg/L, 100-150 μg/L and 150-300 μg/L areas (all P < 0.01). Binary logistic regression analysis indicated that the risk of thyroid abnormalities was significantly increased in the UIC 200-299 μg/L group (OR: 4.534; 95% CI: 1.565, 13.135; bootstrapped 95% CI: 1.689, 21.206, P = 0.004) and in the UIC ≥ 300 μg/L group (OR: 6.962; 95% CI: 2.490, 19.460; bootstrapped 95% CI: 2.838, 32.570, P = 0.001) compared to the 100-199 μg/L group. The iodine contribution rates from water in areas with water iodine concentrations ≥300 μg/L are up to 63.04%.

CONCLUSIONS

After termination of the iodized salt supply, the level of iodine nutrition of children in the area with drinking water iodine concentrations ≥300 μg/L is still excessive. The water source needs to be replaced in this area. In the area with a water iodine concentration of 150-300 μg/L, it is proposed that stopping the supply of iodized salt is sufficient to achieve the proper iodine nutrition status in children.

Contribution of iodized salt to total iodine and total salt intake in Germany

BACKGROUND

Salt reduction campaigns without a parallel increase of iodine fortification will lead to a worsened iodine status in countries with a relevant salt iodization. A decline in iodine supply bears the risk of higher prevalences of goiter, thyroid nodules, and cognitive delay in children. Against this background, we analyzed the contribution of iodized salt to total iodine and salt intake in Germany and compared the results with data from Switzerland.

METHODS

Analyses were performed with data of the representative German Health-Interview and Examination-Survey for Adults (DEGS1, 2008-2011) using spot urine measurements of creatinine, iodine, and sodium (n = 6738). Median daily iodine and salt intakes were calculated by estimating 24-h iodine and sodium excretions from urinary analyte/creatinine ratios. Linear regressions were used to deduce iodine intake that originates from iodine containing foods (i.e., salt-independent iodine). From this, ingested iodine originating from salt and the proportion of iodized salt to total salt intake were calculated. Data from Switzerland were obtained from the literature.

RESULTS

In Germany, only 42% (52.2 µg/d) of the predicted median total iodine intake (126.2 µg/d), i.e., 12% less than in Switzerland, were found to originate from salt, whereas 73.7 µg/d came from iodine containing foods. 28% (2.6 g/d) of the median salt intake (9.3 g/d) of the German population was calculated to represent iodized salt against 43% in Switzerland.

CONCLUSIONS

Along with an almost identical inherent iodine intake in Germany and Switzerland, the average total iodine intake, the contribution of iodized salt to total iodine intake, and the proportion of iodized salt to total salt are higher in Switzerland than in Germany. Despite this, iodine fortification of table salt has recently been increased in Switzerland from 20 to 25 mg/kg to ensure iodine sufficiency in the population, whereas in Germany fortification still remains at a mean level of 20 mg/kg implying a growing risk of increasing iodine deficiency rates if general salt intake drops.

Influence of cooking on the iodine content in potatoes, pasta and rice using iodized salt

To counteract iodine deficiency in the population in areas of environmental iodine deficiency table salt is often fortified with potassium iodide or iodate. However, most estimations of iodine contribution from the diet rely on calculations based on the added iodized salt and very limited experimental data about the stability of potassium iodate (KIO₃) or iodine uptake during food processing is available. Therefore, the influence of cooking on the iodine content of potatoes, pasta, and rice having different size, varieties or composition was investigated. Commonly used cooking procedures were applied, using KIO₃-enriched table salt in the cooking water. After iodine extraction with 0.5% NH₃ iodine content was measured by ICP-MS. All products showed an increase in iodine content. Waxy potatoes, especially cut in small pieces, and egg pasta showed the highest iodine uptake. Based on the results, the use of KIO₃-enriched salt for cooking is recommended to enhance iodine supply.

Iodine level concentration, coverage of adequately iodized salt consumption and factors affecting proper iodized salt utilization among households in North Ethiopia: a community based cross sectional study

Introduction

Adequate iodine fortified salt is the most common and effective method of preventing iodine deficiency. Studies showed households using iodized salt (15 Parts Per Million (PPM) to 80 PPM) of iodine at household level were low in Tigray region and other regions of Ethiopia. Limited studies have conducted on utilization of iodized salt at the household level and none of them did not addressed on factors affecting to proper iodized salt utilization. The aim of this study was to determine the iodine concentration in the collected salt samples, adequately iodized salt consumption coverage and identify factors affecting to proper iodized salt utilization amongst the households of Northern Ethiopia.

Methods

Community based cross-sectional designs on selected 318 household food caterers were interviewed and salt samples were accordingly collected. Data was analyzed by the SAS-9.2 statistical software package. The iodine concentrations of the salt samples were determined by using the golden standard iodometric titration technique. Logistic Generalized Estimating Equation (GEE) statistical analysis method was used to assess factors affecting proper iodized salt utilization at household level.

Results

Adequately iodized salt coverage among the households was only 51 (17.5%). About 42 (14.38%) had 15 ppm (ppm) – 80 ppm, 9 (3.08%) had > 80 ppm, 188 (64.4%) had 1.1 ppm to 14.9 ppm and 53 (18.2%) had no iodine in the salt (0 ppm). Only 26 (8.9%) of the households had used iodized salt properly. Family size with Adjusted Odds Ratio (AOR) (0.82) and 95%CI [0.67, 0.92], residency of the household with AOR (2.83) and 95%CI [1.48, 5.40], the availability of iodized salt with AOR (3.90) and 95% CI [1.74, 8.7] and affordability to iodized salt with AOR (3.33) and 95% CI [1.41, 7.34] was strong predictors to proper iodized salt utilization.

Conclusions

Coverage of adequately iodized salt was low. Family size, residency, availability and affordability of iodized salt were the predictors of proper iodized salt utilization. To enhance USI utilization effective inspection and regulatory measures should be taken to prevent the production and distribution of under/ over iodized salt in the market.

Electronic supplementary material

The online version of this article (10.1186/s40795-019-0291-x) contains supplementary material, which is available to authorized users.

Nutritional status of iodine in children: When appropriateness relies on milk consumption and not adequate coverage of iodized salt in households

BACKGROUND & AIMS

Iodine deficiency inhibits the normal development of human beings and is the leading cause of preventable mental retardation. Our study aims to update the urinary iodine concentrations and the intake of iodized salt in children in Madrid (Spain).

METHODS

A cross-sectional study was designed where 217 children aged 3-14 years old were studied. A nutritional survey including the intake of iodized salt and other iodine-rich foods was performed. In addition, the urinary concentration of iodine was determined in each patient.

RESULTS

Near 60% of the surveyed households routinely used iodized salt. Significant differences in age, sex, country of birth, or country of birth and parents educational levels and iodized salt consumption were not found. The median of the urinary iodine level (120 μg/L; interquartile range 80-184) was significantly higher in boys than girls and more elevated in younger children. Iodized salt and milk consumption significantly increased the concentration of urinary iodine. Children who drank less than two glasses of milk per day and did not consume iodized salt have four times the risk of iodine deficiency compared to children who daily drank at least two glasses of milk and consumed iodized salt (P < 0.001).

CONCLUSIONS

The nutritional level of iodine in the children studied is appropriate despite the low consumption of iodized salt. This is due to the consumption of dairy products and milk. The younger the child, the better his/her iodine nutritional level. Teenagers studied are at higher risk of iodine deficiency.

Iodine status, and knowledge about iodine deficiency disorders in adolescent school girls aged 14-19 years, 2016

Background: Adequate iodine intake by women in child-bearing age affects fetus neurodevelopment during pregnancy. A majority of previous studies has investigated iodine status among children, and there is limited data on female adolescents who are more exposed to consequences of iodine deficiency (ID) in their near-future pregnancies; thus, we aimed to assess iodine status, and knowledge on iodine deficiency disorders (IDDs) among adolescent school girls (14-19 years old) in Shahriar, Iran. Methods: This cross-sectional study was conducted among 223 female students selected through multi-stage cluster sampling from 12 schools. Iodine and creatinine concentrations were measured in casual urine samples. Iodine content of household salts was also assessed.Data on intake of salt and iodine-rich food sources were collected applying a food frequency questionnaire (FFQ), and knowledge about iodine and IDDs were assessed by a questionnaire. Results: Median and Mean (95% CI) concentrations of urinary iodine and creatinine were 129 µg/L, 137.62 µg/L (95% CI: 126.28, 148.95) and 1.72 g/L, 1.86 g/L (95% CI: 0.55-3.17),respectively. The frequency of mild, moderate and severe ID were 22.4%, 14.3% and 0%,respectively; 43.5% had adequate, and 3.1% had excessive urinary iodine levels. Mean saltiodine concentration was 21.69 (SD=10.56) ppm. Mean knowledge score was 12.7 (SD=3.44).About half of the students had a poor (25.1%) or fair (24.2%) knowledge about iodine deficiency.Adjusting for the confounders, no significant positive association was found between knowledge about iodine-rich food sources and goitrogens with urinary iodine excretion. Conclusion: Adolescent girls in Shahriar had relatively poor knowledge of iodine, and about one third of them suffered from ID.

Knowledge and practice of iodized salt utilization among reproductive women in Addis Ababa City

OBJECTIVE

The objective of this study was to assess knowledge and practice of iodized salt utilization among reproductive women in Addis Ababa city. A cross-sectional study was carried out on 549 households. A sample district was designated by using the simple random sampling techniques. Data were collected by a face-to-face interview and household salt was tested to check whether its practice was good. p < 0.2 in the bivariate logistic regression was entered into the multivariable logistic regression, and p < 0.05 was considered as significantly associated.

RESULTS

Mothers who had good knowledge and practice of iodized salt were 78% (95% CI 74.9, 81.2) and 76.3% (95% CI 72.7, 79.8), respectively. Monthly household income (AOR = 2.97; 95% CI 1.20, 7.37) was associated with knowledge of iodized salt of respondents. Similarly, educational status (AOR = 2.45; 95% CL 2.10, 6.43) of respondents was significantly associated with the practice of iodized salt. This study indicated that increasing the level of knowledge and practice of iodized salt was good. Monthly household income and educational status were associated with knowledge and practices of iodized salt of respondents. Hence, improving mothers' education is a highly recommended strategy for addressing public health problems of iodine deficiency.

Availability of adequately iodized salt at household level in Dessie and Combolcha Towns, South Wollo, Ethiopia

Background

Iodine deficiency disorder is the leading cause of mental retardation and poor economic performance in developing countries. Worldwide, universal salt iodization has been implemented to eliminate iodine deficiency. However, the adequacy of iodine in salts needs close monitoring to meet its intended goal and this study was aimed at investigating the adequacy of iodine in dietary salt at household level in Dessie and Combolcha Towns.

Methods

A community-based cross-sectional study was employed at household level in Dessie and Combolcha towns from January to February, 2017. Data were collected from 753 households using systematic sampling technique. The adequacy of iodine in salt was analyzed using rapid testing kit. Socio-demographic and economic, dietary sources, labeling, packaging, storage and cooking methods of household’s characteristics were collected via questionnaire developed using open data kit tool and STATA version 12 was used for further statistical analysis. Ordinal Logistic regression was performed to assess associations between explanatory variables and the response variable.

Results

Nearly one-thrid (31.2%) of the households used inadequate iodized salt, which was below the World Health Organization recommendation level (≥15 ppm at the household level). Most of the respondents from Combolcha town (64.6%) were affected by inadequate use of iodized salt as compared to Dessie Town residents (22.2%). Being Dessie resident (OR = 2.53; 95% CI: 1.31–4.90), households with better socioeconomic status (OR = 2.54; 95% CI:1.10–5.87), site of labeling and packing (salt from open market (OR = 0.10; 95% CI: 0.04–0.23) and no exposure to sunlight (OR = 2.54; 95% CI:1.31–4.91) were the predictors of adequacy of iodized salt at household level.

Conclusions

Availability of adequately iodized salt at the household level in the study area was low. There should be regular quality control and regulatory enforcement of salt iodization at production, labeling and packaging sites of small scale industries and at household level.

Continuously sustained elimination of iodine deficiency: a quarter of a century success in the Islamic Republic of Iran

BACKGROUND

Iodine deficiency and related disorders were very common in Iran prior to 1996, when universal salt iodization (USI) was implemented and in 2000 Iran was declared iodine deficiency disorders (IDD) free. The aim of this study was to evaluate the adequacy of iodine intake by Iranian households in all 30 provinces of Iran, a quarter of a century after the intervention.

METHODS

A total of 18,000 school-aged children (8-10 years with mean 8.7 ± 1 year) were included in this study. Urine samples were collected from all children for measurement of urinary iodine excretion and 1800, 210 and 3000 salt samples were randomly collected from the family kitchen, production site of 73 salt factories and distribution circles of 30 provinces, respectively.

RESULTS

The median urinary iodine concentration (UIC) of participants was 161 μg/L. The proportion of children with UIC of, 20-49, 50-99 and ≥ 100 μg/L were 10.3, 15.9 and 73.7%, respectively. The mean (± SD) and median salt iodine values were 28.2 (± 12.6) and 31.7 ppm, at the production site, and 31.5 (± 13.6) and 29.6 ppm at the distribution circles, respectively. About 80% of factory salts had more than 20 ppm iodine. 98% of households consumed iodized salt, 80% had appropriate salt storage, and 83% of the household salts contained ≥ 20 ppm.

CONCLUSIONS

Based on the results of this study, Iranian populations are consuming adequate iodine. The well-maintained and monitored USI program has improved the dietary iodine intakes of the population, and the country has achieved all criteria of a well-controlled IDD program.

Is iodine nutrition in the Spanish pediatric population adequate? Historical review and current situation

Iodine is an essential component of thyroid hormones, and iodine deficit is the leading cause of preventable mental retardation worldwide. Spain was considered iodine-deficient until 2003. Although iodine urinary levels have been in the optimal range in Spain since 2004, the WHO recognizes that our country does not meet the necessary requirements to ensure that the whole population is not at risk of an iodine deficiency disorder. The aim of this article is to review the current iodine status in Spain. Data from several studies emphasize the low consumption of iodized salt at home. Despite the progress made in recent decades, Spanish children are not exempt from suffering an iodine deficiency disorder. Policies that allow for controlling iodine nutrition and promote universal consumption of iodized salt should therefore be implemented.

Effect of iodized salt on organoleptic properties of processed foods: a systematic review

Despite the global recommendation for fortification of salt with iodine, including salt used in food processing, most salt iodization programs have focussed only on iodization of household salt. Food manufacturers are frequently concerned about the potential instability of iodine and changes in organoleptic properties of their products if iodized salt is used instead of non-iodized salt. To address these concerns, this paper provides a comprehensive review of studies conducted to assess the effect of iodized salt on the organoleptic properties of processed foods and condiments. A comprehensive review was conducted of eligible studies identified by searching electronic databases (PubMed, Medline) and open Internet searches for studies examining the effect of salt iodized with either potassium iodide (KI) or potassium iodate (KIO₃) on processed foods. A total of 34 studies on the effect of iodized salt on 38 types of processed foods are summarized. There is no evidence that the use of iodized salt in production of processed foods or condiments causes adverse organoleptic changes that will affect consumer acceptability or product quality. Universal salt iodization is widely recognized as the most cost-effective intervention to eliminate iodine deficiency. Taking into account increases in the proportion of dietary salt consumed through processed foods, and declines in salt consumed as household salt, iodized salt should be used in the production of processed foods as a means of assuring optimal iodine nutrition without the risk of affecting the organoleptic properties of foods.

Prevalence of iodine deficiency and associated factors among pregnant women in Ada district, Oromia region, Ethiopia: a cross- sectional study

BACKGROUND

Maternal iodine deficiency (ID) during pregnancy has been recognized as a major cause of abortion, stillbirth, congenital abnormalities, perinatal mortality and irreversible mental retardation. In Ethiopia limited information is available regarding the epidemiology of maternal ID. The purpose of the present study was to assess the prevalence of iodine deficiency and associated factors among pregnant women in Ada district, Oromia region, Ethiopia.

METHOD

A community based, cross-sectional study was conducted in rural areas of Ada district, October to November, 2014. Data were collected from 356 pregnant women selected by multistage cluster sampling technique. Presence of goiter was examined by palpation and urinary iodine concentration was measured using inductively-coupled-plasma mass spectrometry. Salt iodine concentration was determined using a digital electronic iodine checker. Statistical analysis was done primarily using binary logistic regression. The outputs of the analysis are presented using adjusted odds ratio (AOR) with the respective 95% confidence intervals (CI).

RESULTS

The median urinary iodine concentration (UIC) was 85.7 (interquartile range (IQR): 45.7-136) μg/L. Based on UIC, 77.6% (95% CI: 73.0-82.0%) of the study subjects had insufficient iodine intake (UIC < 150 μg/L). The goiter rate was 20.2% (95% CI: 16.0-24.0%). The median iodine concentration of the household salt samples was 12.2 (IQR: 6.9-23.8) ppm. Of the households, only 39.3% (95% CI: 34.0-44.0%) consumed adequately iodized salt (≥15 ppm). Prevalence of goiter was significantly higher among pregnant women aged 30-44 years (AOR = 2.32 (95% CI: 1.05-5.14)) than among younger women and among illiterate women (AOR = 2.71 (95% CI: 1.54-4.79)). Compared to nulliparous, women with parity of 1, 2 and 3 or more had 2.28 (95% CI: 1.01-5.16), 2.81 (95% CI: 1.17-6.74) and 4.41 (95% CI: 1.58-12.26) times higher risk of goiter.

CONCLUSION

Iodine deficiency was a public health problem in the study area. This indicates the need for further strengthening of the existing salt iodization program in order to avail homogenously and adequately iodized salt. Also it is necessary to find ways to provide iodine supplements as needed until universal salt iodization (USI) is fully established.

Efficacy of educational intervention to improve awareness of the importance of iodine, use of iodized salt, and dietary iodine intake in northeastern Italian schoolchildren

OBJECTIVE

An educational program was conducted among school-aged children to improve their knowledge about iodine prophylaxis, their iodine status, and their dietary habits.

METHODS

At the baseline (T0) and after 6 mo (T1), participants (970 at T0 and 949 at T1) answered questionnaires testing their knowledge about iodine prophylaxis and their eating habits. Urine samples were collected from a randomly selected subgroup of participants (313 at T0 and 312 at T1).

RESULTS

From T0 to T1 there was a significant improvement in respondents' knowledge about iodine prophylaxis (from 44% to 70%), iodized salt consumption (from 78% to 84%), and median urine iodine concentrations (from 70 µg/L to 91 µg/L). Milk and iodized salt intakes were associated with a better iodine status per se, and more so when used simultaneously. Girls drank milk less often than boys did (daily in 52% and 59% of cases, respectively). Children of foreign origin ate sodium-rich food more often than Italians did.

CONCLUSION

Educational intervention improved the children's knowledge about iodine prophylaxis and use of iodized salt. Consuming salt in addition to milk improves iodine status. Children of foreign origin have different eating habits.

Assessment of household use of iodized salt and adequacy of salt iodization: a cross-sectional National Study in Saudi Arabia

Objectives

This study was conducted to assess household coverage with iodized salt in Saudi Arabia, and to determine adequacy of salt iodization.

Methods

A school-based cross-sectional study using WHO 30-cluster survey methodology.

Results

Analysis of 4242 salt samples using qualitative rapid test kit (RTK) revealed that 68.7% (95% CI 67.3–70.1%) were iodized with significant regional differences (p < 0.001). The highest iodized salt samples came from Makkah (82.3%), Riyadh (81.1%) and Maddinah (76.2%) regions, while the least iodized salt samples came from Hail (31.3%), Baha (53.0%), and Northern Borders (57.5%) regions. The national weighted proportion of households consuming iodizes salt was 69.8% (95% CI 69.4–71.2), which is below the Universal Salt Iodization (USI) goal (≥90% coverage). For validation, a quantitative iodometric titration method was used to analyze 775 representative salt samples screened iodized by RTK; iodine content of ≥15 ppm was found in 95.2% (95% CI 93.9–96.5) of samples with median iodine content 51 ppm (mean 50.4 ± 21.8). More than 70% of the iodized salt samples contained iodine concentration higher than the recommended national level (15–40 ppm).

Conclusions

The study revealed inadequate consumption of iodized salt among Saudi households and explored marked regional heterogeneity. The majority of iodized salt samples contained iodine concentration more than the recommended level. These findings imply the need to launch a public awareness campaign on use of iodized salt. Legislation to ban production and sale of non-iodized salt sale for human consumption might be considered. A well-functioning monitoring system at factory level and surveillance system are crucially needed to ensure proper salt iodization and intake.

The bioaccessibility of iodine in the biofortified vegetables throughout cooking and simulated digestion

Biofortification of crops with exogenous iodine is a novel strategy to control iodine deficiency disorders (IDD). The bioaccessibility of iodine (BI) in the biofortified vegetables in the course of soaking, cooking and digestion, were examined. Under hydroponics, the concentration of iodine in leafstalks of the celery and pakchoi increased with increasing exogenous iodine concentration, 54.8-63.9% of the iodine absorbed by pakchoi was stored in the soluble cellular substance. Being soaked in water within 8 h, the iodine loss rate of the biofortified celery was 3.5-10.4% only. More than 80% of the iodine in the biofortified celery was retained after cooking under high temperature. The highest BI of the biofortified vegetables after digestion in simulated gastric and intestinal juice amounted to 74.08 and 68.28%, respectively. Factors influencing BI included pH, digestion duration, and liquid-to-solid ratio. The high BI of the biofortified vegetables provided a sound reference for the promotion of iodine biofortification as a tool to eliminate the IDD.

Has iodized salt reduced iodine-deficiency disorders among school-aged children in north-west Iran? A 9-year prospective study

OBJECTIVE

Low iodine intakes are associated with goitre and other iodine-deficiency disorders (IDD) that have affected billions of people worldwide. We aimed to assess total goitre rate (TGR) and urinary iodine concentration (UIC) in schoolchildren between 2007 and 2015, percentage of iodized salt consumption by households, and salt iodine content at production, distribution and household levels in north-west Iran. Design/Setting/Subjects UIC assessed among schoolchildren in nine consecutive years; 240 schoolchildren aged 8-10 years selected by systematic random sampling each year in the West Azerbaijan Province.

RESULTS

Median UIC was >100 μg/l in all years. More than 50 % of children had iodine deficiency (UIC≤99 μg/l) in 2010 and 2011, while this rate was approximately 15-35 % in other years. Proportion with UIC below 50 μg/l was <20 % in all years except 2010 and 2011. Excessive UIC (≥300 μg/l) rate was between 5·4 and 27·5 %. TGR decreased from 44 % in 1996 to 7·6 % and 0·4 % in 2001 and 2007, respectively. Regular surveys from 2002 to 2015 showed that 98 % or more of households consumed iodized salt. Iodine level ≥20 ppm was observed in 87·5, 83 and 73 % of salt at production, distribution and household level, respectively (data from national study in 2007). The last national study in 2014 showed that median iodine level in household salt was 27 ppm.

CONCLUSIONS

Our focused data suggest that the universal salt iodization programme is improving the iodine status of schoolchildren in the West Azerbaijan Province of Iran. Reduction of TGR to less than 5 % in schoolchildren indicates successful elimination of IDD as a major public health problem.

Availability of adequately iodized in Northwest Ethiopia: a cross-sectional study

Background

Universal salt iodization is the most cost-effective, safe and sustainable strategy to eliminate iodine deficiency disorders. However, little is known about the availability of adequately iodized salt in the northwestern part of Ethiopia. Thus, the aim of this study was to assess the availability of adequately iodized salt at the household level and associated factors in Dabat District, northwest Ethiopia.

Methods

A community-based cross-sectional study was conducted from February 21 to March 31, 2016. We included 705 households in the study. A stratified multistage followed by simple random sampling technique was employed to select households. The level of salt iodine content was determined using the rapid field test kit. Accordingly, the value of <15 parts per million (PPM) and ≥15 PPM with the corresponding color chart on the rapid test kit were used to classify the level of iodine content in the sampled salt. A multivariable binary logistic regression model was fitted to identify factors associated with the availability of adequately iodized salt. Adjusted Odds Ratio (AOR) with the corresponding 95% Confidence Interval (CI) was calculated to show the strength of association.

Results

This study indicated that about 33.2% [95% CI: 29.6, 36.7%] of households had adequately iodized salt. Urban residence (AOR = 2.15, 95% CI: 1.23, 3.76), use of packed salt (AOR = 2.23, 95% CI: 1.01, 4.89), and good respondents' knowledge on iodized salt use (AOR = 1.49, 95% CI: 1.08, 2.08) were positively associated with the availability of adequately iodized salt. However, longer distance to buy salt was inversely related with availability of adequately iodized salt (AOR = 0.68, 95% CI: 0.48, 0.99).

Conclusions

The availability of iodized salt is well under the WHO recommendation in Dabat District in spite of the fact that Ethiopia has been implementing universal salt iodization since the last five years. Therefore, intensifying strategies targeting to enhance community awareness on the benefit and handling practice of iodized salt is essential to improve availability of iodized salt. In addition, the focus needs to be on improving accessibility of iodized salt.

Socio-economic and spatial correlates of subclinical iodine deficiency among pregnant women age 15-49 years in Tanzania

BACKGROUND

Iodine deficiency is a widespread global health problem that affects about 2 billion people each year. Pregnant women are particularly vulnerable to iodine deficiency due to increased iodine requirement leading to death, miscarriage, and stillbirth. Iodine deficiency also has significant negative effects on newborns including impaired cognitive development, impaired learning capabilities, and stunting. This study looks at the association between subclinical iodine deficiency and demographic factors including age, wealth index, education, family size, geographical zone, number of children, fish consumption, pregnancy trimester and household salt in pregnant women aged 15-49 years in Tanzania.

METHODS

The 2010 Tanzania Demographic and Health Survey (TDHS) data was re analysed. Subclinical iodine deficiency is classified as a urinary iodine concentration (UIC) of <150 μg/L.

RESULTS

Results showed that the prevalence of iodine deficiency (54%) was unacceptably high among pregnant women. The results of multiple logistic regression model found that number of children, wealth index, household salt, and geographical zone were significantly associated with iodine deficiency in these women.

CONCLUSION

These results indicate a need to implement interventions to increase iodine intake that targets pregnant women with the specific demographic characteristics.

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 378.9 μg, 379.2 μg and 366.9 μg 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.

Iodine Status of Vulnerable Populations in Henan Province of China 2013-2014 After the Implementation of the New Iodized Salt Standard

The standard of salt iodine content in China has been adjusted several times since implementation of the universal salt iodization (USI) in 1995. The new standard of iodized salt content was adjusted from 35 ± 15 to 30 ± 9 mg/kg in Henan province in 2012. We aimed to determine whether the vulnerable populations were iodine sufficient after the adjustment of salt iodine content and to provide a guideline for the adjustment of USI policy in China. Two cross-sectional surveys of iodine status in vulnerable populations, including reproductive-age, pregnant and lactating women, infants <2 years, and children aged 8-10 years, were conducted in Henan province in 2013 and 2014. In 2013, the median urinary iodine concentration (mUIC) of reproductive-age women was 200.1 μg/L and that of school children aged 8-10 years was 221.0 μg/L. These mUICs were considered as "more than adequate." The mUICs of reproductive-age women and school children in 2014 showed a significant decline compared to the mUICs in 2013 (P = 0.012 and P = 0.001, respectively). The mUICs of the pregnant women were 204.2 μg/L in 2013 and 202.5 μg/L in 2014, which both met the requirement level recommended by WHO. In 2013, the mUIC of lactating women was 169.1 μg/L and that of infants <2 years was 203.2 μg/L, which were significantly lower than that of 2014 (P < 0.001 and P < 0.001, respectively). The lactating women and infants in 2013 and 2014 were both regarded as "iodine adequate." Iodine status of the vulnerable populations is still adequate as a whole in Henan province after decreasing the salt iodine content. However, the mUIC of school children aged 8-10 years is slightly above the adequate level. To reduce the risk of iodine excess in the general population and prevent the possibility of iodine deficiency of the vulnerable population, it is necessary to explore the appropriate level of iodized salt content.

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 mL and 1.50 mL, 2.60 mL and 1.37 mL, 2.63 mL and 1.25 mL, 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.

Assessment of iodine concentration in dietary salt at household level in Morocco

BACKGROUND

Following WHO recommendations, Morocco adopted in 1995 the universal salt iodization (USI) as a strategy to prevent and control iodine deficiency disorders. In 2009, the standard salt iodine concentration was adjusted to 15-40 mg/kg. The success of USI for the control of iodine deficiency disorders requires an evaluation of iodine concentration in salt prior to assessing the iodine nutritional status of a population.

METHODS

In our study we refer to the anterior studies that were made in Morocco in 1993 and 1998. 178 salt samples from households were tested for iodine using spot-testing kits. The iodometric titration method was used to analyze accurately the concentration of iodine in the 178 household salt samples. An empiric polling method was adopted, using a non-probability sampling method; across the different twelve regions in the country.

RESULTS

The median and interquartile range iodine concentration in salt was 2.9 mg/kg (IQR: 2.4-3.7). The results show that only 25 % of households use iodized salt. The recommended iodine concentration in salt of 15-40 mg/kg was met only in 4.5 % of salt samples. The bulk salt is used by 8 % of households. All samples of this bulk salt were found in rural areas. According to nonparametric appropriate tests used, there is no significant difference in iodine concentrations between regions, between urban and rural areas and between packaged and bulk salt.

CONCLUSIONS

Two decades since introducing legislation on Universal Salt Iodization, our survey shows that generalization of iodized salt is far from being reached. In 2015, only a quarter of Moroccan households use the iodized salt and only 4.5 % of salt is in conformity with regulations. The use of bulk salt by households in rural areas constitutes a major obstacle to the success of USI. The National Iodine Deficiency Disorders Control Program can only be achieved if an internal follow-up and a control of external quality of program is put in place.

Performance of rapid test kits to assess household coverage of iodized salt

OBJECTIVE

The main indicator adopted to track universal salt iodization has been the coverage of adequately iodized salt in households. Rapid test kits (RTK) have been included in household surveys to test the iodine content in salt. However, laboratory studies of their performance have concluded that RTK are reliable only to distinguish between the presence and absence of iodine in salt, but not to determine whether salt is adequately iodized. The aim of the current paper was to examine the performance of RTK under field conditions and to recommend their most appropriate use in household surveys.

DESIGN

Standard performance characteristics of the ability of RTK to detect the iodine content in salt at 0 mg/kg (salt with no iodine), 5 mg/kg (salt with any added iodine) and 15 mg/kg ('adequately' iodized salt) were calculated. Our analysis employed the agreement rate (AR) as a preferred metric of RTK performance. Setting/Subjects Twenty-five data sets from eighteen population surveys which assessed household iodized salt by both the RTK and a quantitative method (i.e. titration or WYD Checker) were obtained from Asian (nineteen data sets), African (five) and European (one) countries.

RESULTS

In detecting iodine in salt at 0 mg/kg, the RTK had an AR>90 % in eight of twenty-three surveys, while eight surveys had an AR90 %.

CONCLUSIONS

The RTK is not suited for assessment of adequately iodized salt coverage. Quantitative assessment, such as by titration or WYD Checker, is necessary for estimates of adequately iodized salt coverage.

Effect of reducing iodine excess on children's goiter prevalence in areas with high iodine in drinking water

The purpose of the study was to evaluate the effect of removing iodized salt on children's goiter prevalence in high iodine area (HIA). A total of 452 and 459 children aged 8-10 years old were selected by simple random sampling method before and after removing iodized salt from their diet in three towns with median water iodine content of 150-300 µg/l in Hengshui city of Hebei province of China. Their goiter status was judged using the thyroid volume (Tvol) reference for body surface area recommended by the WHO. After removing iodized salt, children's overall median urinary iodine content (MUIC) decreased from 518 (IQR 347,735) µg/l to 416 µg/l (IQR 274,609). Children's MUIC across sex and age group decreased significantly. The overall goiter prevalence in the three towns significantly decreased from 32.96 % (149/452) to 6.54 % (30/459) (P < 0.001). The goiter prevalence in 8-, 9-, and 10-year-old children decreased, respectively, from 38.04 % (35/92), 30.57 % (59/193), and 32.93 % (55/167) to 6.10 % (10/164), 6.75 % (11/163), and 6.82 % (9/132). The goiter prevalence in boys and girls decreased from 34.01 % (83/244) and 31.73 % (66/208) to 6.19 % (14/225) and 6.87 % (16/234), respectively. The decreases in children's goiter prevalence across gender and age groups were all statistically significant. The present study revealed that children's goiter prevalence decreased significantly after removing iodized salt from their diet for about one and half years in the HIA in Hebei province.

Consumption of iodized salt may not represent a reliable indicator of iodine adequacy: Evidence from a cross-sectional study on schoolchildren living in an urban area of central Italy

OBJECTIVE

It has been established that iodine prophylaxis prevents endemic goiter. In this study we reported the amount of iodized salt sold by the retailers of Cassino, a city of central Italy. The aim of the study was to evaluate the effects of an iodine prophylaxis program started in 2005 on urinary iodine concentration (UIC) and thyroid volume (TV), and their correlation with anthropometric parameters in a population of schoolchildren.

METHODS

The study included 234 schoolchildren (119 girls and 115 boys) ages 13 to 14 y. Each student provided a morning urine sample for UIC determination, and TV was evaluated by ultrasonography. Body weight and height also were measured. Each participant completed a questionnaire reporting the presence of thyroid disease and the consumption of iodized salt and iodine-rich food.

RESULTS

The percentage of iodized salt sold by local markets was 42.4%. Median UIC in schoolchildren was 133.9 μg/L (range 33.2-819.5 μg/L), with 71 children having mild (range 50.1-99.9 μg/L) and 10 moderate (range 33.2-48.8 μg/L) iodine deficiency. Eleven children showed excessive iodine intake (range 300.4-819.5 μg/L). Median UIC was higher in children using iodized salt or consuming milk. Goiter prevalence was 3.8%. A positive correlation between TV and body weight, height, and surface was observed.

CONCLUSIONS

The data reported may suggest the presence of an adequate iodine intake in the population of Cassino despite the low percentage of iodized salt sold by local retailers. This indicates that silent iodine prophylaxis through the consumption of iodine-rich or iodine-enriched food is of importance in the prevention of iodine deficiency disorders.

Assessment of iodine nutritional status in the general population in the province of Jaén

BACKGROUND AND OBJECTIVE

Iodine deficiency affecting both pregnant women and schoolchildren has been reported in Jaén. Iodine deficiency is one of the leading causes of thyroid dysfunction and goiter, and adequate iodine prophylaxis with iodized salt, milk, and dairy products, or iodine supplementation have been shown to significantly improve iodine status in pregnancy. The purpose of this study was to assess iodine nutritional status in the general population of a iodine-deficient area with no previous institutional campaigns of iodine prophylaxis.

MATERIAL AND METHODS

A descriptive, cross-sectional study. Urinary iodine levels were measured in subjects from the Jaén healthcare district. The data were stratified by sex and age groups, and a survey was conducted on iodized salt consumption.

RESULTS

Median and mean urinary iodine levels were 110.59 mcg/L and 130.11 mcg/L respectively. Urinary iodine levels were significantly higher in schoolchildren as compared to other age groups (161.52μg/L vs 109.33μg/L in subjects older than 65 years). Forty-three percent of the population had urinary iodine levels less than 100μg/L, and 68% of women of childbearing age had levels less than 150μg/L.

CONCLUSIONS

Iodine nutritional status appears to be adequate, but the proportion of the population with urinary iodine levels less than 100μg/L is still very high, and iodized salt consumption is much less common than recommended by the WHO.

Iodine intake as a risk factor for thyroid cancer: a comprehensive review of animal and human studies

Thyroid cancer (TC) is the most common endocrine malignancy and in most countries, incidence rates are increasing. Although differences in population iodine intake are a determinant of benign thyroid disorders, the role of iodine intake in TC remains uncertain. We review the evidence linking iodine intake and TC from animal studies, ecological studies of iodine intake and differentiated and undifferentiated TC, iodine intake and mortality from TC and occult TC at autopsy, as well as the case–control and cohort studies of TC and intake of seafood and milk products. We perform a new meta-analysis of pooled measures of effect from case–control studies of total iodine intake and TC. Finally, we examine the post-Chernobyl studies linking iodine status and risk of TC after radiation exposure. The available evidence suggests iodine deficiency is a risk factor for TC, particularly for follicular TC and possibly, for anaplastic TC. This conclusion is based on: a) consistent data showing an increase in TC (mainly follicular) in iodine deficient animals; b) a plausible mechanism (chronic TSH stimulation induced by iodine deficiency); c) consistent data from before and after studies of iodine prophylaxis showing a decrease in follicular TC and anaplastic TC; d) the indirect association between changes in iodine intake and TC mortality in the decade from 2000 to 2010; e) the autopsy studies of occult TC showing higher microcarcinoma rates with lower iodine intakes; and f) the case control studies suggesting lower risk of TC with higher total iodine intakes.

Iodine status from childhood to adulthood in females living in North-East Italy: Iodine deficiency is still an issue

PURPOSE

This survey aimed to assess iodine status in a female population at different ages, also investigating their eating habits.

METHODS

We measured urinary iodine concentrations (UIC) in: 634 females at puberty and 361 fertile women in 246 of whom were considered also their children (134 daughters and 120 sons). All subjects completed a food frequency questionnaire.

RESULTS

Median UIC decreased from childhood to adulthood (median UIC 107, 77 and 55 μg/l in the young girls, females at puberty and fertile women, respectively). Though using iodized salt improved iodine status in all groups, a significantly higher UIC was only noted in females at puberty. Milk consumption significantly increased UIC at all ages. In mother-child (both daughters and sons) pairs, the children's median UIC was nearly twice as high as their mothers' (UIC 115 vs. 57 μg/l). Milk consumption varied significantly: 56% of the mothers and 76% of their children drank milk regularly. The children (both daughters and sons) and mothers who drank milk had UIC ≥100 μg/l in 59 and 34% of cases, respectively, among the pairs who did not drink milk, 44% of the children and 19% of the mothers had UIC ≥100 μg/l. On statistical regression, 3.6% of the variability in the children's UIC depended on that of their mothers.

CONCLUSIONS

Dietary iodine status declines from childhood to adulthood in females due to different eating habits. A mild iodine deficiency emerged in women of child-bearing age that could have consequences during pregnancy and lactation.

Prevalence of iodine inadequacy in Switzerland assessed by the estimated average requirement cut-point method in relation to the impact of iodized salt

OBJECTIVE

To assess the iodine status of Swiss population groups and to evaluate the influence of iodized salt as a vector for iodine fortification.

DESIGN

The relationship between 24 h urinary iodine and Na excretions was assessed in the general population after correcting for confounders. Single-day intakes were estimated assuming that 92 % of dietary iodine was excreted in 24 h urine. Usual intake distributions were derived for male and female population groups after adjustment for within-subject variability. The estimated average requirement (EAR) cut-point method was applied as guidance to assess the inadequacy of the iodine supply.

SETTING

Public health strategies to reduce the dietary salt intake in the general population may affect its iodine supply.

SUBJECTS

The study population (1481 volunteers, aged ≥15 years) was randomly selected from three different linguistic regions of Switzerland.

RESULTS

The 24 h urine samples from 1420 participants were determined to be properly collected. Mean iodine intakes obtained for men (n 705) and women (n 715) were 179 (sd 68.1) µg/d and 138 (sd 57.8) µg/d, respectively. Urinary Na and Ca, and BMI were significantly and positively associated with higher iodine intake, as were men and non-smokers. Fifty-four per cent of the total iodine intake originated from iodized salt. The prevalence of inadequate iodine intake as estimated by the EAR cut-point method was 2 % for men and 14 % for women.

CONCLUSIONS

The estimated prevalence of inadequate iodine intake was within the optimal target range of 2-3 % for men, but not for women.