scholarly journals Nationwide Representative Survey of Dietary Iodine Intake and Urinary Excretion in Postpartum Korean Women

Nutrients ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 3955
Author(s):  
Do-Kyung Lee ◽  
Hunjoo Lee ◽  
Hyeyoung Lee ◽  
Taehyung Yoon ◽  
Seon-Joo Park ◽  
...  
Keyword(s):  
Large Scale ◽  
Urinary Iodine ◽  
Brown Seaweed ◽  
Nationwide Survey ◽  
Iodine Intake ◽  
Urinary Iodine Excretion ◽  
Korean Women ◽  
Spot Urine ◽  
Before And After ◽  
Iodine Excretion

Iodine is an essential component of thyroid hormones, but excessive iodine intake can lead to thyroid dysfunction. Traditionally, Korean mothers consume brown seaweed soup (miyeokguk), a high source of iodine, after childbirth. There is controversy regarding the effects of excessive postpartum iodine intake on the health of mothers and infants. Thus far, there have been no nationwide large-scale surveys regarding the status of iodine intake among postpartum women in Korea. Therefore, we conducted a nationwide survey of postpartum dietary iodine intake among Korean women. In total, 1054 Korean women aged ≥19 years, at less than 8 weeks postpartum, participated in this survey. Dietary data were collected using self-reported 2-day dietary records, along with before-and-after meal photos. To evaluate the correlation between dietary iodine and urinary iodine excretion (UIE), spot urine, and 24 h urine samples were collected from 98 and 29 participants, respectively. The mean daily iodine intake among all participants was 2945.6 μg, and it gradually decreased over time after childbirth. Dietary iodine intake was significantly correlated with 24 h UIE (r = 0.396, p < 0.05) and spot urine UIE (r = 0.312, p < 0.05). Follow-up studies are required to examine the influence of excessive postpartum iodine intake on thyroid health in mothers and their infants.

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 Reliability of studies of iodine intake and recommendations for number of samples in groups and in individuals

2007 ◽  
Vol 99 (4) ◽  
pp. 813-818 ◽  
Author(s):  
Stig Andersen ◽  
Jesper Karmisholt ◽  
Klaus M. Pedersen ◽  
Peter Laurberg
Keyword(s):  
Standard Deviation ◽  
Urinary Iodine ◽  
Iodine Intake ◽  
Urine Samples ◽  
Urinary Iodine Excretion ◽  
Iodine Nutrition ◽  
Cross Sectional ◽  
Spot Urine ◽  
Iodine Excretion ◽  
And Gender

The iodine intake level in a population is determined in cross-sectional studies. Urinary iodine varies considerably and the reliability of studies of iodine nutrition and the number of samples needed is unsettled. We performed a longitudinal study of sixteen healthy men living in an area of mild to moderate iodine deficiency. Iodine and creatinine concentrations were measured in spot urine samples collected monthly for 13 months. From these data we calculated the number of urine samples needed to determine the iodine excretion level for crude urinary iodine and for 24 h iodine excretion estimated from age- and gender-specific creatinine excretions. We found that mean urinary iodine excretion varied from 30 to 87 μg/l (31 to 91 μg/24 h). Sample iodine varied from 10 to 260 μg/l (20 to 161 μg/24 h). Crude urinary iodine varied more than estimated 24 h iodine excretion (population standard deviation 32v. 26; individual standard deviation 29v. 21; Bartlett's test,P < 0·01 for both). The number of spot urine samples needed to estimate the iodine level in a population with 95 % confidence within a precision range of ± 10 % was about 125 (100 when using estimated 24 h iodine excretions), and within a precision range of ± 5 % was about 500 (400). A precision range of ± 20 % in an individual required twelve urine samples or more (seven when using estimated 24 h iodine excretions). In conclusion, estimating population iodine excretion requires 100–500 spot urine samples for each group or subgroup. Less than ten urine samples in an individual may be misleading.

scholarly journals Iodine intake before and after mandatory iodization in Denmark: results from the Danish Investigation of Iodine Intake and Thyroid Diseases (DanThyr) study

2008 ◽  
Vol 100 (1) ◽  
pp. 166-173 ◽  
Author(s):  
Lone B. Rasmussen ◽  
Allan Carlé ◽  
Torben Jørgensen ◽  
Nils Knudsen ◽  
Peter Laurberg ◽  
...  
Keyword(s):  
Iodine Deficiency ◽  
Age Groups ◽  
Urinary Iodine ◽  
Iodine Concentration ◽  
Iodine Intake ◽  
Urinary Iodine Excretion ◽  
Urinary Iodine Concentration ◽  
Before And After ◽  
Iodine Excretion ◽  
Study Population

Iodine deficiency is still common in some European countries. In Denmark an iodine fortification programme was introduced in 1998 and a monitoring programme was established prior to iodization. This study reports the change in urinary iodine excretion caused by fortification and investigates determinants of iodine intake after fortification. Iodine excretion in casual urine samples was assessed in 4649 subjects in 1997–8 and in 3570 comparable subjects in 2004–5 in women 18–22, 25–30, 40–45 and 60–65 years of age and in men 60–65 years of age living in Aalborg (western part of Denmark) or Copenhagen (eastern part of Denmark). These areas had moderate and mild iodine deficiency, respectively, before iodine fortification. All subjects filled in a FFQ and a questionnaire regarding lifestyle factors. Iodine excretion, expressed as the estimated 24 h urinary iodine excretion and as urinary iodine concentration, increased significantly in all age and sex groups. However, the iodine intake was still below the recommended in the youngest age groups in both cities and in women 40–45 years of age living in Aalborg. Intake of milk and salt had strong significant direct associations with iodine excretion (P < 0·001). It is concluded that although the median iodine intake in the whole study population is at the recommended level, some groups still have an intake below the recommended. It is important to have a moderate milk intake to obtain a sufficient iodine intake in Denmark.

Nativer 99mTc-Uptake in der Differentialdiagnostik von unauffälliger Schilddrüse, Struma mit Euthyreose und Schilddrüsenautonomie in einem Jodmangelgebiet

1990 ◽  
Vol 29 (03) ◽  
pp. 113-119
Author(s):  
C. R. Pickardt ◽  
K. Horn ◽  
G. Bechtner ◽  
C. Vaitl ◽  
C. M. Kirsch ◽  
...  
Keyword(s):  
Urinary Iodine ◽  
Inverse Correlation ◽  
Iodine Concentration ◽  
Urinary Iodine Excretion ◽  
Large Scatter ◽  
Spot Urine ◽  
Iodine Supply ◽  
Iodine Contamination ◽  
Iodine Excretion ◽  
Overt Hyperthyroidism

Global TcTU was determined in 568 patients without any specific thyroid drug intake - 54 with normal thyroid, 274 with goitre and euthyroidism and 240 with thyroid autonomy. 57 patients with autonomy and overt hyperthyroidism were the only group with TcTU values significantly higher than normals. Common to all groups was a large scatter of the TcTU values. In 332, the effects of individual iodine supply were studied by measuring the iodine concentration in spot urine samples. There was a significant inverse correlation between the TcTU values and the urinary iodine excretion in the groups of normal thyroids and of goitres with euthyroidism. In the group with autonomy an effect of iodine supply could only be seen in cases of greatly increased urinary iodine excretion, resulting in very low TcTU values. Out of 20 patients with autonomy and iodine contamination, only 4 showed overt hyperthyroidism. The large scatter of TcTU values in all groups may be explained by the persistent iodine deficiency as well as by the frequent exposure to unknown amounts of iodine in patients with thyroid disease. Therefore, the spontaneous TcTU alone cannot identify a small group of patients with autonomy and high risk of iodine-induced hyperthyroidism, from a very large group of patients with goitre.

Iodine and Goiter in Children

PEDIATRICS ◽  
1975 ◽  
Vol 56 (1) ◽  
pp. 82-90
Author(s):  
Frederick L. Trowbridge ◽  
Josip Matovinovic ◽  
Gordon D. McLaren ◽  
Milton Z. Nichaman
Keyword(s):  
United States ◽  
Urinary Iodine ◽  
The United States ◽  
Iodine Intake ◽  
Urinary Iodine Excretion ◽  
High Iodine ◽  
Goiter Prevalence ◽  
Iodine Excretion ◽  
American Children

Goiter examination was performed on 7,785 children aged 9 to 16 years in four areas of the United States—Michigan, Kentucky, Texas, and Georgia. Urinary iodine and creatinine, thyroxine, protein-bound iodine, and plasma inorganic iodide determinations were made on 377 matched pairs of goitrous and nongoitrous control children. The overall prevalence of goiter was 6.8%. Most children with goiter had palpably but not visibly enlarged thyroids and showed no evidence of clinical or biochemical thyroid abnormality. Mean urinary iodine excretion was 452µg/gm of creatinine, many times the 50µg/gm of creatinine level used to define deficiency. Children with goiter and areas with high goiter prevalence tended to have higher rather than lower iodine excretion. These findings are consistent with other data indicating high iodine intakes in the United States and suggest that goiter in American children cannot be assumed to be related to iodine deficiency. The possible role of high iodine intake in the causation of goiter is discussed.

scholarly journals Chronic iodine excess does not increase the incidence of hyperthyroidism: a prospective community-based epidemiological survey in China

2007 ◽  
Vol 156 (4) ◽  
pp. 403-408 ◽  
Author(s):  
Fan Yang ◽  
Zhongyan Shan ◽  
Xiaochun Teng ◽  
Yushu Li ◽  
Haixia Guan ◽  
...  
Keyword(s):  
Urinary Iodine ◽  
Iodine Intake ◽  
Urinary Iodine Excretion ◽  
Thyroid Peroxidase ◽  
Community Based ◽  
Iodine Excess ◽  
Iodine Supplementation ◽  
Excessive Iodine ◽  
Iodine Excretion ◽  
Excessive Iodine Intake

Objective: An increasing incidence of hyperthyroidism has been observed when iodine supplementation has been introduced to an iodine-deficient population. Moreover, the influence of chronic more than adequate or excessive iodine intake on the epidemiological features of hyperthyroidism has not been widely and thoroughly described. To investigate the influences of different iodine intake levels on the incidence of hyperthyroidism, we conducted a prospective community-based survey in three communities with mild-deficient, more than adequate (previously mild deficient iodine intake), and excessive iodine intake. Subjects and methods: In three rural Chinese communities, a total of 3761 unselected inhabitants aged above 13 years participated in the original investigation and 3018 of them received identical examinations after 5 years. Thyroid function, levels of thyroid peroxidase antibody (TPOAb), thyroglobulin antibody and urinary iodine excretion were measured and thyroid ultrasound examination was also performed. Results: In three communities, median urinary iodine excretion was 88, 214, and 634 μg/l (P<0.05) respectively. The cumulative incidence of hyperthyroidism was 1.4, 0.9, and 0.8% (P>0.05) respectively. Autoimmune hyperthyroidism was predominant in thyroid hyperfunction in all the three cohorts. Either positive TPOAb (>50 U/ml) or goiter in original healthy participants was associated with the occurrence of unsuspected hyperthyroidism in 5 years (logistic regression, OR=4.2 (95% CI 1.7–8.8) for positive TPOAb, OR=3.1 (95% CI 1.4–6.8) for goiter). Conclusion: Iodine supplementation may not induce an increase in hyperthyroidism in a previously mildly iodine-deficient population. Chronic iodine excess does not apparently increase the risk of autoimmune hyperthyroidism, suggesting that excessive iodine intake may not be an environmental factor involved in the occurrence of autoimmune hyperthyroidism.

scholarly journals Iodine bioavailability from cow milk: a randomized, crossover balance study in healthy iodine-replete adults

2019 ◽  
Vol 110 (1) ◽  
pp. 102-110 ◽  
Author(s):  
Olivia L van der Reijden ◽  
Valeria Galetti ◽  
Sarah Bürki ◽  
Christophe Zeder ◽  
Adam Krzystek ◽  
...  
Keyword(s):  
Urinary Iodine ◽  
Iodine Intake ◽  
Cow Milk ◽  
Urinary Iodine Excretion ◽  
High Concentration ◽  
Total Iodine ◽  
Balance Study ◽  
Iodine Absorption ◽  
Iodine Excretion ◽  
Potential Matrix

ABSTRACTBackgroundMilk and dairy products are considered important dietary sources of iodine in many countries. However, to our knowledge, iodine bioavailability from milk has not been directly measured in humans.ObjectiveThe aim of this study was to compare iodine bioavailability in iodine-replete adults from: 1) cow milk containing a high concentration of native iodine; 2) milk containing a low concentration of native iodine, with the addition of potassium iodide (KI) to assess a potential matrix effect; and 3) an aqueous solution of KI as a comparator; with all 3 containing equal amounts of total iodine (263 µg/250 mL). We also speciated iodine in milk.DesignWe conducted a 3-wk, randomized, crossover balance study in adults (n = 12) consuming directly analyzed, standardized diets. During the 3 test conditions — high intrinsic iodine milk (IIM), extrinsically added iodine in milk (EIM), and aqueous iodine solution (AIS) — subjects collected 24-h urine over 3 d and consumed the test drink on the second day, with 3- or 4-d wash-out periods prior to each treatment. Iodine absorption was calculated as the ratio of urinary iodine excretion (UIE) to total iodine intake. Milk iodine speciation was performed using ion chromatography-mass spectrometry.ResultsIodine intake from the standardized diet was 195 ± 6 µg/d for males and 107 ± 6 µg/d for females; the test drinks provided an additional 263 µg. Eleven subjects completed the protocol. There was a linear relation between iodine intake and UIE (β = 0.89, SE = 0.04, P < 0.001). There were no significant differences in UIE among the 3 conditions (P = 0.24). Median (range) fractional iodine absorption across the 3 conditions was 91 (51–145), 72 (48–95), and 98 (51–143)% on days 1, 2, and 3, respectively, with day 2 significantly lower compared with days 1 and 3 (P < 0.001). In milk, 80–93% of the total iodine was inorganic iodide.ConclusionNearly all of the iodine in cow milk is iodide and although fractional iodine absorption from milk decreases with increasing dose, its bioavailability is high. The trial was registered at clinicaltrials.gov as NCT03590431.

Urinary iodine excretion in Belarus children

1995 ◽  
Vol 133 (2) ◽  
pp. 216-217 ◽  
Author(s):  
TA Mityukova ◽  
LN Astakhova ◽  
LD Asenchyk ◽  
MM Orlov ◽  
L VanMiddlesworth
Keyword(s):  
Thyroid Cancer ◽  
Iodine Deficiency ◽  
Urinary Iodine ◽  
Iodine Intake ◽  
Urine Samples ◽  
Urinary Iodine Excretion ◽  
University Of Tennessee ◽  
Iodine Excretion

Mityukova TA, Astakhova LN, Asenchyk LD, Orlov MM, VanMiddlesworth L. Urinary iodine excretion in Belarus children. Eur J Endocrinol 1995;133:216–7. ISSN 0804–4643. Casual urine samples were collected to determine iodine excretion of 1680 Belarus children during 1990–1994. The subjects, 8–16 years old, were from nine different regions of Belarus; 60% were from the Gomel oblast, which has been associated with relatively high levels of radioiodine fallout and increased incidence of thyroid cancer. Most of the median values indicate borderline/low iodine intake or mild iodine deficiency. Ranges were wide but 163 children excreted < 20 μgI/l urine and they should be considered severely deficient in iodine. L VanMiddlesworth, Dept. of Physiology and Biophysics, University of Tennessee, 894 Union Avenue, Memphis, TN 38163, USA

Urinary iodine excretion and individual iodine supplementation among elderly subjects: A cross-sectional investigation in the commune of Randers, Denmark

1995 ◽  
Vol 132 (2) ◽  
pp. 171-174 ◽  
Author(s):  
Klaus M Pedersen ◽  
Eigil Iversen ◽  
Peter Laurberg
Keyword(s):  
Urinary Iodine ◽  
Cross Sectional Study ◽  
Iodine Intake ◽  
Elderly Subjects ◽  
Urinary Iodine Excretion ◽  
Sectional Study ◽  
Cross Sectional ◽  
Iodine Supplementation ◽  
Median Level ◽  
Iodine Excretion

Pedersen KM, Iversen E, Laurberg P. Urinary iodine excretion and individual iodine supplementation among elderly subjects. A cross-sectional investigation in the commune of Randers, Denmark. Eur J Endocrinol 1995;132:171–4. ISSN 0804–4643 Several studies have demonstrated that the iodine intake is relatively low in Denmark. However, the results are difficult to interpret because no information has been given on the frequency of individual iodine supplementation. We performed a cross-sectional study of elderly subjects living in the commune of Randers, Denmark. Urinary iodine excretion was measured in the 423 participants (185 males, 238 females) and a careful history was taken on any possible intake of supplementary iodine. The median urinary iodine excretion was 48.3 μg/g creatinine for the whole population (40.8 μg/g creatinine in males, 53.2 μg/g creatinine in females). In the part of the population that did not take iodine supplementation (46.7%) the median value was 36.1 μg/g creatinine (males 33.8; females 38.8). Regular iodine supplementation taken as an iodine-containing vitamin/mineral tablet was found in 30.8% of the population. This increased the urinary iodine excretion to a median level of 80.5 μg/g creatinine (males 62.0; females 88.0). The study shows that the basic iodine intake level is overestimated if individual iodine supplementation is not taken into account. Such supplementation may lead to median iodine excretion values that seem reasonable, even if the iodine intake of the part of the population not taking iodine (in this study, nearly half of the population) is low. Klaus Pedersen, Department of Internal Medicine and Endocrinology, Aalborg Hospital, Reberbansgade, DK-9000 Aalborg, Denmark

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