Prevalence of Iodine Insufficiency Is High Among Pregnant and Lactating Women in Northern Bangladesh Three Decades After Initiating Mandatory Salt Iodization

Abstract Objectives Optimum Iodine status during pregnancy and lactation is crucial for normal fetal growth and child development. We assessed the urinary iodine concentration of pregnant and lactating women to determine their iodine status and measured salt iodine from their households. Methods We collected spot urine samples and corresponding household salt samples from 80 pregnant women (37 and 43 second and third-trimester women, respectively) and 49 lactating women (with children <6 months). Urinary iodine was determined by manual digestion with ammonium persulfate followed by Sandell-Kolthoff Reaction using 96 multi-well plates and a micro-plate reader at 405 nm. The iodine content in salt was measured by iodometric titration method. Samples were analyzed at the icddr, b Immunology, Nutrition, and Toxicology Laboratory, Dhaka, Bangladesh. Results The median [IQR] UIC in the second-trimester women, third-trimester women, and lactating women was 90.6[41.9–171.5] mcg/L, 67.9[24.2–144.5] mcg/L, and 74.7[48.1–134.8] mcg/L, respectively. More than three-quarters of pregnant women (73% of the second-trimester women and 79% of the third-trimester women) and more than half of the lactating mothers (57%) were below the WHO recommended cut-offs. Only 42% of the household salts were adequately iodized. A moderate positive linear relationship was found between urinary and household salt iodine content (r = 0.51, P < 0.0001). Conclusions Even with mandatory salt iodization policy in Bangladesh for about three decades, the iodine insufficiency among pregnant and lactating women is widespread and needs to be improved through ensuring the availability of adequately iodized salt or supplement. Funding Sources ETH Zurich, Switzerland.

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Relationship of household cooking salt and eating out on iodine status of pregnant women in environmental iodine-deficient coastal areas of China

British Journal Of Nutrition ◽

10.1017/s000711452000207x ◽

2020 ◽

Vol 124 (9) ◽

pp. 971-978

Author(s):

Zhengyuan Wang ◽

Wei Jin ◽

Zhenni Zhu ◽

Xueying Cui ◽

Qi Song ◽

...

Keyword(s):

Pregnant Women ◽

Urinary Iodine ◽

Iodine Content ◽

Urinary Iodine Concentration ◽

Third Trimester ◽

Iodine Status ◽

Iodised Salt ◽

Home Cooking ◽

Eating Out ◽

Relationship Of

AbstractAs city residents eat out more frequently, it is unknown that if iodised salt is still required in home cooking. We analysed the relationship of household salt and eating out on urinary iodine concentration (UIC) in pregnant women. A household condiment weighing method was implemented to collect salt data for a week. A household salt sample was collected. A urine sample was taken at the end of the week. Totally, 4640 participants were investigated. The median UIC was 139·1 μg/l in pregnant women and 148·7, 140·0 and 122·9 μg/l in the first, second and third trimesters. Median UIC in the third trimester was lower than in the other trimesters (P < 0·001). The usage rates of iodised (an iodine content ≥ 5·0 mg/kg) and qualified-iodised (an iodine content ≥ 21·0 mg/kg) salt were 73·9 and 59·3 %. The median UIC in the qualified-iodised salt group was higher than in the non-iodised group (P = 0·037). The median UIC in the non-iodised group who did not eat out was lower than in qualified-salt groups who both did and did not eat out (P = 0·007, <0·001). The proportion of qualified-iodised salt used in home cooking is low, but foods eaten out have universal salt iodisation according to the national compulsory policy. Household iodised salt did not play a decisive role in the iodine status of pregnant women. Pregnant women in their third trimester who are not eating out and using non-iodised salt at home require extra iodine.

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IODINE STATUS OF PREGNANT WOMEN RESIDING IN URBAN SLUMS IN DELHI

Asian Journal of Pharmaceutical and Clinical Research ◽

10.22159/ajpcr.2018.v11i7.25002 ◽

2018 ◽

Vol 11 (7) ◽

pp. 506

Author(s):

Spriha Rao ◽

Gurudayal Singh Toteja ◽

Neena Bhatia ◽

Supriya Dwivedi ◽

Zaozianlungliu Gonmei ◽

...

Keyword(s):

Pregnant Women ◽

Urinary Iodine ◽

Urban Slums ◽

Iodized Salt ◽

Nutrition Status ◽

Urinary Iodine Concentration ◽

Iodine Nutrition ◽

Cross Sectional ◽

Iodine Status ◽

Salt Iodine

Objectives: The present study was carried out to determine the iodine nutrition status among pregnant women in slums of West Delhi.Methods: A community-based cross-sectional study was carried out among the third-trimester pregnant women residing in urban slums of West Delhi. Urinary iodine concentration was estimated using ammonium persulfate method, and salt iodine was estimated using iodometric titration.Results: Of the total 180 pregnant women, 70.6% were consuming adequately iodized salt (iodine levels ≥15 ppm). Median urinary iodine level for the pregnant women was 147.5 μg/L indicating iodine deficiency among this group. A total of 51.1% of women had urinary iodine levels <150 μg/L.Conclusion: Pregnant women belonging to slum community from Delhi have a suboptimal iodine status. Further, the proportion of women consuming iodized salt is less than the national average indicating the need to educate these women about the importance of iodine during pregnancy.

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Iodine deficiency among Belgian pregnant women not fully corrected by iodine-containing multivitamins: a national cross-sectional survey

British Journal Of Nutrition ◽

10.1017/s0007114512004473 ◽

2012 ◽

Vol 109 (12) ◽

pp. 2276-2284 ◽

Cited By ~ 32

Author(s):

Stefanie Vandevijvere ◽

Sihame Amsalkhir ◽

Ahmed Bensouda Mourri ◽

Herman Van Oyen ◽

Rodrigo Moreno-Reyes

Keyword(s):

Pregnant Women ◽

Iodine Deficiency ◽

Urinary Iodine ◽

Iodine Intake ◽

Urinary Iodine Concentration ◽

Childbearing Age ◽

Third Trimester ◽

Cross Sectional Survey ◽

Cross Sectional ◽

Iodine Status

Low iodine intake during pregnancy may cause thyroid dysfunction in pregnant women and their newborn. In the present study, iodine status among a nation-wide representative sample of Belgian pregnant women in the first and third trimester of pregnancy was determined, and determinants of iodine status were assessed 1 year after the introduction of bread fortified with iodised salt. The women were selected according to a multistage proportionate-to-size sampling design. Urine samples were collected and a general questionnaire was completed face to face with the study nurse. The median urinary iodine concentration (UIC) among pregnant women (n1311) was 124·1 μg/l and 122·6 μg/g creatinine when corrected for urinary creatinine. The median UIC in the first trimester (118·3 μg/l) was significantly lower than that in the third trimester (131·0 μg/l) but significantly higher than among non-pregnant women (84·8 μg/l). Iodine-containing supplement intake was reported by 60·8 % of the women and 57·4 % of the women took this supplement daily. The risk of iodine deficiency was significantly higher in younger women, in women not taking iodine-containing supplements, with low consumption of milk and dairy drinks and during autumn. Women with a higher BMI had a higher risk of iodine deficiency but the risk was lower in women who reported alcohol consumption. The median UIC during pregnancy indicates iodine deficiency in Belgium and some women are at a higher risk of deficiency. The current low iodine intake in women of childbearing age precludes the correction of iodine deficiency in pregnant women supplemented with multivitamins containing 150 μg iodine as recommended.

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The impact of iodised salt or iodine supplements on iodine status during pregnancy, lactation and infancy

Public Health Nutrition ◽

10.1017/s1368980007360965 ◽

2007 ◽

Vol 10 (12A) ◽

pp. 1584-1595 ◽

Cited By ~ 50

Author(s):

Michael B Zimmermann

Keyword(s):

Pregnant Women ◽

Urinary Iodine ◽

Iodine Concentration ◽

Iodine Intake ◽

Urinary Iodine Concentration ◽

Life Stages ◽

Lactating Women ◽

Iodine Status ◽

Iodised Salt ◽

The Impact

AbstractObjectives:Monitoring of iodine status during pregnancy, lactation and infancy is difficult as there are no established reference criteria for urinary iodine concentration (UI) for these groups; so it is uncertain whether iodized salt programs meet the needs of these life stages.Design and Subjects:The method used in this paper was: 1) to estimate the median UI concentration that reflects adequate iodine intake during these life stages; and 2) to use these estimates in a review of the literature to assess whether salt iodisation can control iodine deficiency in pregnant and lactating women, and their infants.Results:For pregnancy, recommended mean daily iodine intakes of 220-250 μg were estimated to correspond to a median UI concentration of about 150 μg l− 1, and larger surveys from the iodine sufficient countries have reported a median UI in pregnant women ≥ 140 μg l− 1. Iodine supplementation in pregnant women who are mild-to-moderately iodine deficient is beneficial, but there is no clear affect on maternal or newborn thyroid hormone levels. In countries where the iodine intake is sufficient, most mothers have median breast milk iodine concentration (BMIC) greater than the concentration (100-120 μg l− 1) required to meet an infant's needs. The median UI concentration during infancy that indicates optimal iodine nutrition is estimated to be ≥ 100 μg l− 1. In iodine-sufficient countries, the median UI concentration in infants ranges from 90-170 μg l− 1, suggesting adequate iodine intake in infancy.Conclusions:These findings suggest pregnant and lactating women and their infants in countries with successful sustained iodised salt programs have adequate iodine status.

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

Nutrition Journal ◽

10.1186/s12937-021-00676-7 ◽

2021 ◽

Vol 20 (1) ◽

Author(s):

Yixuan Lin ◽

Diqun Chen ◽

Jiani Wu ◽

Zhihui Chen

Keyword(s):

Pregnant Women ◽

Urinary Iodine ◽

Interquartile Range ◽

Iodized Salt ◽

School Age Children ◽

Fujian Province ◽

Cross Sectional ◽

Lactating Women ◽

Iodine Status ◽

Salt Iodization

Abstract 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.

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Urinary iodine concentration identifies pregnant women as iodine deficient yet school-aged children as iodine sufficient in rural Niger

Public Health Nutrition ◽

10.1017/s1368980016003232 ◽

2016 ◽

Vol 20 (7) ◽

pp. 1154-1161 ◽

Cited By ~ 7

Author(s):

Sonja Y Hess ◽

Césaire T Ouédraogo ◽

Rebecca R Young ◽

Ibrahim F Bamba ◽

Sara Stinca ◽

...

Keyword(s):

Pregnant Women ◽

Iodine Deficiency ◽

Venous Blood ◽

Urinary Iodine ◽

Iodine Content ◽

Iodine Concentration ◽

Interquartile Range ◽

Urinary Iodine Concentration ◽

Iodine Status ◽

School Aged Children

AbstractObjectiveTo assess iodine status among pregnant women in rural Zinder, Niger and to compare their status with the iodine status of school-aged children from the same households.DesignSeventy-three villages in the catchment area of sixteen health centres were randomly selected to participate in the cross-sectional survey.SettingSalt iodization is mandatory in Niger, requiring 20–60 ppm iodine at the retail level.SubjectsA spot urine sample was collected from randomly selected pregnant women (n662) and one school-aged child from the same household (n373). Urinary iodine concentration (UIC) was assessed as an indicator of iodine status in both groups. Dried blood spots (DBS) were collected from venous blood samples of pregnant women and thyroglobulin (Tg), thyroid-stimulating hormone and total thyroxine were measured. Iodine content of household salt samples (n108) was assessed by titration.ResultsMedian iodine content of salt samples was 5·5 ppm (range 0–41 ppm), 98 % had an iodine content <20 ppm. Median (interquartile range) UIC of pregnant women and school-aged children was 69·0 (38·1–114·3) and 100·9 (61·2–163·2) µg/l, respectively. Although nearly all pregnant women were euthyroid, their median (interquartile range) DBS-Tg was 34·6 (23·9–49·7) µg/l and 38·4 % had DBS-Tg>40 µg/l.ConclusionsIn this region of Niger, most salt is inadequately iodized. UIC in pregnant women indicated iodine deficiency, whereas UIC of school-aged children indicated marginally adequate iodine status. Thus, estimating population iodine status based solely on monitoring of UIC among school-aged children may underestimate the risk of iodine deficiency in pregnant women.

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Iodine Status of Taiwanese Population in 2013: 10 Years After Changing From Mandatory to Voluntary Salt Iodization

Food and Nutrition Bulletin ◽

10.1177/0379572117738883 ◽

2017 ◽

Vol 39 (1) ◽

pp. 75-85 ◽

Cited By ~ 2

Author(s):

Fan-Fen Wang ◽

Kam-Tsun Tang ◽

Wen-Harn Pan ◽

Justin Ging-Shing Won ◽

Yao-Te Hsieh ◽

...

Keyword(s):

Age Groups ◽

Urinary Iodine ◽

Iodine Concentration ◽

World Health ◽

Urinary Iodine Concentration ◽

Taiwanese Population ◽

Iodine Nutrition ◽

Iodine Status ◽

Salt Iodization ◽

Health Organization

Background: In 2003, Taiwan’s iodine policy changed from mandatory to voluntary. The Nutrition and Health Survey in Taiwan (NAHSIT) 2001-2002 for schoolchildren showed adequate iodine nutrition, while NAHSIT 2005-2008 for adults showed the iodine status was at borderline adequacy. Objective: To investigate the iodine status of the Taiwanese population from schoolchildren to adulthood 10 years after the change of the salt iodization policy. Method: Urinary iodine was measured in samples from subjects in NAHSIT 2013. Results: The median urinary iodine concentration (UIC) of the Taiwanese population aged 6 years and above in 2013 was 96 μg/L, indicating mild iodine deficiency. The median UIC of 6- to 12-year-old schoolchildren was 124 μg/L (interquartile range [IQR]: 92-213 μg/L), and 115 μg/L (IQR: 80-166 μg/L), 125 μg/L (IQR: 74-161 μg/L), 73 μg/L (IQR: 52-131 μg/L), and 78 μg/L (IQR: 52-132 μg/L) in populations aged 13 to 18 years, 19 to 44 years, 45 to 64 years, and ≥65 years, respectively. Declining iodine nutrition in age groups ≥45 years old was noted that the median UIC of populations aged 45 to 64 years and ≥65 years was 99 and 88 μg/L, respectively, in NAHSIT 2005-2008. The median UIC of schoolchildren was not lower than that during the mandatory salt fortification period, but the distribution of urinary iodine levels signified a dietary pattern change. Conclusion: Wide-ranging variation in iodine nutrition levels was observed in different age groups. Universal salt iodization, as suggested by the World Health Organization, should be the best strategy to achieve adequate iodine nutrition.

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Variation of iodine status during pregnancy and its associations with thyroid function in women from Rio de Janeiro, Brazil

Public Health Nutrition ◽

10.1017/s1368980019000399 ◽

2019 ◽

pp. 1-9 ◽

Cited By ~ 2

Author(s):

Carolina Martins Corcino ◽

Tatiana Martins Benvenuto Louro Berbara ◽

Débora Ayres Saraiva ◽

Nathalie Anne de Oliveira e Silva de Morais ◽

Annie Schtscherbyna ◽

...

Keyword(s):

Thyroid Function ◽

Subclinical Hypothyroidism ◽

Rio De Janeiro ◽

Urinary Iodine ◽

Urinary Iodine Concentration ◽

Thyroid Antibodies ◽

Third Trimester ◽

Iodine Status ◽

The Third ◽

Increased Risk

AbstractObjectiveTo assess iodine status and its effects on maternal thyroid function throughout pregnancy.DesignIn the present prospective cohort study, three urinary samples were requested for urinary iodine concentration (UIC) determinations in both the first and third gestational trimesters. Serum thyrotropin (TSH) and free thyroxine (FT4) were analysed in both trimesters and thyroid antibodies were assessed once.SettingRio de Janeiro, Brazil.ParticipantsFirst-trimester pregnant women (n243), of whom 100 were re-evaluated during the third trimester.ResultsIodine sufficiency was found in the studied population (median UIC=216·7 µg/l). The first- and third-trimester median UIC was 221·0 and 208·0 µg/l, respectively. TSH levels (mean (sd)) were higher in the third trimester (1·08 (0·67)v. 1·67 (0·86) mIU/l;P<0·001), while FT4levels decreased significantly (1·18 (0·16)v. 0·88 (0·12) ng/dl;P<0·001), regardless the presence of iodine deficiency (UIC<150 µg/l) or circulating thyroid antibodies. UIC correlated (β; 95% CI) independently and negatively with age (–0·43; –0·71, –0·17) and positively with multiparity (0·15; 0·02, 0·28) and BMI (0·25; 0·00, 0·50). Furthermore, median UIC per pregnant woman tended to correlate positively with TSH (0·07; –0·01, 0·14). Women with median UIC≥250 µg/l and at least one sample ≥500 µg/l throughout pregnancy had a higher risk of subclinical hypothyroidism (OR=6·6; 95% CI 1·2, 37·4).ConclusionsIn this cohort with adequate iodine status during pregnancy, excessive UIC was associated with an increased risk of subclinical hypothyroidism.

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Urinary iodine concentration: a biochemical parameter for assessing the iodine status

Mediscope ◽

10.3329/mediscope.v5i2.37146 ◽

2018 ◽

Vol 5 (2) ◽

pp. 30-35

Author(s):

GM Molla

Keyword(s):

Iodine Deficiency ◽

Urinary Iodine ◽

Iodine Concentration ◽

Iodine Intake ◽

Urinary Iodine Concentration ◽

Lactating Women ◽

Iodine Status ◽

Excessive Iodine ◽

Pregnancy And Lactation ◽

Neonates And Infants

Iodine is a micronutrient, which is essential for the synthesis of thyroid hormones. Thyroid hormones play a major role in the development of different functional components in different stages of life. The relationship between iodine intake level of a population and occurrences of thyroid disorders U-shaped with an increase from both low and high iodine intake. Iodine deficiency disorders (IDDs) are a major health problem worldwide in all age groups, but infants, school children, and pregnant and lactating women are vulnerable. During pregnancy and lactation, the fetus and infants are sensitive to maternal iodine intake. Even mild iodine deficiency may lead to irreversible brain damage during this period. A main cause of IDDs of neonates and infants is maternal iodine deficiency. Universal salt iodization strategy has been initiated by the World Health Organization and United Nation International Children Emergency Fund by the year 1993 for correction and prevention of iodine deficiency. Excessive iodine causes hypothyroidism, iodine-induced hyperthyroidism and autoimmune thyroid diseases. Iodine deficiency and excessive iodine, both cause goiter. There are many indicators for assessing the IDDs, such as measurement of thyroid size by palpation or ultrasonography, serum thyroid stimulating hormone, and thyroglobulin but these are less sensitive, costly and sometimes interpretation is difficult. Urinary iodine concentration (UIC) is a well-accepted, cost-efficient, and easily obtainable indicator of iodine status. Since the majority of iodine absorbed by the body is excreted in the urine, it is considered a sensitive marker of current iodine intake and can reflect recent changes in iodine status. Iodine requirements are greatly increased during pregnancy and lactation, owing to metabolic changes. During intrauterine life, maternal iodine is the only source of iodine for a fetus. UIC determines the iodine status of pregnant and lactating women. Breast milk is the only source of iodine for exclusively breastfed neonates and infants. Breast milk iodine concentration can be determined by UIC. UIC predicts the adverse health consequences of excessive iodine intake such as goiter, hypothyroidism, and hyperthyroidism. This review presents that iodine status in different groups of a population can be determined by UIC which will be helpful in assessing the iodine status in a community, finding out the cause of thyroid disorders, to predict the risk of adverse health effects of iodine deficiency and excessive iodine, and in making plan for iodine supplementation.Mediscope Vol. 5, No. 2: Jul 2018, Page 30-35

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Dried Blood Spot Thyroglobulin as a Biomarker of Iodine Status in Pregnant Women

The Journal of Clinical Endocrinology & Metabolism ◽

10.1210/jc.2016-2829 ◽

2016 ◽

Vol 102 (1) ◽

pp. 23-32 ◽

Cited By ~ 30

Author(s):

Sara Stinca ◽

Maria Andersson ◽

Sandra Weibel ◽

Isabelle Herter-Aeberli ◽

Ralph Fingerhut ◽

...

Keyword(s):

Pregnant Women ◽

Reference Range ◽

Urinary Iodine ◽

Iodine Intake ◽

Dried Blood Spot ◽

Urinary Iodine Concentration ◽

Iodine Nutrition ◽

Cross Sectional ◽

Iodine Status ◽

Blood Spot

Abstract Context: Thyroglobulin (Tg) could be a sensitive biomarker of iodine nutrition in pregnant women (PW). A dried blood spot (DBS) assay would simplify collection and transport in field studies. Objectives: Our aims were to (1) establish and test a reference range for DBS-Tg in PW; (2) determine whether co-measurement of Tg antibodies (Abs) is necessary to define population iodine status. Design, Setting, and Participants: Standardized cross-sectional studies of 3870 PW from 11 countries. For the DBS-Tg reference range, we included TgAb-negative PW (n = 599) from 3 countries with sufficient iodine intake. Main Outcome Measures: We measured the urinary iodine concentration and DBS thyroid-stimulating hormone, total thyroxin, Tg, and TgAb. Results: In the reference population, the median DBS-Tg was 9.2 μg/L (95% confidence interval, 8.7 to 9.8 μg/L) and was not significantly different among trimesters. The reference range was 0.3 to 43.5 μg/L. Over a range of iodine intake, the Tg concentrations were U-shaped. Within countries, the median DBS-Tg and the presence of elevated DBS-Tg did not differ significantly between all PW and PW who were TgAb-negative. Conclusions: A median DBS-Tg of ∼10 μg/L with <3% of values ≥44 μg/L indicated population iodine sufficiency. Concurrent measurement of TgAb did not appear necessary to assess the population iodine status.

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