Current iodine status in Japan: A cross-sectional nationwide survey of schoolchildren, 2014–2019

2021 ◽  
Author(s):  
Yozen Fuse ◽  
Yoshiya Ito ◽  
Yoshimasa Shishiba ◽  
Minoru Irie
Keyword(s):  
Urinary Iodine ◽  
Nationwide Survey ◽  
Iodine Concentration ◽  
Iodine Intake ◽  
Urinary Iodine Excretion ◽  
Urinary Iodine Concentration ◽  
Cross Sectional ◽  
Iodine Status ◽  
Iodine Excretion ◽  
Cr Concentration

Abstract Context Japan has been regarded as a long-standing iodine sufficient country without iodine fortification; however, data on nationwide iodine status is lacking. Objective This study aimed to characterize the iodine status in Japan. Methods From 2014 through 2019 a nationwide school-based survey was conducted across all districts in Japan. Urinary iodine concentration (UIC), creatinine (Cr) concentration and anthropometry were assessed in healthy school-aged children (SAC) aged 6 to 12 years. Their iodine status is regarded as generally representative of the nation's iodine status. Results A total of 32,025 children participated. The overall median UIC was 269 μg/L which was within the WHO’s adequacy range. There was a regional difference in UIC values within 14 regions, and the lowest and highest median UIC were found in Tanegashima Island (209 μg/L) and Nakashibetsu, Hokkaido (1,071 μg/L), respectively. The median UIC ≥ 300 μg/L was observed in 12 out of 46 regions. By using estimated 24-h urinary iodine excretion (UIE), the prevalence of SAC exceeding the upper tolerable limit of iodine for Japanese children was from 5.2 to 13.7%. The UIC values did not change with age, BSA and BMI percentile, while the Cr concentration simultaneously increased suggesting the effect of urinary creatinine on UI/Cr and estimated 24-h UIE values. Conclusions The iodine intake of Japanese people is adequate, but in some areas it is excessive. The incidence and prevalence of thyroid disorders associated with iodine intake should be obtained especially in the areas where high amounts of iodine are consumed.

scholarly journals Urinary iodine excretion in urine samples among children in Dang district, Gujarat

2017 ◽  
Vol 4 (7) ◽  
pp. 2339
Author(s):  
Rahul Damor ◽  
Jatin Chhaya ◽  
Sukesha Gamit ◽  
Jayant Patel ◽  
J. K. Kosambiya
Keyword(s):  
Iodine Deficiency ◽  
Primary Schools ◽  
Urinary Iodine ◽  
Human Growth ◽  
Iodine Intake ◽  
Urine Samples ◽  
Urinary Iodine Excretion ◽  
Urinary Iodine Concentration ◽  
Cross Sectional ◽  
Iodine Excretion

Background: Iodine is an essential micronutrient required for normal human growth and development as it is needed for the synthesis of thyroid hormones produced by thyroid glands. The sicknesses occurred due to deficiencies of iodine in the nutrition are termed iodine deficiency disorders. Urinary iodine concentration is the prime indicator of a person’s nutritional iodine status. So, the aim of this study was to assess the status of iodine deficiency based on median urinary iodine excretion.Methods: Community based cross sectional study was carried out among purposively selected primary schools of the Dang district. All students between the age group of 6 to 12 years who were present on the day of visit were included in the study. A total 387 urine samples were collected during the period of August 2015 to September 2016.Results: Based on median urinary iodine excretion, among total analysed samples, about 6.5% samples confirmed severe iodine deficiency, 22% samples showed moderate iodine deficiency and about 36% samples indicated mild iodine deficiency. About one third (31.3%) samples suggested optimum iodine intake. Only few samples (4.4%) revealed more than required iodine intake.Conclusions: About one third (31.3%) of the surveyed population had adequate iodine intake while majority (64.4%) of them had inadequate iodine intake. 

Intra-individual and inter-individual variations in iodine intake and excretion in adult women: implications for sampling

2019 ◽  
Vol 123 (9) ◽  
pp. 987-993 ◽  
Author(s):  
Wen Chen ◽  
Shu Gao ◽  
Wenxing Guo ◽  
Long Tan ◽  
Ziyun Pan ◽  
...  
Keyword(s):  
Urinary Iodine ◽  
Sampling Period ◽  
Iodine Concentration ◽  
Iodine Intake ◽  
Urine Samples ◽  
Urinary Iodine Excretion ◽  
Urinary Iodine Concentration ◽  
Adult Women ◽  
Individual Variations ◽  
Iodine Excretion

AbstractIodine intake and excretion vary widely; however, these variations remain a large source of geometric uncertainty. The present study aims to analyse variations in iodine intake and excretion and provide implications for sampling in studies of individuals or populations. Twenty-four healthy women volunteers were recruited for a 12-d sampling period during the 4-week experiment. The duplicate-portion technique was used to measure iodine intake, while 24-h urine was collected to estimate iodine excretion. The mean intra-individual variations in iodine intake, 24-h UIE (24-h urinary iodine excretion) and 24-h UIC (24-h urinary iodine concentration) were 63, 48 and 55 %, respectively, while the inter-individual variations for these parameters were 14, 24 and 32 %, respectively. For 95 % confidence, approximately 500 diet samples or 24-h urine samples should be taken from an individual to estimate their iodine intake or iodine status at a precision range of ±5%. Obtaining a precision range of ±5% in a population would require twenty-five diet samples or 150 24-h urine samples. The intra-individual variations in iodine intake and excretion were higher than the inter-individual variations, which indicates the need for more samples in a study on individual participants.

Saliva Iodine Concentration in Children and Its Association with Iodine Status and Thyroid Function

2020 ◽  
Vol 105 (9) ◽  
pp. e3451-e3459 ◽  
Author(s):  
Wenxing Guo ◽  
Ziyun Pan ◽  
Ying Zhang ◽  
Ya Jin ◽  
Shuyao Dong ◽  
...  
Keyword(s):  
Thyroid Function ◽  
Primary Schools ◽  
Urinary Iodine ◽  
Reference Value ◽  
Iodine Concentration ◽  
Cross Sectional Study ◽  
Urinary Iodine Excretion ◽  
Urinary Iodine Concentration ◽  
Cross Sectional ◽  
Iodine Status

Abstract Context The effectiveness of saliva iodine concentration (SIC) in evaluating iodine status in children is not clear. Objective We aimed to explore associations between SIC and assessed indicators of iodine status and thyroid function. Design Cross-sectional study. Setting Primary schools in Shandong, China. Participants Local children aged 8 to 13 years with no known thyroid disease were recruited to this study. Main outcome measures Blood, saliva, and urine samples were collected to evaluate thyroid function and iodine status. Results SIC positively correlated with spot urinary iodine concentration (r = 0.29, P < 0.0001), 24-hour urinary iodine concentration (r = 0.35, P < 0.0001), and 24-hour urinary iodine excretion (r = 0.40, P < 0.0001). The prevalence of thyroid nodules (TN) and goiter showed an upward trend with SIC quantiles (P for trend < 0.05). Children with SIC <105 μg/L had a higher risk of insufficient iodine status (OR = 4.18; 95% CI, 2.67-6.56) compared with those with higher SIC. Those having SIC >273 μg/L were associated with greater risks of TN (OR = 2.70; 95% CI, 1.38-5.26) and excessive iodine status (OR = 18.56; 95% CI, 5.66-60.91) than those with lower SIC values. Conclusions There is a good correlation between SIC and urinary iodine concentrations. It is of significant reference value for the diagnosis of iodine deficiency with SIC of less than 105 μg/L and for the diagnosis of iodine excess and TN with SIC of more than 273 μg/L. Given the sanitary nature and convenience of saliva iodine collection, SIC is highly recommended as a good biomarker of recent iodine status in school-aged children.

scholarly journals Mild to Moderate Iodine Deficiency and Inadequate Iodine Intake in Lactating Women in the Inland Area of Norway

Nutrients ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 630 ◽  
Author(s):  
Synne Groufh-Jacobsen ◽  
Lise Mette Mosand ◽  
Ingvild Oma ◽  
Kjersti Sletten Bakken ◽  
Beate Stokke Solvik ◽  
...  
Keyword(s):  
Human Milk ◽  
Infant Health ◽  
Urinary Iodine ◽  
Iodine Concentration ◽  
Iodine Intake ◽  
Public Health Care ◽  
Urinary Iodine Concentration ◽  
Cross Sectional ◽  
Lactating Women ◽  
Iodine Status

Breastfed infants are dependent on an adequate supply of iodine in human milk for the production of thyroid hormones, necessary for development of the brain. Despite the importance of iodine for infant health, data on Norwegian lactating women are scarce. We measured iodine intake and evaluated iodine status and iodine knowledge among lactating women. From October to December 2018, 133 mother–infant pairs were recruited in a cross-sectional study through two public health care centers in Lillehammer and Gjøvik. Each of the women provided two human milk specimens, which were pooled, and one urine sample for analysis of iodine concentration. We used 24-h dietary recall and food frequency questionnaire (FFQ) to estimate short-term and habitual iodine intake from food and supplements. The median (P25, P75) human milk iodine concentration (HMIC) was 71 (45, 127) µg/L—of which, 66% had HMIC <100 µg/L. The median (P25, P75) urinary iodine concentration (UIC) was 80 µg/L (52, 141). The mean (± SD) 24-h iodine intake and habitual intake was 78 ± 79 µg/day and 75 ± 73 µg/day, respectively. In conclusion, this study confirms inadequate iodine intake and insufficient iodine status among lactating women in the inland area of Norway and medium knowledge awareness about iodine.

scholarly journals Current trends of 24-h urinary iodine excretion in German schoolchildren and the importance of iodised salt in processed foods

2011 ◽  
Vol 106 (11) ◽  
pp. 1749-1756 ◽  
Author(s):  
Simone A. Johner ◽  
Anke L. B. Günther ◽  
Thomas Remer
Keyword(s):  
Urinary Iodine ◽  
Iodine Concentration ◽  
Urinary Iodine Excretion ◽  
Urinary Iodine Concentration ◽  
Processed Foods ◽  
Food Groups ◽  
Linear Regression Models ◽  
Iodine Status ◽  
Iodised Salt ◽  
Iodine Excretion

Worldwide, the iodisation of salt has clearly improved iodine status. In industrialised countries, iodised salt added to processed food contributes most to iodine supply. Yet it is unclear as to what extent changes in the latter may affect the iodine status of populations. Between 2004 and 2009, 24-h urinary iodine excretions (UIE) were repeatedly measured in 278 German children (6 to 12 years old) of the Dortmund Nutritional and Anthropometric Longitudinally Designed Study (n707). Na excretion measurements and simultaneously collected 3-d weighed dietary records provided data on intakes of the most important dietary sources of iodine in the children's diet. Actual trends of UIE (2004–9) and contributions of relevant food groups were analysed by mixed linear regression models. Longitudinal regression analysis showed a plateau of UIE in 2004–6; afterwards, UIE significantly decreased till 2009 (P = 0·01; median 24-h UIE in 2004–6: 85·6 μg/d; 2009: 80·4 μg/d). Median urinary iodine concentration fell below the WHO criteria for iodine sufficiency of 100 μg/l in 2007–9. Salt, milk, fish and egg intake (g/d) were significant predictors of UIE (P < 0·005); and the main sources of iodine were salt and milk (48 and 38 %, respectively). The present data hint at a beginning deterioration in the iodine status of German schoolchildren. A decreased use of iodised salt in industrially produced foods may be one possible reason for this development. Because of the generally known risks for cognitive impairment due to even mild iodine deficits in children, a more widespread use of iodised salt, especially in industrially processed foods, has to be promoted.

scholarly journals Iodine nutrition in pregnancy and lactation in Iran

2007 ◽  
Vol 10 (12A) ◽  
pp. 1596-1599 ◽  
Author(s):  
Fereidoun Azizi
Keyword(s):  
Pregnant Women ◽  
Urinary Iodine ◽  
Thyroid Volume ◽  
Iodine Concentration ◽  
Iodine Intake ◽  
Urinary Iodine Excretion ◽  
Urinary Iodine Concentration ◽  
Lactating Women ◽  
Iodine Excretion ◽  
Pregnancy And Lactation

AbstractObjective: To describe studies evaluating urinary iodine excretion during pregnancy and lactation in women living in cities with adequate or more than adequate iodine intake.Design: Cross-sectional study conducted between 1996 and 1998 in pregnant women and a study of lactating women conducted in 2003.Settings and Subjects: Pregnant women attending prenatal clinics in four cities in the Islamic Republic of Iran. Urinary iodine excretion and thyroid volume was measured in 403 women. In a second study, 100 lactating women from Taleghani Hospital in Gorgan, Iran were evaluated for thyroid size, and both urinary and breast milk iodine concentrations were determined.Results: In Rasht city, 84% of pregnant women had a urinary iodine concentration of ≥ 200 μg l-1, while in the other cities this percentage ranged from 45 to 55%. When data were combined for the cities of Ilam, Isfahan and Tehran, where women have an adequate or more than adequate median urinary iodine concentration, 51% of pregnant women had a urinary iodine concentration less than that recommended during pregnancy. In Rasht, where the median urinary iodine concentration indicates an excessive iodine intake, 15.4% of pregnant women had a urinary iodine concentration < 200 μg l-1. The mean urinary iodine concentration in lactating women was 250 μg l-1, and 16% of women had a urinary iodine concentration < 100 μg l-1. Grade 1 goitre was present in 8% of lactating women, and another 8% had grade 2 goitre.Conclusions: Findings of this study call for further attention to iodine intake during pregnancy and lactation. The currently recommended intake of iodine through universal salt iodisation may not be adequate for pregnant and lactating women, and supplementation during pregnancy and lactation should be further considered in light of the latest recommendations.

scholarly journals A cross-sectional study on iodine status among pregnant and non-pregnant women of Tripura: a North-Eastern state of India

2019 ◽  
Vol 7 (2) ◽  
pp. 486
Author(s):  
Nilratan Majumder ◽  
Balaram Sutradhar ◽  
Saradindu Riang ◽  
Shib Sekhar Datta
Keyword(s):  
Pregnant Women ◽  
Iodine Deficiency ◽  
Urinary Iodine ◽  
Cross Sectional Study ◽  
Iodine Intake ◽  
Urinary Iodine Excretion ◽  
Metabolic Demand ◽  
Cross Sectional ◽  
Iodine Status ◽  
Iodine Excretion

Background: Due to excess metabolic demand of iodine in pregnancy, pregnant women and lactating mother and their neonates are most vulnerable of iodine deficiency disorder. Urinary iodine excretion is a good marker of recent dietary iodine intake. Thus, present study was conducted to assess the iodine status and median urinary iodine excretion (UIE μg/lit) among pregnant and non-pregnant women of Tripura.Methods: Tribal and Bengali pregnant and non-pregnant women from Bokafa and Jolaibari Block of South Tripura district were included in the study. Urinary iodine excretion was done using simple micro plate method. Salt iodine was estimated using iodometric titration. All the tests were performed at CNRT Lab, ICMR, India.Results: Total number of subjects included in this study was 1071. Total number of urine samples collected from pregnant and non-pregnant women was 538 and 533 respectively. Median value of UIE in pregnant and non-pregnant women of Tripura was 155.0µg/L and 130.0µg/L. In pregnant women percentage prevalence of severe (<20µg/L), moderate (20-49µg/L) and mild iodine deficiency (50-149µg/L) was found in 4.1%, 15.1% and 29.6% subjects. In case of non-pregnant women severe (<20µg/L), moderate (20-49µg/L) and mild iodine deficiency (50-99µg/L) was found in 0.6%, 9.6%, 27.8% subjects respectively. The overall prevalence of iodine deficiency was found in 48.8% pregnant women, compared to 38.0% non-pregnant subjects.Conclusions: Efforts towards universal salt iodization need to be stepped-up in Sub-Himalayan region (NE part of India) and pregnant and lactating mothers may be targeted with alternate iodine supplements (Colloidal Iodine).

scholarly journals Use of Salivary Iodine Concentrations to Estimate the Iodine Status of Adults in Clinical Practice

2021 ◽  
Author(s):  
Bernadette L Dekker ◽  
Daan J Touw ◽  
Anouk N A van der Horst-Schrivers ◽  
Michel J Vos ◽  
Thera P Links ◽  
...  
Keyword(s):  
Inductively Coupled Plasma ◽  
Urinary Iodine ◽  
Iodine Concentration ◽  
Salivary Protein ◽  
Diet Group ◽  
Urinary Iodine Excretion ◽  
Urinary Iodine Concentration ◽  
Total Iodine ◽  
Iodine Status ◽  
Iodine Excretion

ABSTRACT Background Measurement of the 24-h urinary iodine concentration or urinary iodine excretion (UIE) is the gold standard to determine iodine status; however, this method is inconvenient. The use of salivary iodine could be a possible alternative since salivary glands express the sodium-iodine symporter. Objectives We aimed to establish the correlation between the salivary iodine secretion and UIE, to evaluate the clinical applicability of the iodine saliva measurement. Methods We collected 24-h urine and saliva samples from 40 participants ≥18 y: 20 healthy volunteers with no specific diet (group 1), 10 patients with differentiated thyroid cancer with a low dietary intake (&lt;50 μg/d, group 2), and 10 patients with a high iodine status as the result of the use of amiodarone (group 3). Urinary and salivary iodine were measured using a validated inductively coupled plasma MS method. To correct for differences in water content, the salivary iodine concentration (SIC) was corrected for salivary protein and urea concentrations (SI/SP and SI/SU, respectively). The intra- and inter-individual CVs were calculated, and the Kruskal-Wallis test and Spearman's correlation were used. Results The intra-individual CVs for SIC, SI/SP, and SI/SU were 63.8%, 37.7%, and 26.9%, respectively. The inter-individual CVs for SIC, SI/SP, and SI/SU were 77.5%, 41.6% and 47.0%, respectively. We found significant differences (P &lt; 0.01) in urinary and salivary iodine concentrations between all groups [the 24-h UIE values were 176 μg/d (IQR, 96.1–213 μg/d), 26.0 μg/d (IQR, 22.0–37.0 μg/d), and 10.0*103 μg/d (IQR, 7.57*103–11.4*103 μg/d) in groups 1–3, respectively; the SIC values were 136 μg/L (IQR, 86.3–308 μg/L), 71.5 μg/L (IQR, 29.5–94.5 μg/L), and 14.3*103 μg/L (IQR, 10.6*103–25.6*103 μg/L) in groups 1–3, respectively]. Correlations between the 24-h UIE and SIC, SI/SP, and SI/SU values were strong (ρ = 0.80, ρ = 0.90, and ρ = 0.86, respectively; P &lt; 0.01). Conclusions Strong correlations were found between salivary and urinary iodine in adults with different daily iodine intakes. A salivary iodine measurement can be performed to assess the total iodine body pool, with the recommendation to correct for salivary protein or urea.

scholarly journals Urinary Iodine Concentration as an Indicator of Iodine Status and its Correlation with the Thyroid Hormones and Hemoglobin Levels in First Trimester Pregnant Women - An Exploratory Study

2021 ◽  
Vol 9 (3) ◽  
pp. 791-799
Author(s):  
Syeda Farha S ◽  
Asna Urooj
Keyword(s):  
Pregnant Women ◽  
Iron Status ◽  
Urinary Iodine ◽  
Iodine Concentration ◽  
First Trimester ◽  
Iodine Intake ◽  
Urinary Iodine Concentration ◽  
Cross Sectional ◽  
Iodine Status ◽  
The Impact

During pregnancy, the daily requirement of iodine increases making those most at-risk population for iodine deficiency disorders. The available confined data shows that pregnant women are iodine deficient even in iodine sufficient regions with this background the objectives of the current study were to assess the urinary iodine concentration (UIC) and evaluate the relationship between the levels of hemoglobin, UIC, and thyroid status in first-trimester pregnant women. A cross-sectional hospital-based study with a total sample size of n=110 pregnant women at the13th week of gestation in the Mysuru district was selected. The UIC, anthropometric measurements, iodine intake, and selected biochemical parameters (TSH, FT3, FT4, and Hb) were assessed. The data was analysed using SPSS (v 16.0). Spearman’s rank correlation test was used to analyse correlations. The Mann- Whitney U test was used to compare differences between groups. ANOVA was used to study the comparison of pregnancy complications with UIC and hemoglobin. The median UIC (mUIC) was 194.2 µg/L and Hb was 10.5 g/dL. Even though the mUIC was normal, around 38.2% had insufficient UIC. Significant inverse relationship between UIC and TSH (r = -0.487, p<0.001), Hb and TSH (r = -0.355, p < 0.001), and between TSH and iodine intake (r=-0.476, p<0.001) were observed. It was interesting to observe that those with insufficient UIC were found to have mild anaemia and low FT4 levels and those with excess UIC had lower TSH levels. The pregnant women in the present study were found to have the normal median urinary iodine concentration and were mildly anaemic. Increased attention among pregnant women should be focused on iodine status along with iron status and thyroid functions. Larger comparative studies need to be performed to study the impact of altered iodine status on neonatal outcomes.

scholarly journals Using seaweed as a supplement or a food ingredient to increase iodine status in women with low habitual intake

2020 ◽  
Vol 79 (OCE2) ◽  
Author(s):  
Katie Nicol ◽  
Cara Swailes ◽  
Layla Alahmari ◽  
Emilie Combet
Keyword(s):  
Urinary Iodine ◽  
Iodine Concentration ◽  
Iodine Intake ◽  
Urinary Iodine Excretion ◽  
Urinary Iodine Concentration ◽  
Food Groups ◽  
Food Ingredient ◽  
Iodine Status ◽  
Spot Urine ◽  
Excess Iodine

AbstractIntroduction: Most consumers remain unaware of iodine sources in the diet. With no prophylaxis, iodine insufficiency remains a largely unappreciated issue in the UK. Including seaweed to the food supply represents a solution and opportunity but this supply needs to be carefully curated and calibrated, as excess iodine may be harmful for thyroid health. This project aimed to test the efficacy of a proof-of-concept reformulated food using seaweed as an ingredient source of iodine, to supplement women who have a habitual low iodine intake.Materials and Methods: Self-reported healthy women, pre-menopausal who avoid iodine-rich foods were randomised to: P1) reformulated food (pizza)with seaweed ingredient, or P2) a control food, similar to P1 but without supplemental iodine, or S1) control, empty capsules, or S2) PureSea Natural ascophyllum nodosum seaweed capsules, the ingredient used in P1. Capsules or food were to be consumed three times per week (providing 400μg iodine per intake). At least 10 spot urine samples were collected per person over at least 3 days preceding each study point. Urinary iodine was measured with a modified Sandell-Koltoff assay.Results: Participants (n = 96, median age 29, IQR 23–42) had a habitual iodine intake of 64μg/d (IQR 39–119, no detectable difference between groups). Dropout rates at 3-month were 41% (P1 &P2 each), 21% for S1, 11% for S2.Baseline urinary iodine concentration (UIC) was low/marginal, at 66μg/L (IQR 34-71), 64μg/L (IQR 40-96), 54μg/L (IQR 31-86) and 39μg/L (IQR 21-64) for P1, P2, S1 and S2 respectively (no difference between groups, p > 0.05).Change in UIC differed between groups at week-2 (p < 0.001), increasing in P1 & S2: by 45μg/L (IQR 2-69), and 35μg/L (IQR 13-48), respectively, decreasing in S1: -14μg/L (IQR –24-(–1)), with no change in group P2. This remained true for groups S1 & S2 when urinary iodine excretion was corrected for creatinine.After 3 months, differences in changes from baselines remained between groups (p < 0.01), with an increase in groups P1 and S2: 28μg/L (IQR 1-112), 43μg/L (IQR 23-93) but not groups P2 or S1. This remained true when UIC was corrected for creatinine.Changes in weight between and within groups were not detected at either time points, with group median changes within 2 kg of baseline weight.Discussion: Iodine-rich seaweed is effective in increasing the iodine status of women with a low habitual iodine intake, as a supplement, or as an ingredient in a cooked reformulated product. In term of feasibility, large attrition in the food groups P1 and P2 demands further attention, for interpretation of data and future translation of the findings.

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