Iodine intake in the Swiss population 100 years after the introduction of iodised salt: a cross-sectional national study in children and pregnant women.

PURPOSE: The Swiss voluntary salt iodisation programme has successfully prevented iodine deficiency for 100 years, but dietary habits are changing and today only one-third of processed foods contain iodised salt. We aimed to monitor the current iodine status in children and pregnant women. METHODS: We conducted a nationwide cross-sectional study in children (6-12 years) and pregnant women and measured the urinary iodine concentration (UIC) in spot urine samples. We estimated the iodine intake using UIC and urinary creatinine concentration (UCC) and determined the prevalence of intakes below the average requirement (AR) using the SPADE method. We measured dried blood spot (DBS) thyroglobulin (Tg), TSH and total T4 in pregnant women. RESULTS: The median UIC was 127 µg/L (bootstrapped 95% CI 119, 140, n = 362) in children and 97 µg/L (bootstrapped 95% CI 90, 106, n = 473) in pregnant women. The estimated prevalence of inadequate iodine intake (< 65 µg/day) was 5.4% (bootstrapped 95% CI 0.0, 14.6) in children. Half (47%) of the women consumed iodine-containing multivitamin and mineral supplements (≥ 150 µg/day). Compared to non-users, users had higher median UIC (129 vs. 81 µg/L, P < 0.001), lower prevalence of inadequacy (< 160 µg/day; 0.2 vs. 31%) and lower DBS-Tg (23 vs. 29 µg/L, P < 0.001). All women were euthyroid. CONCLUSIONS: The Swiss diet and current salt fortification provides adequate iodine intake in children, but not in all pregnant women. Iodine supplements cover the dietary gap in pregnancy but are not universally consumed. Therefore, improved use of iodised salt in processed foods is desired to ensure adequate iodine intake in all population groups. This trial was registered at clinicaltrials.gov as NCT04524013.

Prevalence and determinants of goitre among children of South Kordofan state, Sudan, 2021: an urgent need for effective implementation of universal salt iodisation.

OBJECTIVE: This study aimed to determine the prevalence and determinants of goitre among children aged 6-12 years at South Kordofan state. DESIGN: This was a cross-sectional facility-based study. SETTING: The study was conducted in twenty villages of South Kordofan state during a medical mission. PARTICIPANTS: All 575 school-age children (6-12 years) who attended the medical day were examined for clinical assessment of goitre. RESULTS: The prevalence of goitre among children of South Kordofan was 42·8 % (grade 1: 15·7 %, grade 2: 27·1 %). Only 24·2 % of caregivers reported using iodised salt. Mothers working as farmers (OR: 3·209, CI 95 % 1·437, 7·167; P = 0·004) and children of Darforian tribes (OR: 21·799, CI 95 % 2·566, 185·226; P = 0·005) were found to be significantly associated with higher prevalence of goitre among children. This contrasts with children of African tribes, where they were found to have less goitre prevalence (OR: 0·432, CI 95 % 0·213, 0·875; P = 0·02). Iodised salt utilisation (OR = 0·523, CI 95 % 0·320, 0·854; P = 0·01) was found associated with a lower prevalence of goitre. CONCLUSION: Even though National Iodine Deficiency Disorders control programs were initiated in Sudan more than 25 years ago, the prevalence of goitre among children in South Kordofan state was alarming (42·8 %). Efforts to improve access to iodised salt, increase utilisation and raise awareness are urgently needed.

Assessment of iodine nutrition of schoolchildren in Gonda, India, indicates improvement and effectivity of salt iodisation.

OBJECTIVE: To study the total goitre rate (TGR), urinary iodine concentration (UIC) and salt iodine content among schoolchildren in a previously endemic area for severe iodine deficiency disorder (IDD). DESIGN: Cross-sectional epidemiological study. SETTING: The study was carried out in the Gonda district (sub-Himalayan region) of North India. PARTICIPANTS: Nine hundred and seventy-seven schoolchildren (6-12 years) were studied for parameters such as height, weight, UIC and salt iodine content. Thyroid volume (TV) was measured by ultrasonography to estimate TGR. RESULTS: The overall TGR in the study population was 2·8 % (95 % CI 1·8, 3·8). No significant difference in TGR was observed between boys and girls (3·5 % v. 1·9 %, P = 0·2). There was a non-significant trend of increasing TGR with age (P = 0·05). Median UIC was 157·1 µg/l (interquartile range: 94·5-244·9). At the time of the study, 97 % of salt sample were iodised and nearly 86 % of salt samples had iodine content higher than or equal to 15 part per million. Overall, TGR was significantly lower (2·8 % v. 31·0 %, P < 0·001), and median UIC was significantly higher (157·1 v. 100·0 µg/l, P < 0·05) than that reported in the same area in 2009. CONCLUSIONS: A marked improvement was seen in overall iodine nutrition in the Gonda district after three and a half decades of Universal Salt Iodisation (USI). To sustainably control IDD, USI and other programmes, such as health education, must be continuously implemented along with putting mechanisms to monitor the programme at regular intervals in place.

Effectiveness of increased salt iodine concentration on iodine status: trend analysis of cross-sectional national studies in Switzerland.

PURPOSE: Despite longstanding voluntary salt iodisation in Switzerland, data suggest inadequate iodine intake in vulnerable population groups. In response, the salt iodine concentration was increased from 20 to 25 mg/kg and we assessed the impact on iodine status. METHODS: We conducted a cross-sectional national study in school-age children (n = 731), women of reproductive age (n = 353) and pregnant women (n = 363). We measured urinary iodine concentration (UIC) and urinary sodium concentration (UNaC) in spot urine samples. The current median UIC was compared with national data from 1999, 2004 and 2009. We measured TSH, total T4 and thyroglobulin (Tg) on dried blood spot samples collected in women. RESULTS: The median UIC (bootstrapped 95% CI) was 137 µg/L (131, 143 µg/L) in school children, 88 µg/L (72, 103 µg/L) in women of reproductive age and 140 µg/L (124, 159 µg/L) in pregnant women. Compared to 2009, the median UIC increased modestly in school children (P < 0.001), but did not significantly change in pregnant women (P = 0.417). Estimated sodium intake exceeded the recommendations in all population groups. The prevalence of thyroid disorders in women was low, but Tg was elevated in 13% of the pregnant women. CONCLUSION: Iodine intake is overall adequate in Swiss school-age children, but only borderline sufficient in pregnant and non-pregnant women, despite high salt intakes and satisfactory household coverage with iodized salt. Our findings suggest increasing the concentration of iodine in salt may not improve iodine intakes in women if iodised salt is not widely used in processed foods. REGISTRATION: This trial was registered at clinicaltrials.gov as NCT02312466.

Assessment of thyroid function in children, adults and pregnant and lactating women after long-term salt iodisation measurements.

Universal salt iodisation (USI) has been successfully implemented in China for more than 15 years. Recent evidence suggests that the definition of 'adequate iodine' (100-199 µg/l) be revised to 'sufficient iodine' (100-299 µg/l) based on the median urinary iodine concentration (MUI) in school-age children. The objective of this study was to determine the prevalence of thyroid dysfunction in populations after long-term salt iodisation and examine whether the definition of adequate iodine can be broadened to sufficient iodine based on the thyroid function in four population groups. A cross-sectional survey was conducted in six provinces in the northern, central and southern regions of China. Four population groups consisting of 657 children, 755 adults, 347 pregnant women and 348 lactating women were recruited. Three spot urinary samples were collected over a 10-d period and blood samples were collected on the 1st day. In the study, among the adults, pregnant women and lactating women, the prevalence rates of elevated thyroglobulin antibody and thyroid microsomal antibody levels were 12·4, 8·5 and 7·8 %, and 12·1, 9·1 and 9·1 %, respectively. Abnormally high thyroid dysfunction prevalence was not observed after more than 15 years of USI in China because the thyroid dysfunction rates were all <5 %. The recommended range should be cautiously broadened from adequate iodine to sufficient iodine according to the MUI of school-age children considering the high levels of hormones and antibodies in the other populations. Adults, particularly pregnant women positive for thyroid antibodies, should be closely monitored.

High national and sub-national coverage of iodised salt in India: evidence from the first National Iodine and Salt Intake Survey (NISI) 2014-2015.

OBJECTIVE: The National Iodine and Salt Intake Survey (NISI) 2014-2015 was undertaken to estimate household iodised salt coverage at national and sub-national levels in India. DESIGN: Cross-sectional survey with multistage stratified random sampling. SETTING: India was divided into six geographic zones (South, West, Central, North, East and North-East) and each zone was further stratified into rural and urban areas to yield twelve distinct survey strata. SUBJECTS: The target respondent from each household was selected as per predefined priority; wife of the household head, followed by women of reproductive age, followed by any adult available during the visit. RESULTS: Households (n 5717) were surveyed and salt samples (n 5682) were analysed. Household coverage of iodised salt (iodine≥5 ppm) was 91·7 (95 % CI 91·0, 92·7) %. Adequately iodised salt (iodine≥15 ppm) was consumed in 77·5 (95 % CI 76·4, 78·6) % of households. Significant differences in coverage were seen across six geographic regions, with North and North-East zones on the verge of achieving the universal salt iodisation target of >90 % coverage. Coverage of households with adequately iodised salt (adjusted OR; 95 % CI) was significantly less in rural households (0·55; 0·47, 0·64), lower/backward castes (0·84; 0·72, 0·98), deprived households (0·72; 0·61, 0·85) as assessed by multidimensional poverty index, households with non-diverse diet (0·73; 0·62, 0·86) and households using non-packaged salt (0·48; 0·39, 0·59) and non-refined salt (0·17; 0·15, 0·20). CONCLUSIONS: India is within striking reach of achieving universal salt iodisation. However, significant differentials by rural/urban, zonal and socio-economic indicators exist, warranting accelerated efforts and targeted interventions for high-risk groups.

A study on the influencing factors of urinary iodine concentration and the relationship between iodised salt concentration and urinary iodine concentration.

The aim of the present study was to explore the influencing factors of urinary iodine concentration (UIC) and the relationship between iodised salt concentration and UIC in order to give suggestions for the surveillance of iodine nutrition status. For this purpose, a multi-stage cluster sampling technique was employed in the present cross-sectional study. Correlations between UIC and salt iodine concentration were evaluated by Spearmen's correlation analysis. Risk factors of having a lower UIC were identified by logistic regression analysis, and the equations of UIC and salt iodine concentration were fitted by curve regression analysis. The median UIC was found to be 162·0 (25th-75th percentile 98·2-248·6) µg/l. The UIC was correlated with salt iodine concentration (Spearman's ρ = 0·144, P< 0·05). The multiple logistic regression analysis found the following influencing factors for having a lower UIC: age (OR 0·98, 95% CI 0·98, 0·98, P< 0·05); sex (OR 0·81, 95% CI 0·71, 0·92, P< 0·05); education level (OR 0·87, 95% CI 0·83, 0·90, P< 0·05); status of occupation (OR 0·91, 95% CI 0·86, 0·96, P< 0·05); occupation (OR 1·03, 95% CI 1·00, 1·05, P< 0·05); pickled food (OR 1·24, 95% CI 1·08, 1·42, P< 0·05); salt iodine concentration (OR 1·03, 95% CI 1·02, 1·03, P< 0·05). The curve regression analysis found that UIC (y) and salt iodine concentration (x) could be expressed by the following equation: y= 1·5772x 1·4845. In conclusion, the median UIC of individuals in Zhejiang Province falls within optimal status as recommended by the WHO/UNICEF/International Council for Control of IDD. To maintain optimal iodine nutrition status, salt iodine concentration should be in the range of 16·4 to 34·3 mg/kg.

Towards universal salt iodisation in India: achievements, challenges and future actions.

India is one of the first countries to introduce salt iodisation, but the national programme has experienced major setbacks. The purpose of this paper is to review the national efforts towards universal salt iodisation (USI) in India and highlight key challenges in programme implementation. A brief historical overview of the salt iodisation programme is provided and the current status of the household usage of iodised salt and population iodine status is described. The present status of the USI programme together with the challenges being faced towards achieving USI are classified in five categories, which represent the five guiding principles crucial to sustained USI programme success: ensuring political commitment, forming partnerships and coalition, ensuring availability of adequately iodised salt, strengthening the monitoring system and maintaining continuous advocacy, education and communication. A future agenda towards the achievement of USI is also proposed.

Maternal and neonatal iodine status in Dakshina Kannada district of Karnataka, India.

This study was designed to assess iodine status of mother-fetus dyad by estimation of spot urine iodine concentration (UIC) in the study district. It is a cross-sectional study of 250 pregnant women with euthyroid status and their term neonates residing in Dakshina Kannada district. Neonates with foetal growth restriction or requiring intensive care were excluded. Median UIC was quantified using modified Sandell-Kolthoff reaction by microplate method. World Health Organization (WHO) classification was used to categorise the iodine status of pregnant women. Among 250 pregnant women, the majority were primigravida (38%). Median maternal thyroid stimulating hormone (TSH) was 1.54 mIU/l, and median UIC was 352 mcg/l. Urine iodine levels were insufficient (<150 mcg/l) in 1.2% (n = 3), adequate (150-249 mcg/l) in 9.2% (n = 23) and above requirement (250-499 mcg/l) in 89.6% (n = 224); none had excess (> 500 mcg/l). Median birth weight was 3,000 g and head circumference was 34 cm. Median cord blood TSH was 8.1 mIU/l, and median UIC 344.5 mcg/l. All the newborns had adequate (> 100 mcg/l) iodine status, including those born to mothers with insufficient values. Maternal and newborn median UIC showed positive correlation (r = 0.139; p = 0.028). Iodine statuses were above requirement or adequate in pregnant women from the study district and their neonates, respectively, indicating successful salt iodisation.

Monitoring of salt iodisation programme in Iran; Health outcomes, shortages and perspective.

Iodine deficiency disorders include a wide range of metabolic and nonmetabolic disorders including goiter. To control IDDs, the World Health Organization and responsible agencies in countries established daily iodine uptake. Almost all the countries in the world provide the required iodine through salt iodisation. IDDs are not completely eradicable, so monitoring the salt iodisation programme is necessary for control of IDDs. In Iran, a salt iodisation programme was started in 1996. In this study, we took salt samples from all legally produced salt brands in Iran in 30 provinces and measured iodine concentration. The results of the monitoring programme for iodine concentration in schoolchildren's urine was used to compare accessibility to iodized salts and health outcomes. The results show that more than 80% of available salts have a suitable or acceptable concentration of iodine. Despite large variance in iodine concentration in available salt in some provinces, the median of iodine concentration in salts is within an acceptable range. Also, the urinary concentration of iodine (national median = 161) confirms that shortage of iodine intake is very low in Iran. The high rate of salt consumption of the Iranian people also has a significant effect on iodine uptake, but can lead to hyperthyroidism and hypertension that must be controlled.

Iodine Status and Iodised Salt Consumption in Portuguese School-Aged Children: The Iogeneration Study.

The World Health Organization promotes salt iodisation to control iodine deficiency. In Portugal, the use of iodised salt in school canteens has been mandatory since 2013. The present study aimed to evaluate iodine status in school-aged children (6-12 years) and to monitor the use of iodised salt in school canteens. A total of 2018 participants were randomly selected to participate in a cross-sectional survey in northern Portugal. Children's urine and salt samples from households and school canteens were collected. A lifestyle questionnaire was completed by parents to assess children's eating frequency of iodine food sources. Urinary iodine concentration (UIC) was measured by inductively coupled plasma-mass spectrometry. The median UIC was 129 µg/L which indicates the adequacy of iodine status and 32% of the children had UIC < 100 µg/L. No school canteen implemented the iodised salt policy and only 2% of the households were using iodised salt. Lower consumption of milk, but not fish, was associated with a higher risk of iodine deficiency. Estimation of sodium intake from spot urine samples could be an opportunity for adequate monitoring of population means. Implementation of iodine deficiency control policies should include a monitoring program aligned with the commitment of reducing the population salt intake.

Status of iodine nutrition among pregnant mothers in selected districts of Uttarakhand, India.

BACKGROUND: Uttarakhand state is a known endemic area for iodine deficiency. OBJECTIVE: The present study was conducted with an objective to assess the iodine nutritional status amongst pregnant mothers (PMs) in districts: Pauri (P), Nainital (N) and Udham Singh Nagar (USN) of Uttarakhand state. MATERIALS AND METHODS: Thirty clusters from each district were selected by utilizing the population proportionate to size cluster sampling methodology. A total of 1727 PMs from P (481), N (614) and USN (632) were included. The clinical examination of the thyroid of each PM was conducted. Urine and salt samples were collected from a sub samples of PMs enlisted for thyroid clinical examination. RESULTS: The total Goiter rate was found to be 24.9 (P), 20.2 (N) and 16.1 (USN)%. The median urinary iodine concentration (UIC) levels were found to be 110 µg/L (P), 117.5 µg/L (N) and 124 µg/L (USN). The percentage of PMs consuming salt with iodine content of 15 ppm and more was found to be 57.9 (P), 67.0 (N) and 50.3 (USN). CONCLUSION: The findings of the present study revealed that the PMs in all three districts had low iodine nutritional status as revealed by UIC levels of less than 150 µg/L.

Thyroid and iodine nutritional status: a UK perspective.

Iodine is an essential component of the thyroid hormones, which play a crucial role in brain and neurological development. At least one-third of the world's population is estimated to be iodine deficient predominantly in developing countries. Recently concern had also been expressed about the iodine status in industrialised countries such as the UK. A recent survey of the UK iodine status found that that more than two-thirds of schoolgirls aged 14-15 years were iodine deficient due to the reduced milk intake. Maternal iodine deficiency in pregnancy is correlated with cognitive outcomes such as intelligence quotient and reading ability in offspring. No randomised trial data exist for iodine supplementation in mild-moderate iodine-deficient pregnant women. It is possible to combine population interventions to reduce population salt intake with salt iodisation programmes in order to maintain adequate levels of iodine nutrition.

Food Fortification in Indonesia

The paper highlights the history, policy, programs of food fortification intervention and its impact on reducing micronutrient deficiency, especially iodine deficiency disorders (IDD), iron deficiency anaemia (IDA), and vitamin A deficiency (VAD) in Indonesia. General issues in the management of food fortification, and lessons learned from the Indonesian experience are discussed in this paper.