Total Iodine Intake Research Articles

Total Iodine Intake From Foods and Dietary Supplements by the U.S Population, NHANES 2011- 2018

Total Iodine Intake From Foods and Dietary Supplements by the U.S Population, NHANES 2011- 2018

Total Iodine Intake From Foods and Beverages, and Top Food Sources for the U.S Population, NHANES 2011- 2018

Total Iodine Intake From Foods and Beverages, and Top Food Sources for the U.S Population, NHANES 2011- 2018

Iodine Metabolism in Urine and Breast Milk among Lactating Women with Adequate Iodine

BackgroundIn lactating women, iodine metabolism is regulated and maintained by the kidneys and mammary glands. Limited research exists on how iodine absorbed by lactating women is distributed between the kidneys and breasts. ObjectivesThis study aimed to accurately evaluate the total iodine intake (TII), urinary iodine excretion (UIE), and breast milk iodine excretion (BMIE) in lactating women and explore the relationship between TII and total iodine excretion (TIE). MethodsA 7-d iodine metabolism study was conducted on 41 lactating women with a mean age of 30 y in Yuncheng and Gaoqing, China, from December 2021 to August 2023. TII and TIE were calculated by measuring the iodine content in food, water, 24-h urine, feces, and breast milk. The urinary iodine excretion rate (UIER), breast milk iodine excretion rate (BMIER), and partitioning of iodine excretion between urine and breast milk were determined. ResultsIodine metabolism studies were performed for 285 d. The median TII and TIE values were 255 and 263 μg/d, respectively. With an increase in TII, UIER, and BMIER, the UIE and BMIE to TII ratio exhibited a downward trend. The median UIER, BMIER, and proportion of iodine excreted in urine and breast milk were 51.5%, 38.5%, 52%, and 37%, respectively. When the TII was <120 μg/d, the BMIER decreased with the increase of the TII (β: −0.90; 95% confidence interval: −1.08, −0.72). ConclusionsWhen maternal iodine intake is low, the proportion in breast milk increases, ensuring sufficient iodine nutrition for infants. In addition, the UIE of lactating women with adequate iodine concentrations is higher than their BMIE.This study was registered at clinicaltrials.gov as NCT04492657.

Exploring Salivary Iodine Concentration as a Biomarker for Iodine Status and Thyroid Nodules in Females From Different Water Iodine Areas: a Cross-sectional Study

BackgroundIt is unclear whether salivary iodine concentration (SIC) can assess iodine status in females from different water iodine regions. ObjectivesThrough a cross-sectional study, we explored the feasibility of SIC as a biomarker to assess iodine status in females and develop optimal cutoff values. MethodsA total of 1991 females were analyzed in this cross-sectional study from the coastal iodine-deficient areas (CIDAs), inland iodine-deficient areas (IIDAs), iodine-adequate areas (IAAs), iodine-excess areas (IEAs), and iodine extra-high areas (IEHAs). SIC, spot urine iodine concentration (SUIC), and daily total iodine intake (TII) were assessed, and ultrasonography was performed in all subjects. ResultsThere was a positive correlation between SIC and SUIC (r = 0.67; 95% CI: 0.64, 0.69; P < 0.001), and TII (r = 0.47; 95% CI: 0.43, 0.50; P < 0.001). The prevalence of thyroid nodules (TN) showed an upward trend with SIC increasing (Z = −2.83; P-trend = 0.005). The area under the receiver-operating characteristic (ROC) curve for SIC to assess iodine deficiency was 0.62 (95% CI: 0.60, 0.65; P < 0.001) and 0.75 (95% CI: 0.73, 0.77; P < 0.001) for iodine excess. The cutoff values were as follows: SIC < 93.32 μg/L, iodine deficiency; 93.32–224.60 μg/L, iodine adequacy; and >224.60 μg/L, iodine excess. When SIC > 224.60 μg/L, the odds ratio (OR) for UIC > 300 μg/L, excessive TII, and the prevalence of TN were 6.44, 3.68, and 1.27 (95% CI: 4.98, 8.31; 2.83, 4.79; and 1.02, 1.56, respectively; P < 0.05); when SIC < 93.32 μg/L, the OR for UIC < 100 μg/L and insufficient TII were 2.34 and 1.94 (95% CI: 1.73, 3.14 and 1.33, 2.83, respectively; P < 0.05). ConclusionsUsing SIC as a biomarker, females in CIDA exhibited mild iodine deficiency, those in IIDA and IAA demonstrated moderate iodine deficiency, and those in IEA and IEHA exhibited an excess of iodine, consistent with SUIC to assess iodine status. SIC can be used as a good biomarker to evaluate the iodine status in population.

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

BackgroundThe 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. ObjectiveThis 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. MethodData 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. ResultsIn 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. ConclusionsThis 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.

An iodine balance study in Chinese school-age children.

Few iodine balance studies have been conducted in school-age children. This study aimed to conduct an iodine balance study in school-aged children. We measured daily iodine intake, excretion, and retention for three consecutive days without any dietary interventions in school-age children. Linear mixed-effects models were used to fit the relationship between total iodine intake (TII) and iodine retention (IR). 29 children aged 7-12 years (mean age 10.2 ± 1.4 years) with normal thyroid function and thyroid volume (Tvol) were recruited. The zero balance value (iodine intake = iodine excretion, iodine retention = 0 μg/d) shifted with iodine intake in an iodine sufficient population. The zero balance value for school-aged children with an iodine intake of 235 (133, 401) μg/d is 164 μg/d. Children aged 7-12 years with iodine intake >400 μg/d were almost in a positive iodine state. An iodine intake of 235 (133, 401) μg/d for children aged 7-10 years achieved a zero balance value of 164 μg/d. Long-term iodine intake of >400 μg/d is not recommended.

Inadequate Iodine Intake in Mothers of Young Children in Innlandet County, Norway

BackgroundIodine has an essential role in child growth and brain development. Thus, sufficient iodine intake is particularly important in women of childbearing age and lactating women. ObjectivesThis cross-sectional study aimed to describe iodine intake in a large random sample of mothers of young children (aged ≤2 y) living in Innlandet County, Norway. MethodsFrom November 2020 to October 2021, 355 mother–child pairs were recruited from public health care centers. Dietary data were obtained using two 24-h dietary recalls (24-HRs) per woman and an electronic FFQ. The Multiple Source Method was used to estimate the usual iodine intake from the 24-HR assessment. ResultsBased on the 24-HRs, the median (P25, P75) usual iodine intake from food was 117 μg/d (88, 153) in nonlactating women and 129 μg/d (95, 176) in lactating women. The median (P25, P75) total usual iodine intake (from food combined with supplements) was 141 μg/d (97, 185) in nonlactating women and 153 μg/d (107, 227) in lactating women. Based on the 24-HRs, 62% of the women had a total iodine intake below the recommendations (150 μg/d in nonlactating women and 200 μg/d in lactating women), and 23% of them had an iodine intake below the average requirement (100 μg/d). The reported use of iodine-containing supplements was 21.4% in nonlactating women and 28.9% in lactating women. In regular users of iodine-containing supplements (n = 63), supplements contributed to an average of 172 μg/d of iodine. Among regular iodine supplement users, 81% reached the recommendations compared with 26% of nonsupplement users (n = 237). The iodine intake estimated by FFQ was substantially higher than that estimated by 24-HRs. ConclusionsMaternal iodine intake in Innlandet County was inadequate. This study confirms the need for action to improve iodine intake in Norway, particularly among women of childbearing age.

Re-exploring the requirement of dietary iodine intake in Chinese female adults based on ‘iodine overflow theory’

PurposeWe re-explored the basal iodine requirement based on healthy Chinese female and a new iodine overflow theory was proposed for iodine balance study.MethodsThirty-six Chinese healthy female adults (age 20.7 ± 1.1) were recruited for this study, which included 40 days low iodine depletion period and six stages of 30 days supplementation period. Uniform diets with low iodine were provided and the content of iodine in the diet was regulated by dairy products. The total iodine intake from food and the total iodine excretion through 24-h urine and staged feces were completely gathered and monitored. The incremental (Δ) intake and excretion over the range were calculated.ResultsThe iodine intake and excretion were 13.6 μg/day and 48.6 μg/day at the first stage, respectively. The incremental iodine intakes and excretions were 21.1 μg/day to 120.3 μg/day and 25.8 μg/day to 105.4 μg/day for the supplementation stages, respectively. According to the ‘iodine overflow theory’, the zero iodine balance (Δ iodine intake = Δ iodine excretion) derived from a mixed effect model indicated a mean iodine intake of 52.2 μg/d (1.0 μg/d kg). The RNI for iodine to healthy Chinese female adult was 73.1 μg/d (1.4 μg/d kg).ConclusionA daily iodine intake of 52.2 μg/d may meet the basal iodine requirement for healthy Chinese female adults, and Chinese female may need more than 20% iodine intake than male based on the ‘iodine overflow theory’. The trial was registered at the Chinese Clinical Trial Registry in May 2018 (No: ChiCTR1800016184).

Iodine Intakes of 550 μg/day are Not Recommended during Pregnancy: A Balance Study

BackgroundAdequate iodine intake during pregnancy is critical for maintaining maternal and fetal thyroid function and development. There are only limited data from iodine-balance studies to inform iodine requirements during pregnancy. ObjectivesThis is an iodine-balance study conducted to explore the associations among iodine intake, excretion, and retention to provide information regarding iodine requirements during pregnancy. MethodsA 7-d iodine-balance experiment enrolled 93 healthy pregnant Chinese women from Hebei, Tanjin, and Shandong. Duplicates of all foods and beverages consumed were systematically collected and measured for iodine content. Iodine excretion was measured by collecting 24-h urine and feces samples. Simple linear regression models were used to assess relationships between total iodine intake and iodine retention, whereas mixed effect models were used to assess the relationship between daily iodine intake and iodine retention. ResultsThe mean ± SD age of participating pregnant women was 29 ± 2 y at a median 22 (IQR: 13–30) wk of gestation. The mean 7-d iodine retention was 43.0 ± 1060 μg/7 d. A negative iodine balance was present in 56% of women whereas 44% had a positive balance. Pregnant women with iodine intakes <150 μg/d were in negative balance whereas those with intakes >550 μg/d were in positive balance. The daily iodine intake at zero balance was 343 μg/d, which was higher in women from Shandong (492 μg/d) than in those from Hebei and Tianjin (202 μg/d). ConclusionsIodine intake at zero balance determined in pregnant women with adequate iodine nutrition is 202 μg/d, and the calculated recommended nutrient intake (RNI) is 280 μg/d. Iodine intakes of <150 μg/d and >550 μg/d are not recommended during pregnancy.This trial was registered at clinicaltrials.gov as NCT03710148.

Comparing feasibility of different tube voltages and different concentrations of contrast medium in coronary CT angiography of overweight patients.

To compare image quality, radiation dose, and iodine intake of coronary computed tomography angiography (CCTA) acquired by wide-detector using different tube voltages and different concentrations of contrast medium (CM) for overweight patients. A total of 150 overweight patients (body mass index≥25 kg/m2) who underwent CCTA are enrolled and divided into three groups according to scan protocols namely, group A (120 kVp, 370 mgI/ml CM); group B (100 kVp, 350 mgI/ml CM); and group C (80 kVp, 320 mgI/ml CM). The CT values, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and figure-of-merit (FOM) of all images are calculated. Images are subjectively assessed using a 5-point scale. In addition, the CT dose index volume (CTDIvol) and dose length product (DLP) of each patient are recorded. The effective radiation dose (ED) is also calculated. Above data are then statistically analyzed. The mean CT values, SNR, CNR, and subjective image quality of group A are significantly lower than those of groups B and C (P < 0.001), but there is no significant difference between groups B and C (P > 0.05). FOMs show a significantly increase trend from group A to C (P < 0.001). The ED values and total iodine intake in groups B and C are 30.34% and 68.53% and 10.22% and 16.85% lower than those in group A, respectively (P < 0.001). The lower tube voltage and lower concentration of CM based on wide-detector allows for significant reduction in iodine load and radiation dose in CCTA for overweight patients comparing to routine scan protocols. It also enhances signal intensity of CCTA and maintains image quality.

Characteristics and predictors of breast milk iodine in exclusively breastfed infants: Results from a repeated-measures study of iodine metabolism.

The iodine supply of exclusively breastfed infants entirely depends upon breast milk. Changes in breast milk iodine affect infants' iodine nutritional status. This study aimed to comprehensively assess the characteristics and predictors of breast milk iodine concentration (BMIC). This 7-day iodine metabolism experiment was conducted in 25 exclusively breastfed mother-infant pairs. The duplicate portion method was used to measure the mother's daily iodine intake from foods and water, and maternal 24-h urine excretion was assessed. We recorded the number of breastfeeds per mother per day and collected breast milk samples before and after each feeding. The median [quartile (Q)1-Q3 range] of BMIC was 115 (86.7, 172) μg/L. The BMIC before breastfeeding was generally higher than that after breastfeeding. Time-sequential analysis found that morning BMIC was most highly correlated with the prior day's iodine intake. Breast milk samples taken in the afternoon or after midnight are closer to the median level of BMIC throughout the day. The number of breast milk samples needed to estimate the iodine level with 95% CI within precision ranges of ± 20% was 83 for a population, 9 for an individual, and 2 for an individual's single day. Maternal total iodine intake (TII) and urine iodine were significantly associated with BMIC. 24-h urinary iodine excretion (24-h UIE) was found to be the best predictive indicator for the BMIC (β = 0.71, 95% CI: 0.64, 0.79). BMIC is a constantly changing indicator and trended downward during each breastfeeding. Breast milk samples taken in the afternoon or after midnight are most representative. BMIC was significantly associated with recent iodine intake. Maternal 24-h UIE was the best predictor of BMIC.

How to Decide the Iodine Content in Salt for a Country-China as an Example.

Globally, many countries have implemented universal salt iodization to prevent and control iodine deficiency disorders. Therefore, it is important to determine the optimal iodine content in salt and to adjust it in a timely manner. This article aims to establish a process for selecting, deciding, and evaluating the iodine content in salt for China and, if possible, providing references for other countries. Information on salt intake, water iodine, and iodine stability in salt was collected. A field investigation was carried out in different populations in four provinces. Iodine intake was calculated and the appropriate iodine content for salt preliminarily obtained, then verified for suitability with 2020 China National Iodine Deficiency Disorders Surveillance data. In total, 2837 children, 1660 adults, and 2145 pregnant women were enrolled, and their iodine intake from food was 3.7-96.1, 60.0-156.0 and 65.0-112.0 µg/d, respectively. After calculation, when the iodine content in salt was 20, 25 and 30 mg/kg, for children and adults, the total iodine intake ranged from 173.4 to 253.5 µg/d and 230.3 to 379.8 µg/d, respectively. When the iodine content in salt was 30 and 35 mg/kg, for pregnant women, the total iodine intake was 296.8-408.9 µg/d, which was between the recommended nutrient intake and tolerable upper intake level. Therefore, in China, the iodine content in salt in the general population can be preset as 20, 25 and 30 mg/kg, and that in pregnant women 30 and 35 mg/kg, with a variation of ±5 mg/kg based on the automatic spraying technique used in the salt processing plant. Iodine nutritional status was then evaluated according to the preset iodine content in the salt, and it reached the appropriate level for the different populations. The iodine content in salt in China was decided and verified, and the procedure of selecting the iodine content in salt was established for the reference of different countries.

Household Water Is the Main Source of Iodine Consumption among Women in Hargeisa, Somaliland: A Cross-Sectional Study

BackgroundIodine status surveys of women in Somaliland present widely conflicting results. Previous research indicates elevated concentrations of iodine (IQR 18–72 μg/L) in groundwater used for drinking and cooking, but the relation with iodine intake is not well characterized. ObjectivesWe aimed to investigate the contributions of household water iodine concentration (WIC), breastfeeding, total fluid intake, hydration levels, and urine volume on urinary iodine concentration (UIC) and excretion (UIE) over a 24-h period and to define iodine status from iodine intake estimates and median UIC, normalized to a mean urine volume of 1.38 L/d (hydration adjusted). MethodsThe study sample comprised 118 nonpregnant, healthy women aged 15–69 y. All participants resided in Hargeisa, and 27 were breastfeeding. Data collection consisted of a 24-h urine collection, a 24-h fluid intake diary, a beverage frequency questionnaire, and a structured recall interview. We measured UIC and WIC in all urine and in 49 household water samples using the Sandell-Kolthoff reaction. ResultsWIC ranged between 3 and 188 μg/L, with significant median differences across the water sources and city districts (P < 0.003). Nonbreastfeeding women were borderline iodine sufficient [hydration-adjusted median urinary iodine concentration (mUIC) 109 μg/L; 95% CI: 97, 121 μg/L], whereas breastfeeding women showed a mild iodine deficiency (73 μg/L; 95% CI: 54, 90 μg/L). There were strong correlations (ρ: 0.50–0.69, P = 0.001) between WIC and UIC, with iodine from household water contributing more than one-half of the total iodine intake. Multivariate regression showed hydration and breastfeeding status to be the main predictors of UIC. ConclusionsIodine from household water is the main contributor to total iodine intake among women in Hargeisa, Somaliland. Variation in female hydration and spatial and temporal WIC may explain diverging mUIC between studies. Water sources at the extremes of low and high iodine concentrations increase the risk of subpopulations with insufficient or more than adequate iodine intake.

Iodine Intake from Food and Iodized Salt as Related to Dietary Salt Consumption in the Italian Adult General Population.

Since the Italian iodoprophylaxis strategy is based on the use of iodized salt, we assessed the relationship between dietary salt consumption and iodine intake in the Italian adult population. We estimated the relative contribution given by the use of iodized salt and by the iodine introduced by foods to the total iodine intake. The study population included 2219 adults aged 25–79 years (1138 men and 1081 women) from all Italian regions, participating to the Osservatorio Epidemiologico Cardiovascolare/Health Examination Survey 2008–2012 (OEC/HES), and examined for sodium and iodine intake in the framework of the MINISAL-GIRCSI Programme. Dietary sodium and total iodine intake were assessed by the measurement of 24 h urinary excretion, while the EPIC questionnaire was used to evaluate the iodine intake from food. Sodium and iodine intake were significantly and directly associated, upon accounting for age, sex, and BMI (Spearman rho = 0.298; p < 0.001). The iodine intake increased gradually across quintiles of salt consumption in both men and women (p < 0.001). The European Food Safety Authority (EFSA) adequacy level for iodine intake was met by men, but not women, only in the highest quintile of salt consumption. We estimated that approximately 57% of the iodine intake is derived from food and 43% from salt. Iodized salt contributed 24% of the total salt intake, including both discretionary and non-discretionary salt consumption. In conclusion, in this random sample of the Italian general adult population examined in 2008–2012, the total iodine intake secured by iodized salt and the iodine provision by food was insufficient to meet the EFSA adequate iodine intake.

Chinese Female Adults Need More Iodine Intake Based on ‘Overflow Theory’

Background: In China, there is a dearth of data on the iodine balance study for adults. Especially, due to the special physiological cycle, the research of female iodine balance is insufficient or lasts for a short time. In the present study, we spent more than two months to explore the basal iodine requirement based on healthy Chinese female adults and a new ‘iodine overflow’ theory was proposed for the study of iodine balance. Methods: A total of 36 Chinese healthy female adults (age 20.67 ± 1.10 years) were recruited for this study, which included 40 days low iodine depletion period and 6 stages of 30 days supplementation study. Uniform diets with different iodine content were provided, in which non-iodized salt and pure water were provided in all the meals and the content of iodine in the diet was regulated by accurately weighing dairy products with measured iodine content. The total iodine intake from food was collected using weighing and duplicate portion method and the total iodine excretion through 24-hour urine and staged faeces were completely gathered and monitored. The iodine content in diet, urine and feces were measured by ICP-MS. The iodine intake and excretion were calculated and a mixed effects models model was set up between incremental iodine intake and incremental iodine excretion based on the ‘iodine overflow’ theory. Findings: At the start of experiment, the 24h UIC was 233.31±122.47μg/L, which meant an iodine overnutrition for the majority of subjects. The iodine intake and excretion were 13.64μg/day and 48.58μg/day at the end of 1st stage. The incremental iodine intakes (Δ iodine intake) was 21.05, 39.64, 60.85, 88.16, 120.25μg/day and the incremental iodine excretion (Δ iodine excretion) was 25.75, 37.03, 54.67, 77.59, 105.43μg/day for the supplementation stages. According to the ‘iodine overflow’ hypothesis, the zero iodine balance (Δ iodine intake = Δ iodine excretion) derived from a mixed effect model indicated a mean iodine intake of 52.24μg/d(1.00μg/d•kg). The RNI for iodine to healthy Chinese female adult was 73.1μg/d(1.39μg/d•kg). Interpretation: Our findings indicate that basal iodine requirement may be much less than the current iodine intake recommendation. A daily iodine intake of 52.24μg/d may meet the basal iodine requirement for healthy Chinese female and Chinese women may need more than 20% iodine intake than men based on the ‘iodine overflow’ hypothesis. The ‘iodine overflow’ theory could provide a new idea for iodine balance research and the further studies should be needed for the iodine intake recommendation. Trial Registration: The trial was registered at the Chinese Clinical Trial Registry (No:ChiCTR1800016184). Funding: National Natural Science Foundation of China and Sanming Project of Medicine in Shenzhen. Declaration of Interest: The authors declare that they have no conflict of interest. Ethical Approval: This study was approved by the Ethical Committee of the National Institute for Nutrition and Health, Chinese Center for Disease Control and Prevention.

Relationship between salt consumption and iodine intake in a pediatric population

PurposeThe World Health Organization recommends reduction of salt intake to < 5 g/day and the use of iodized salt to prevent iodine deficiency states. A high prevalence of excess salt consumption and an inadequate iodine intake has been previously shown in an Italian pediatric population. It was appropriate, therefore, to analyse in the same population the relationship occurring between salt consumption and iodine intake.MethodsThe study population was made of 1270 children and adolescents. Estimates of salt consumption and iodine intake were obtained by measuring 24 h urinary sodium and iodine excretion.ResultsThe iodine intake increased gradually across quartiles of salt consumption independently of sex, age and body weight (p < 0.001). Median iodine intake met the European Food Safety Authority adequacy level only in teenagers in the highest quartile of salt consumption (salt intake > 10.2 g/day). We estimated that approximately 65–73% of the total iodine intake was derived from food and 27–35% from iodized salt and that iodized salt made actually only 20% of the total salt intake.ConclusionIn this pediatric population, in face of an elevated average salt consumption, the use of iodized salt was still insufficient to ensure an adequate iodine intake, in particular among teenagers. In the perspective of a progressive reduction of total salt intake, the health institutions should continue to support iodoprophylaxis, in the context of the national strategies for salt reduction. In order for these policies to be successful, in addition to educational campaigns, it is needed that the prescriptions contained in the current legislation on iodoprophylaxis are made compelling through specific enforcement measures for all the involved stakeholders.

Assessing the impact of drinking water iodine concentrations on the iodine intake of Chinese pregnant women living in areas with restricted iodized salt supply

The supply of non-iodized salt and the water improvement project have been conducted to reduce the iodine concentration in drinking water in areas with elevated water iodine. We aimed to assess the impact of water iodine concentration (WIC) on the iodine intake of pregnant women in areas with restricted iodized salt supply, and determine the cutoff values of WIC in areas with non-iodized salt supply. Overall, 534 pregnant women who attended routine antenatal outpatient visits in Zibo Maternal and Child Health Hospital in Gaoqing County were recruited. The 24-h urine iodine excretion (UIE) in 534 samples and the iodine concentration in 534 drinking water samples were estimated. Urinary iodine excretion, daily iodine intake, and daily iodine intake from drinking water (WII) were calculated. The relationship between WIC and daily iodine take was analyzed. The median WIC, spot urine iodine concentration (UIC), and 24-h UIE were 17 (6, 226) μg/L, 145 (88, 267) μg/L, and 190 (110, 390) μg/day, respectively. A significant positive correlation was found between WIC and UIE (R2 = 0.265, p < 0.001) and UIC (R2 = 0.261, p < 0.001). The contribution rate of WII to total iodine intake increased from 3.0% in the group with WIC of < 10μg/L to 45.7% in the group with WIC of 50-99μg/L. The iodine content in drinking water is the major iodine source in pregnant women living in high-water iodine areas where iodized salt supply is restricted. The contribution rate of daily iodine intake from drinking water increases with the increase in water iodine concentration.

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

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. 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. In Germany, only 42% (52.2µg/d) of the predicted median total iodine intake (126.2µg/d), i.e., 12% less than in Switzerland, were found to originate from salt, whereas 73.7µg/d came from iodine containing foods. 28% (2.6g/d) of the median salt intake (9.3g/d) of the German population was calculated to represent iodized salt against 43% in Switzerland. 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 25mg/kg to ensure iodine sufficiency in the population, whereas in Germany fortification still remains at a mean level of 20mg/kg implying a growing risk of increasing iodine deficiency rates if general salt intake drops.

Iodine intake among children and adolescents in Norway: Estimates from the national dietary survey Ungkost 3 (2015-2016)

BackgroundIodine is crucial for normal growth and neurodevelopment. Before 1950, goitre caused by iodine deficiency was widespread in Norway, but decreased significantly after mandatory fortification of animal fodder. Recent dietary changes in milk consumption and fish intake may again have increased the risk of inadequate intakes in some population groups in Norway. The situation for children and adolescents is unclear, and data from nationally representative studies are highly needed. We aimed to describe the iodine intake in Norwegian children and adolescents and estimate the proportion of individuals with an increased risk of suboptimal, adequate and excessive usual iodine intake. In addition, we aimed to investigate whether individuals’ characteristics were associated with iodine intake, and to identify the major iodine contributing foods in the diet of this population. MethodsData from 1722 individuals (4-, 9- and 13-year-olds) from a national dietary survey in Norway from 2015-2016 was used. Both descriptive and inferential statistics were conducted. Usual iodine intakes were estimated, stratified by age group and sex and compared to dietary reference intake cut-offs. Linear regression models were used to assess the association between iodine intake and participants’ characteristics. The contribution of iodine from different foods was described for all and across different participant groups. ResultsWe estimated that the proportion of participants with an increased risk of a suboptimal usual intake of iodine varied from 3-36%. A significant increased risk was observed for older children and girls compared to younger children and boys. Excessive usual intakes were not observed in any age group. Iodine intake was associated with sex, maternal educational level and area of residence. A lower intake was observed for girls and those with a mother with a low educational level. Moreover, those living in the western part and Mid-Norway had statistically significantly higher intakes compared to those living in the capital city and surroundings. Milk, milk products, cheese, fish and shellfish were the main contributors to iodine intake. Supplements contributed with very little of the total iodine intake. ConclusionsWe have shown that the estimated risk of suboptimal usual iodine intakes among children and adolescents in Norway varies according to age, sex, maternal educational level and area of residence. Those with a limited intake of the main dietary contributors to iodine intake may be at risk, and adolescent girls seem to be especially vulnerable.

Diagnosis of coronary artery disease in patients with atrial fibrillation using low tube voltage coronary CT angiography with isotonic low-concentration contrast agent.

This prospective study evaluated the image quality and accuracy of coronary computed tomography angiography (CCTA) for diagnosing coronary artery disease (CAD) in patients with atrial fibrillation (AF), in which CCTA used adaptive iterative dose reduction (AIDR) with a low tube voltage and low concentration of isotonic contrast agent. Sixty-eight consecutive patients with AF and suspected CAD were equally and randomly apportioned to two groups and underwent CCTA. In the experimental group, the contrast agent was iodixanol (270mgI/mL), patients were scanned with 100kV, and reconstruction was by AIDR. In the conventional scanning (control) group, the contrast agent was iopromide (370mgI/mL), patients were scanned with 120kV, and reconstruction was by filtered back projection. The image quality, effective radiation dose (E), and total iodine intake of the groups were compared. Thirty-nine patients with coronary artery stenosis later were given invasive coronary angiography (ICA). The groups were similar with regard to mean CT value, noise, and signal-to-noise and contrast-to-noise ratios. The figure of merit of the experimental group was significantly higher than that of the control group, while the E and total iodine were significantly lower. Using ICA as the diagnostic reference, the groups shared similar sensitivity, specificity, and false positive and false negative rates for diagnosing coronary artery stenosis. For determining CAD in patients with AF, CCTA with isotonic low-concentration contrast agent and low-voltage scanning is a feasible alternative that improves accuracy and reduces radiation dose and iodine intake.