Intelligence quotient and iodine intake: a cross-sectional study in children

Urinary iodine concentrations in preschoolers and cognitive development at 4 and 6 years of age, the Rhea mother-child cohort on Crete, Greece

BACKGROUND

Evidence regarding child iodine intake and neurodevelopment is scarce.

METHODS

We aimed to assess the impact of child iodine intake at 4 years of age on cognitive and motor development at 4 and 6 years among 304 children from the Rhea cohort on Crete, Greece. Child iodine intake was assessed via urinary iodine concentrations (UIC) measured using Inductively Coupled Plasma Mass Spectrometry (ICP-MS) and adjusted for specific gravity. Child cognitive and motor development was assessed using the McCarthy Scales of Children's Abilities (MSCA) at 4 years of age and Raven's Coloured Progressive Matrices (RCPM), Finger Tapping Test (FTT), and Trail Making Test (TMT) at 6 years. Associations were explored using multivariable-adjusted linear regression analyses with UIC categorized according to WHO criteria [insufficient intake <100 µg/L, adequate 100-299 µg/L (reference group), excessive ≥300 µg/L].

RESULTS

The children's median UIC was 249 µg/L (25-75th percentile: 181-344 μg/L). Children with UIC <100 μg/L had lower scores in the motor scale at 4 years (MSCA-motor scale: B=-10.3; 95 %CI -19.9, -0.6; n=10) and in intelligence at 6 years (RCPM-total score: B=-3.6, 95 %CI -6.8, -0.5; n=9) than children in the reference group. No associations were found with the general cognitive scale at 4 years or with TMT and FTT scales at 6 years. Children with UIC ≥300 μg/L had lower cognitive scores both at 4 (MSCA; B= -3.5; 95 %CI -6.9, -0.1; n =101) and 6 years of age (RCPM-total score; B= -1.2; 95 %CI -2.3, -0.0; n =98) than children in the reference group. No associations were observed with the motor scale at 4 years or with TMT and FTT scales at 6 years.

CONCLUSION

Our findings indicate that both low and excessive iodine intake at preschool age may adversely affect child cognitive abilities. Additionally, low iodine intake may also impact motor abilities.

Biometals in Alzheimer disease: emerging therapeutic and diagnostic potential of molybdenum and iodine

The current ageing trend of the world population has, in part, accounted for Alzheimer disease (AD) being a public health issue in recent times. Although some progress has been made in clarifying AD-related pathophysiological mechanisms, effective intervention is still elusive. Biometals are indispensable to normal physiological functions of the human body-for example, neurogenesis and metabolism. However, their association with AD remains highly controversial. Copper (Cu) and zinc (Zn) are biometals that have been investigated at great length in relation to neurodegeneration, whereas less attention has been afforded to other trace biometals, such as molybdenum (Mo), and iodine. Given the above context, we reviewed the limited number of studies that have evidenced various effects following the usage of these two biometals in different investigative models of AD. Revisiting these biometals via thorough investigations, along with their biological mechanisms may present a solid foundation for not only the development of effective interventions, but also as diagnostic agents for AD.

Association between Elevated Iodine Intake and IQ among School Children in Portugal

The goal of this work was to examine whether elevated iodine intake was associated with adverse effects on IQ among school-age children in Portugal. In a representative sample of children from the north of the country, IQ percentiles by age (assessed with Raven’s Colored Progressive Matrices) were dichotomized to <50 (“below-average” IQs) and ≥50. Morning urine iodine concentrations, corrected for creatinine, were dichotomized to <250 µg/g and ≥250 µg/g, according to the European Commission/Scientific Committee on Food’s tolerable upper level of daily iodine intake for young children. Data were examined with Chi-square tests, logistic regression, and GLM univariate analysis. The sample (N = 1965) was classified as generally iodine-adequate (median urinary iodine concentration = 129 µg/L; median iodine-to-creatinine ratio = 126 µg/g) according to the WHO’s criteria. A greater proportion of children in the ≥250 µg/g group had below-average IQs, compared to children with less than 250 µg/g (p = 0.037), despite a sizable (though non-significant) proportion of children in the less-than-250 µg/g group also presenting below-average IQs, at the bottom of the iodine distribution (<50 µg/g). The proportion of below-average IQs increased with increasingly elevated iodine concentrations (p = 0.047). The association remained significant after the adjustment for confounders, with the elevated iodine group showing increased odds of having below-average IQs when compared with the non-elevated iodine group (OR 1.55; 95% CI 1.11−2.17; p = 0.011). Consistently, the former group presented a lower mean IQ than the latter (p = 0.006). High iodine intake was associated with lower IQs even in a population classified as iodine-adequate. These results bear on child cognition and on initiatives involving iodine supplementation.

Can Nutrients and Dietary Supplements Potentially Improve Cognitive Performance Also in Esports?

Factors influencing brain function and cognitive performance can be critical to athletic performance of esports athletes. This review aims to discuss the potential beneficial effects of micronutrients, i.e., vitamins, minerals and biologically active substances on cognitive functions of e-athletes. Minerals (iodine, zinc, iron, magnesium) and vitamins (B vitamins, vitamins E, D, and C) are significant factors that positively influence cognitive functions. Prevention of deficiencies of the listed ingredients and regular examinations can support cognitive processes. The beneficial effects of caffeine, creatine, and probiotics have been documented so far. There are many plant products, herbal extracts, or phytonutrients that have been shown to affect precognitive activity, but more research is needed. Beetroot juice and nootropics can also be essential nutrients for cognitive performance. For the sake of players’ eyesight, it would be useful to use lutein, which, in addition to improving vision and protecting against eye diseases, can also affect cognitive functions. In supporting the physical and mental abilities of e-athletes the base is a well-balanced diet with adequate hydration. There is a lack of sufficient evidence that has investigated the relationship between dietary effects and improved performance in esports. Therefore, there is a need for randomized controlled trials involving esports players.

Relationship between salt consumption and iodine intake in a pediatric population

PURPOSE

The 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.

METHODS

The 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.

RESULTS

The 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.

CONCLUSION

In 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.

Iodine Intake Estimated by 24 h Urine Collection in the Italian Adult Population: 2008-2012 Survey

Monitoring the population iodine status is essential for iodine deficiency eradication. This study assessed the average dietary iodine intake and the iodine status of a random sample of the Italian general adult population. The study population included 2378 adults aged 35-79 years (1229 men and 1149 women) from all 20 Italian regions, participating in the Osservatorio Epidemiologico Cardiovascolare/Health Examination Survey 2008-2012 (OEC/HES), and were examined for iodine intake in the framework of the MINISAL-GIRCSI Programme. Dietary iodine intake was assessed by the measurement of 24 h urinary iodine excretion. The median daily iodine intake of the whole population was lower (96 µg/d, interquartile range 51-165) than the daily adequate iodine intake according to both EFSA and WHO recommendation (150 µg/d), with a significantly lower value among women (85 µg/d) compared with men (111 µg/d). Iodine intake diminished with age and increased with BMI (body mass index) in male but not in female participants, without achieving the adequate intake in any sex, age, or BMI category. In this random sample of Italian general adult population examined in 2008-2012, iodine intake still remained lower than the recommended values despite the implementation of a strategy of iodoprophylaxis based on salt iodization in 2005. These data represent a valuable reference for future monitoring of iodine status in our country.

Iodine nutrition: Disorders, monitoring and policies

Iodine is an essential mineral nutrient and an integral component of thyroid hormones. Iodine deficiency is typically associated with goiter, but can have more serious health implications. Adequate iodine status is important for normal brain development. Iodine deficiency in utero or in early life can cause severe neurological and cognitive impairment. Over the last three decades, global efforts have reduced the prevalence of iodine deficiency disorders (IDD) in many areas of the world with implementation of nutrition policies and programs such as "salt" iodization. However, in a number of areas iodine deficiency is still widespread. Iodine deficiency in remote regions with high poverty will be more difficult to eradicate. Efforts to eliminate IDD in affected areas and sustaining successful iodine programs will be a priority given the substantial public health and economic benefits. A key component will be periodic monitoring of population iodine status to ensure sufficient intakes and the absence of excessive intakes. Median urinary iodine concentration (UIC), a validated biomarker for assessing population iodine status, will facilitate monitoring. Research validating "usual" UIC for use in combination with the Estimated Average Requirement cut-point method will expand its utility and allow accurate determination of the prevalence of inadequate intakes in populations. Further research on the development of biomarkers for assessment of individual iodine status for routine patient care will be important.

Prediction of childhood brain outcomes in infants born preterm using neonatal MRI and concurrent clinical biomarkers (PREBO-6): study protocol for a prospective cohort study

INTRODUCTION

Infants born very preterm are at risk of adverse neurodevelopmental outcomes, including cognitive deficits, motor impairments and cerebral palsy. Earlier identification enables targeted early interventions to be implemented with the aim of improving outcomes.

METHODS AND ANALYSIS

Protocol for 6-year follow-up of two cohorts of infants born <31 weeks gestational age (PPREMO: Prediction of Preterm Motor Outcomes; PREBO: Prediction of Preterm Brain Outcomes) and a small term-born reference sample in Brisbane, Australia. Both preterm cohorts underwent very early MRI and concurrent clinical assessment at 32 and 40 weeks postmenstrual age (PMA) and were followed up at 3, 12 and 24 months corrected age (CA). This study will perform MRI and electroencephalography (EEG). Primary outcomes include the Movement Assessment Battery for Children second edition and Full-Scale IQ score from the Wechsler Intelligence Scale for Children fifth edition (WISC-V). Secondary outcomes include the Gross Motor Function Classification System for children with cerebral palsy; executive function (Behavior Rating Inventory of Executive Function second edition, WISC-V Digit Span and Picture Span, Wisconsin Card Sorting Test 64 Card Version); attention (Test of Everyday Attention for Children second edition); language (Clinical Evaluation of Language Fundamentals fifth edition), academic achievement (Woodcock Johnson IV Tests of Achievement); mental health and quality of life (Development and Well-Being Assessment, Autism Spectrum Quotient-10 Items Child version and Child Health Utility-9D).

AIMS

Examine the ability of early neonatal MRI, EEG and concurrent clinical measures at 32 weeks PMA to predict motor, cognitive, language, academic achievement and mental health outcomes at 6 years CA.Determine if early brain abnormalities persist and are evident on brain MRI at 6 years CA and the relationship to EEG and concurrent motor, cognitive, language, academic achievement and mental health outcomes.

ETHICS AND DISSEMINATION

Ethical approval has been obtained from Human Research Ethics Committees at Children's Health Queensland (HREC/19/QCHQ/49800) and The University of Queensland (2019000426). Study findings will be presented at national and international conferences and published in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

ACTRN12619000155190p. WEB ADDRESS OF TRIAL: http://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?ACTRN=12619000155190p.

Iodine nutrition status in Spain Needs for the future

Although iodine nutrition in Spain has improved in recent years, the problem is not completely resolved. It is necessary that health institutions establish measures to ensure an adequate iodine nutrition of the population, especially among the highest risk groups (children and adolescents, women of childbearing age, pregnant women and nursing mothers). A low salt intake should be advised, but it should be iodized. It is also imperative that food control agencies establish effective control over adequate iodization of salt. Indicators on iodine nutrition should be included in future health surveys. The EUthyroid study and the Krakow Declaration on iodine nutrition provide an opportunity to set up a pan-European plan for the prevention of iodine deficiency that should be considered and used by health authorities.

Iodine-fortified toddler milk improves dietary iodine intakes and iodine status in toddlers: a randomised controlled trial

PURPOSE

We aimed to evaluate the effectiveness of consuming iodine-fortified toddler milk for improving dietary iodine intakes and biochemical iodine status in toddlers.

METHODS

In a 20-week parallel randomised controlled trial, healthy 12-20-month-old children were assigned to: Fortified Milk [n = 45; iodine-fortified (21.1 µg iodine/100 g prepared drink) cow's milk], or Non-Fortified Milk (n = 90; non-fortified cow's milk). Food and nutrient intakes were assessed with 3-day weighed food records at baseline, and weeks 4 and 20. Urinary iodine concentration (UIC) was measured at baseline and 20 weeks.

RESULTS

At baseline, toddlers' median milk intake was 429 g/day. There was no evidence that milk intakes changed within or between the groups during the intervention. Toddlers' baseline geometric mean iodine intake was 46.9 µg/day, and the median UIC of 43 µg/L in the Fortified Milk group and 55 µg/L in the Non-Fortified Milk group indicated moderate and mild iodine deficiency, respectively, with this difference due to chance. During the intervention, iodine intakes increased by 136% (p < 0.001) and UIC increased by 85 µg/L (p < 0.001) in the Fortified Milk group compared to the Non-Fortified Milk group. The 20-week median UIC was 91 µg/L in the Fortified Milk group and 49 µg/L in the Non-Fortified Milk group.

CONCLUSIONS

Consumption of ≈ 1.7 cups of iodine-fortified toddler milk per day for 20 weeks can increase dietary iodine intakes and UIC in healthy iodine-deficient toddlers. This strategy alone is unlikely to provide sufficient intake to ensure adequate iodine status in toddlers at risk of mild-to-moderate iodine deficiency.

Is iodine nutrition in the Spanish pediatric population adequate? Historical review and current situation

Iodine is an essential component of thyroid hormones, and iodine deficit is the leading cause of preventable mental retardation worldwide. Spain was considered iodine-deficient until 2003. Although iodine urinary levels have been in the optimal range in Spain since 2004, the WHO recognizes that our country does not meet the necessary requirements to ensure that the whole population is not at risk of an iodine deficiency disorder. The aim of this article is to review the current iodine status in Spain. Data from several studies emphasize the low consumption of iodized salt at home. Despite the progress made in recent decades, Spanish children are not exempt from suffering an iodine deficiency disorder. Policies that allow for controlling iodine nutrition and promote universal consumption of iodized salt should therefore be implemented.

Iodine status in Norwegian preschool children and associations with dietary iodine sources: the FINS-KIDS study

Purpose

Iodine is an essential trace element necessary for thyroid hormone synthesis. Iodine deficiency is a continuing public health problem despite international efforts to eliminate it. Studies on iodine status in preschoolers are scarce. Thus, the aims of the current study were to determine the iodine status and to investigate possible associations between urinary iodine concentration (UIC) and estimated 24 h iodine extraction (UIE) and iodine-rich foods.

Methods

Data are cross-sectional baseline data, obtained from the two-armed randomized controlled dietary trial “Fish Intervention Studies-KIDS” (FINS-KIDS) conducted in Bergen, Norway. UIC was determined by inductively coupled plasma-mass spectrometry in spot urine samples. Inadequate UIC was defined as median < 100 µg/L, and low estimated 24 h UIE as < 65 µg/day. Habitual dietary intake was assessed by a short food frequency questionnaire. Logistic regression models were used to investigate possible associations between UIC and estimated 24 h UIE and iodine-rich dietary sources including seafood, dairy products and eggs. Iodine/creatinine ratio (I/Cr) was also estimated.

Results

Urinary spot samples were obtained from 220 children. The median (interquartile range) UIC and estimated 24 h UIE was 132 (96) µg/L, and 65 (55) µg/day, respectively. The majority of children had an estimated I/Cr ratio within 100–199 µg/g. Intake of sweet milk < 2 times/day versus ≥ 2 times/day was associated with UIC < 100 µg/L (OR 2.17, 95% CI 1.07–4.38, p = 0.031). Intake of dairy products (OR 3.59, 95% CI 1.13–11.43, p = 0.031) and sweet milk (OR 2.77, 95% CI 1.37–5.61, p = 0.005) < 2 times/day versus ≥ 2 times day was associated with estimated 24 h UIE < 65 µg/day.

Conclusions

The preschoolers had adequate iodine status. Low intake of sweet milk and dairy products were associated with low iodine status.

Frontiers in endocrine disruption: Impacts of organotin on the hypothalamus-pituitary-thyroid axis

Endocrine disruptors (EDs), chemical substances widely used in industry and ubiquitously distributed in the environment, are able to interfere with the synthesis, release, transport, metabolism, receptor binding, action, or elimination of endogenous hormones. EDs affect homeostasis mainly by acting on nuclear and nonnuclear steroid receptors but also on serotonin, dopamine, norepinephrine and orphan receptors in addition to thyroid hormone receptors. Tributyltin (TBT), an ED widely used as a pesticide and biocide in antifouling paints, has well-documented actions that include inhibiting aromatase and affecting the nuclear receptors PPARγ and RXR. TBT exposure in humans and experimental models has been shown to mainly affect reproductive function and adipocyte differentiation. Since thyroid hormones play a fundamental role in regulating the basal metabolic rate and energy homeostasis, it is crucial to clarify the effects of TBT on the hypothalamus-pituitary-thyroid axis. Therefore, we review herein the main effects of TBT on important metabolic pathways, with emphasis on disruption of the thyroid axis that could contribute to the development of endocrine and metabolic disorders, such as insulin resistance and obesity.

Assessment of iodine importance and needs for supplementation in school-aged children in Portugal

BACKGROUND

Micronutrients are essential for child proper growth and development. Nutritional deficiencies of these elements have increasingly been a concern in Europe, as they are often related to the cognitive potential and physical lifelong consequences. However, being an essential trace element for thyroid function, iodine intake in the desired quantities becomes also very important for neurodevelopment, including for school-aged children. Therefore, the aim of this paper is to highlight the need for wider dissemination of the physiological importance of iodine among health professionals and the general population as well as the knowledge of iodine needs and possible supplementation within families with school-aged children.

METHODS

The present study is an observational, descriptive, cross-sectional evaluation of knowledge and perceptions of iodine physiological importance. An evaluation survey has been carried out based on knowledge of iodine needs and possible supplementation within families with school-aged children. It has been target at mothers with school-age children under 18 years old with residence in Portugal. Data are represented as frequency and percentages and association between variables was measured.

RESULTS

The internet survey has been answered by around 691 mothers, corresponding to 811 children data validated; 47% (n = 381) girls and 53% (n = 430) boys. Mother's knowledge about iodine and the importance for the improvement of learning capacity is not independent of having health study/work area (χ2 at the 0.05 level). Nevertheless, it can be observed a slight association between mothers who agree with iodine supplementation and those who effectively supplement their child (χ2 9.315; Φ 0.116). Although use of iodized kitchen salt certainly changes the balance from sub-optimal to adequate iodine nutrition, only 8.8% (n = 61) reported using iodized salt. However, 87.6% (n = 605) assumed salt iodization importance without information.

CONCLUSIONS

We believe that the findings of this survey have great public health importance for Portugal. While many countries have mandatory iodizes salt programmes, in Portugal iodine supplementation is not a current practice. Therefore, we suggest an urgent evaluation of iodine in Portugal, namely for school-aged children, where iodine deficiencies are critical, as well as a systematic information dissemination as a form of publicizing iodine supplementation needs.

Suboptimal Iodine Concentration in Breastmilk and Inadequate Iodine Intake among Lactating Women in Norway

Breastfed infants depend on sufficient maternal iodine intake for optimal growth and neurological development. Despite this, few studies have assessed iodine concentrations in human milk and there is currently no published data on iodine status among lactating women in Norway. The aim of this study was to assess iodine concentrations in breast milk (BMIC) in lactating women and estimate iodine intake. Five Mother and Child Health Centres in Oslo were randomly selected during 2016, and 175 lactating women between 2nd and 28th weeks postpartum participated. Each of the women provided four breastmilk samples which were pooled and analysed for iodine concentrations. Participants also provided information on iodine intake from food and supplements covering the last 24 h and the habitual iodine intake (food frequency questionnaire). The median (p25, p75 percentiles) BMIC was 68 (45, 98) µg/L and 76% had BMIC <100 µg/L. Only 19% had taken an iodine-containing supplement during the last 24 h. The median 24 h iodine intake from food (p25, p75) was 121 (82, 162) µg/day and the total intake (food and supplements) was 134 (95, 222) µg/day. The majority of lactating women had suboptimal BMIC and inadequate intake of iodine from food and supplements.

Iodine Status and Growth In 0-2-Year-Old Infants With Cow's Milk Protein Allergy

OBJECTIVES

The aim of the present article was to investigate iodine status and growth in cow's milk protein allergic infants and to identify potential predictors of iodine status and growth.

METHODS

Fifty-seven infants under 2 years of age were included in an observational cross-sectional study. Two spot urine samples were collected and analyzed for iodine, together with a 3-day food record and a food frequency questionnaire. Urine iodine concentrations were compared with the WHO cut-off values for iodine deficiency. Measurements of weight, length, and head circumference at birth and study inclusion were converted to standard deviation scores. Subgroup analyses were performed on different feeding patterns, according to weaning status.

RESULTS

Median age was 9 months. Median urinary iodine concentration was 159 ug/L. One third of the children had urine iodine concentrations indicating iodine deficiency. Infants who were mainly breastfed were at highest risk and 58% were classified as deficient. Dietary factors positively associated with iodine excretion were intake of enriched baby cereals and meeting the dietary requirement for iodine. Stunting was present in 5%. Underweight and wasting was frequent at 11% and this was associated with food refusal and poor appetite, but not with iodine status. Growth failure was detected among boys.

CONCLUSIONS

The present study suggests that cow's milk protein allergy children have high prevalence of iodine deficiency and poor growth, however the 2 conditions were not associated. The subgroup of mainly breastfed infants was at higher risk of iodine deficiency compared to weaned infants. Subjects with feeding problems had increased risk of malnutrition.

Iodine Deficiency and the Brain: Effects and Mechanisms

Iodine is an essential micronutrient needed in human diets. As iodine is an integral component of thyroid hormone, it mediates the effects of thyroid hormone on brain development. Iodine deficiency is the most prevalent and preventable cause of mental impairment in the world. The exact mechanism through which iodine influences the brain is unclear, but is generally thought to begin with genetic expression. Many brain structures and systems appear to be affected with iodine deficiency, including areas such as the hippocampus, microstructures such as myelin, and neurotransmitters. The clearest evidence comes from the studies examining cognition in the cases of iodine deprivation or interventions involving iodine supplementation. Nevertheless, there are many inconsistencies and gaps in the literature of iodine deficiency, especially over the lifespan. This paper summarizes the literature on this topic, suggests a causal mechanism for iodine's effect on the brain, and indicates areas for the future research (e.g., using magnetic resonance imaging (MRI) and functional MRI to examine how iodine supplementation facilitates cognitive functioning).

Iodine deficiency a persisting problem: assessment of iodine nutrition and evaluation of thyroid nodular pathology in Portugal

BACKGROUND

The goal of eliminating iodine deficiency (ID) by the year 2000 has still not been achieved in several countries. More than 2 billion people worldwide (over 260 million school age children) remain ID. In Europe, there are still countries, such as Portugal, without national general population data on iodine nutrition (IN). This study aims at evaluating combined complementary data of the IN of the general population through urinary iodine concentration (UIC) and the thyroid histology profile from the inland region of Beira Interior (BI), in Portugal.

METHODS

UIC from a population sample of 214 volunteers (131 females and 83 males), with ages ranging from 8 to 97 years (mean 51.5 years ± SD 20.74 years), from BI was determined; the thyroid histology pattern in BI (6-year period) was evaluated; and the iodine content of the largest surface water reservoir of BI, never previously reported, was measured.

RESULTS

Median UIC of 62.6 μg/L was measured. Over 92 % of the population had UIC less than 100 μg/L. From 279 histology reports evaluated, the incidence of the different types of thyroid nodular pathology in BI was established. There were 60 histologic diagnoses of malignancy. The observed ratio of papillary to follicular carcinoma relatively close to 1 and the fairly high percentage of anaplastic carcinomas are characteristic of ID areas.

CONCLUSIONS

The findings of this first general population study on IN from the inland region of BI, Portugal, document significant ID. This problem, with its serious public health implications, could be corrected by having affordable iodised salt widely and generally available and by promoting a proactive population attitude generated by ample public information and educational programs as to the negative consequences of ID.

Effect of integrated school-based nutrition education on optimal dietary practices and nutritional status of school adolescents in Southwest of Ethiopia: a quasi-experimental study

BACKGROUND

Malnutrition and infection are major barriers to educational access and achievement in low-income countries and also work in conjunction with each other in deteriorating wellness and productivity of school adolescents.

METHODS

A quasi-experimental design was used to evaluate the effectiveness of school-based nutrition education using a peer-led approach, health promotion through school media and health clubs. Data were collected at baseline, midline and end line from sampled participants. To account for the effect of time trend, the difference was measured using a repeated measure analysis. Variables that have p≤0.25 in the bivariate analyses were entered into multivariables to determine the independent effect of interventions.

RESULTS

There is a significant difference in food variety between food secure and insecure households (p<0.01). A significant improvement of animal source dietary intake was observed among intervention schools (p<0.001) that was significantly associated with an intervention [adjusted odds ratio (AOR)=0.26, confidence interval (CI): 0.16, 0.42], male gender (AOR=0.48, CI: 0.31, 0.73) and household economic status (AOR=1.69, CI: 1.01, 2.84). The control group had high body mass index (BMI) at baseline, but a significant improvement was observed among the intervention schools, which positively associated with male gender (AOR=4.13, CI: 2.38, 7.15) and having a middle-income family (AOR=2.93, CI: 1.92, 6.15).

CONCLUSION

This study showed that by integrating a dietary intervention into school-based activities, there might be significant improvements in dietary intake of primary school adolescents. Therefore, school-based nutrition education programs should be a part of comprehensive school health programs to reach the students and potentially their families.

Normative Thyroid-Stimulating Hormone Values for Healthy Nigerian Newborns

BACKGROUND

Congenital hypothyroidism is a common congenital endocrine disorder prevailing all over the world. No nationwide screening exists for any sub-Saharan country. We present normative cord and capillary thyroid-stimulating hormone (TSH) values for healthy Nigerian newborns.

SUBJECTS AND METHODS

A cross-sectional study was carried out in 6 university hospitals in Nigeria between January 1 and December 31, 2013. Cord and heel blood placed on 4 concentric circles on a Whartman filter paper were analysed for TSH within 1 week of collection using AutoDelfia 1235 immunoassay (Perkin Elmer Wallace, Boston, Mass., USA) at Charité - Universitätsmedizin Berlin, Berlin, Germany. The mean TSH levels of the newborns were determined, considering their sex, birthweight, socioeconomic status, and birth city. The association between the mean TSH level and other parameters was determined by analysis of variance.

RESULTS

A total of 2,014 subjects were recruited during the study period. The mean TSH value for the subjects was 1.86 μIU/ml, and 98.1% of the newborns were within the 2.5th and 97.5th percentiles (range: 0.09-7.90 μIU/ml) of the TSH levels. We collected 247 cord and 1,767 heel samples, respectively, and the range was slightly higher in samples from cord blood.

CONCLUSION

The study highlights the normal reference values for capillary/cord TSH levels in term Nigerian newborns. TSH was higher in one region, attributable to earlier sampling, but was not influenced by gender, socioeconomic status, or birthweight.

Recent data on iodine intake in Germany and Europe

Iodine is essential for the synthesis of thyroid hormones. These regulate metabolism, promote growth, development and maturation of all organs, especially the brain. Most iodine is found in oceans and most continental soil and ground water is deficient in iodine. Therefore, around 2 billion individuals are estimated to have insufficient iodine intake and are at risk of iodine deficiency disorders. The best carrier for save iodine supplementation is salt, as the daily intake of salt is mainly constant. Due to the collaboration between international and national organisations and the salt industry, many developing and developed countries introduced universal salt iodization (USI) or have mandatory or voluntary fortification programs. In Germany as in most European countries the use of iodized salt is voluntary not only in household but also in the food industry. Two recent epidemiological surveys in Germany revealed that 33% of children and 32% of adults are still suffering from mild to moderate iodine deficiency. The best surrogate parameter for iodine deficiency is goitre. The goitre prevalence is around 30% in children as well as in adults which is in accordance with the documented iodine deficiency. From other European countries epidemiological derived data on iodine intake are only available from Denmark and Poland. Further efforts are under way to reveal the iodine status with proper methods in all European countries. On this background it might be possible to establish adequate iodine fortification programs in all European countries.

Relationship Between Iodine Concentration in Maternal Colostrum and Neurobehavioral Development of Infants in Shanghai, China

It is well known that iodine plays an important role in the process of early growth and development of most organs, especially the brain. However, iodine concentration in the colostrum and its association with the neurobehavioral development of infants remains unclear. Colostrums from 150 women were collected, and their iodine concentrations were measured. The median colostrum iodine level was 187.8 μg/L. The Bayley Scales of Infant and Toddler Development-III test was performed when the infants were about 18 months. The mean cognitive, language, and motor composite scores were 105.3 ± 9.8, 105.2 ± 11.1, and 104.6 ± 6.7, respectively. And the mean scores of the 5 subtests were 11.1 ± 2.0, 9.3 ± 2.0, 12.4 ± 2.3, 11.1 ± 1.2, and 10.4 ± 1.2, respectively. No statistically significant difference was observed in the cognition, language, or motor development of infants across different levels of colostrum iodine. After adjusting for a range of confounding factors, colostrum iodine concentration was a predictor of motor development, specifically gross motor development.

Evaluation of the effects of iodized salt on the mental development of preschool-aged children: a cluster randomized trial in northern Ethiopia

A cluster randomized effectiveness trial was used to examine the effects on mental development of introducing iodized salt to children 4 to 6 years of age in Ethiopia, where there were reportedly high levels of iodine deficiency. Sixty district clusters were randomized to receive iodized salt early at their markets with assistance from regular salt distributors or later as introduced by market forces. At pre- and post-iodization, 1602 children were given cognitive/language tests (namely School Readiness, WPPSI verbal reasoning, WPPSI Matrix reasoning), and mothers were interviewed concerning demographics, nutrition and health. Children's weight, height, urine and a blood sample were taken. Analyses of covariance, adjusting for clustering and baseline levels were conducted. Urinary iodine concentrations were significantly higher at endline in the intervention children than controls though both medians were above threshold. Overall, less than 5% were anemic. There were no significant main effect differences between groups on the cognitive/language tests, but there were effect modifiers, namely mother's education, child's sex and diet. For example, the intervention group performed better on the school readiness test than controls if their mothers had attended school, but not otherwise. In conclusion, the data are consistent with negative findings from studies where children 6 to 12 years were supplemented with an iodine capsule, indicating that the benefits of iodine, in salt or capsule form, for brain development may be restricted to children under 3 years. Yet, benefits may be tied to those with more educational resources or may compensate for conditions of disadvantage.

The challenge of long-term tetrahydrobiopterin (BH4) therapy in phenylketonuria: Effects on metabolic control, nutritional habits and nutrient supply

BACKGROUND AND AIMS

BH4-sensitive phenylketonuria (PKU) patients relax their phenylalanine (Phe) restricted diet due to increased Phe tolerance, while keeping dried blood Phe concentrations with in the therapeutic range. We aimed to investigate metabolic control, eating habits and nutrient supply under long-term BH4-therapy.

PATIENTS AND METHODS

Retrospective analysis of mean dried blood Phe concentrations and their variability, food and nutrient intake in BH4-sensitive patients (n = 8, 3f, age 6.0-16.6 y) under classical dietary treatment for one year and during the three years after initiation of BH4.

RESULTS

Phe concentrations of BH4-sensitve PKU patients remained within therapeutic range throughout the observation period, independent of therapeutic regime. Under BH4, Phe tolerance increased significantly (493.2 ± 161.8 mg/d under classical diet vs 2021.93 ± 897.4 mg/d two years under BH4; P = 0.004). Variability of Phe concentrations remained unchanged (mean SD; P = 1.000). Patients adjust their food choice and significantly increased their intake of cereals, potatoes, dairy products and meat (P = 0.019, P = 0.016, P = 0.016 and P = 0.016, respectively). Under diet changes after implementation of BH4 a drop in micronutrient intake (vitamin D, folic acid, iron, calcium, iodine) could be revealed (P = 0.005, P < 0.001, P = 0.004, P = 0.001, P = 0.003, respectively).

CONCLUSIONS

BH4-sensitive PKU patients can achieve good metabolic control under an adjuvant BH4- or a BH4 monotherapy. The liberalized diet under BH4 seems to jeopardize the quality of patients' nutrition, and these patients require close follow-up and special nutrition education to minimize the risk for imbalanced diet and nutrient deficiencies.

Assessment of iodine nutritional status in the general population in the province of Jaén

BACKGROUND AND OBJECTIVE

Iodine deficiency affecting both pregnant women and schoolchildren has been reported in Jaén. Iodine deficiency is one of the leading causes of thyroid dysfunction and goiter, and adequate iodine prophylaxis with iodized salt, milk, and dairy products, or iodine supplementation have been shown to significantly improve iodine status in pregnancy. The purpose of this study was to assess iodine nutritional status in the general population of a iodine-deficient area with no previous institutional campaigns of iodine prophylaxis.

MATERIAL AND METHODS

A descriptive, cross-sectional study. Urinary iodine levels were measured in subjects from the Jaén healthcare district. The data were stratified by sex and age groups, and a survey was conducted on iodized salt consumption.

RESULTS

Median and mean urinary iodine levels were 110.59 mcg/L and 130.11 mcg/L respectively. Urinary iodine levels were significantly higher in schoolchildren as compared to other age groups (161.52μg/L vs 109.33μg/L in subjects older than 65 years). Forty-three percent of the population had urinary iodine levels less than 100μg/L, and 68% of women of childbearing age had levels less than 150μg/L.

CONCLUSIONS

Iodine nutritional status appears to be adequate, but the proportion of the population with urinary iodine levels less than 100μg/L is still very high, and iodized salt consumption is much less common than recommended by the WHO.

Iodine deficiency and thyroid nodular pathology--epidemiological and cancer characteristics in different populations: Portugal and South Africa

BACKGROUND

The prevalence and pathology pattern of iodine deficiency (ID) related disorders are influenced by the dietary iodine intake: low iodine leads to thyroid nodular enlargement, to an increase in the incidence of thyroid cancer, an increase in anaplastic carcinomas and to an alteration in the papillary to follicular neoplasia ratio. This study aims at highlighting the effects of ID by comparatively evaluating the pattern of thyroid nodular pathology in different populations that, although geographically distant and heterogeneous, both had iodine deficiency at the time of data gathering and are at high altitude: Beira Interior (BI) in Portugal and Johannesburg (JHB) in South Africa. (S.A.) Mandatory salt iodization introduced in S. A. in 1995 has recently been shown to have resulted in the correction of ID.

METHODS

Evaluation of thyroid histology reports over a 6 year period in BI and a 5 year period in the JHB area.

RESULTS

Region of BI: 278 patients with histology reports-60 were malignancies (21.2 %): 31 papillary carcinomas, 22 follicular cancers (18 follicular carcinomas and 4 Hürthle cell tumours), 3 medullary carcinomas and 4 anaplastic carcinomas. Region of JHB: 136 histology reports- 33 were malignancies (24.3 %): 13 papillary carcinomas, 15 follicular cancers (10 follicular carcinomas and 5 Hürthle cell tumours), 1 medullary carcinoma, 3 anaplastic carcinomas and 1 metastatic carcinoma into the thyroid. There was an overlap in the frequencies of all histology types, of particular relevance in the relatively high anaplastic carcinoma incidences and in the papillary to follicular carcinoma ratios which was close to 1 in both areas- BI area ratio: 1.4 and JHB area ratio: 0.87, with overlapping 95 % CI's, also confirmed by the results of the chi-square calculations.

CONCLUSIONS

During the study periods evaluated both study areas displayed pathology patterns usually found in ID. Public information regarding the negative consequences of ID combined with the availability of affordable iodized salt are likely to achieve the goal of the elimination of ID. Sea based nutrition, (naturally iodine containing), may also contribute to the elimination of ID, particularly at times when salt restriction tends to be generally advised.

Dietary ratio of animal:plant protein is associated with 24-h urinary iodine excretion in healthy school children

Adequate dietary iodine intake in children is essential for optimal physical and neurological development. Whether lower dietary animal food and salt intake may adversely affect iodine status is under discussion. We examined the association between dietary animal:plant protein ratio with 24-h urinary iodine excretion (24-h UI, μg/d), and whether this is modified by salt intake. A 24-h UI was measured in 1959 24-h urine samples from 516 6- to 12-year-old participants of the Dortmund Nutritional and Anthropometric Longitudinally Designed Study. Parallel 3 d weighed food records were used to estimate dietary intakes. Protein sources were classified as dairy, animal and plant. A repeated-measures regression model (PROC MIXED) was used to analyse the effect of animal:plant protein ratios on 24-h UI.

ANIMAL

plant protein ratios ranged from 0.5 (95 % CI 0.4, 0.6) to 1.6 (95 % CI 1.4, 1.9) (lowest and highest quartile). After adjustment for total energy intake, main dietary iodine sources (dairy and salt intake), and further covariates, the inter-individual variation in animal:plant protein ratio was significantly associated with variation in 24-h UI. One unit higher animal:plant protein ratio predicted 6 μg/d higher 24-h UI (P= 0.002) in boys and 5 μg/d (P= 0.03) in girls. This relationship was partially mediated by a higher salt intake at higher animal:plant protein ratios. These results suggest that lower consumption of animal protein is associated with a small decline in iodine excretion, partially mediated by decreased salt intake. Because limited salt and increased intake of plant-based foods are part of a preferable healthy food pattern, effective nutrition political strategies will be required in the future to ensure appropriate iodine nutrition in adherent populations.

Thyroid status and its association with cognitive functioning in healthy boys at 10 years of age

OBJECTIVE

Thyroid hormones (THs) are crucial for the correct maturation of the CNS and the neurodevelopment of the child. We aimed to investigate the association of TSH and free thyroxine (FT4) levels with cognitive functioning in children from the INMA-Granada cohort studied during their follow-up at the age of 9-11 years.

DESIGN

We evaluated 300 children from the original cohort, which comprised 668 eligible mother-son pairs recruited at birth from 2000 to 2002 in Granada (Spain).

METHODS

FT4 and TSH concentrations were measured, and cognitive development was assessed using neuropsychological tests (n=187). Children with chronic disease related to thyroid function and/or cognitive development were excluded.

RESULTS

Median TSH and FT4 levels were 3.1 μIU/ml and 1.2 ng/dl respectively. In multivariable regression analyses adjusted for maternal and child characteristics, children with TSH levels in the top tertile had worse verbal comprehension and immediate and long-term recall. Children with FT4 levels in the top tertile had better attention and lower impulsivity and were at a lower risk of scoring below the 20th percentile in intelligence quotient (OR=0.24; 95% CI=0.08-0.74; P=0.013) and in abstract reasoning ability (OR=0.28; 95% CI=0.09-0.88; P=0.029).

CONCLUSION

Our findings indicate that circulating THs and TSH may in the top tertile have an impact on cognitive functions; thus, higher TSH slightly but significantly increased the risk of a lower score in certain neuropsychological tests.

Prevalence of iodine inadequacy in Switzerland assessed by the estimated average requirement cut-point method in relation to the impact of iodized salt

OBJECTIVE

To assess the iodine status of Swiss population groups and to evaluate the influence of iodized salt as a vector for iodine fortification.

DESIGN

The relationship between 24 h urinary iodine and Na excretions was assessed in the general population after correcting for confounders. Single-day intakes were estimated assuming that 92 % of dietary iodine was excreted in 24 h urine. Usual intake distributions were derived for male and female population groups after adjustment for within-subject variability. The estimated average requirement (EAR) cut-point method was applied as guidance to assess the inadequacy of the iodine supply.

SETTING

Public health strategies to reduce the dietary salt intake in the general population may affect its iodine supply.

SUBJECTS

The study population (1481 volunteers, aged ≥15 years) was randomly selected from three different linguistic regions of Switzerland.

RESULTS

The 24 h urine samples from 1420 participants were determined to be properly collected. Mean iodine intakes obtained for men (n 705) and women (n 715) were 179 (sd 68.1) µg/d and 138 (sd 57.8) µg/d, respectively. Urinary Na and Ca, and BMI were significantly and positively associated with higher iodine intake, as were men and non-smokers. Fifty-four per cent of the total iodine intake originated from iodized salt. The prevalence of inadequate iodine intake as estimated by the EAR cut-point method was 2 % for men and 14 % for women.

CONCLUSIONS

The estimated prevalence of inadequate iodine intake was within the optimal target range of 2-3 % for men, but not for women.

Evolution of urinary iodine excretion over eleven years in an adult population

BACKGROUND & AIMS

Few prospective cohort studies have evaluated dietary iodine intake and urinary iodine concentrations in the general adult population. We assess the evolution of urinary iodine excretion and factors that may influence it in an adult population followed for 11 years.

METHODS

A population-based cohort study was undertaken in Pizarra (Spain). In the three study phases (baseline (n = 886), and 6 (n = 788) and 11 years later (n = 501)), participants underwent an interview and a standardized clinical examination that included a food questionnaire, and thyroid hormone and urinary iodine determinations. Subjects with thyroid dysfunction, palpable goiter or urinary iodine excretion >400 μg/L were excluded.

RESULTS

Urinary iodine increased over the years (100.6 ± 70.0 μg/L at baseline vs. 125.4 ± 95.2 μg/L at 6 years and 141.6 ± 81.4 μg/L at 11 years; p < 0.0001). Urinary iodine was significantly higher in subjects who reported iodized salt consumption and in subjects with a higher intake of dairy products (p < 0.05). Consumption of iodized salt (Risk ratio (RR) = 1.23, 95% CI [1.01-2.05]) and dairy products (RR = 2.07, 95% CI [1.01-4.23]), and a baseline urinary iodine concentration ≥100 μg/L (RR = 1.26, 95% CI [1.04-1.53]) were significantly associated with urinary iodine concentrations ≥100 μg/L at 11 years. There is no correlation between thyroid function (TSH, free triiodothyronine or free thyroxine levels) and urinary iodine concentrations in conditions of iodine sufficiency.

CONCLUSIONS

The increase in urinary iodine concentrations over eleven years is associated with an increase in iodized salt intake and with the dairy products intake, and possibly with a higher iodine content of dairy products. However, individual variability in urinary iodine excretion was not fully explained by dietary iodine intake alone; previous urinary iodine concentrations were also important.

Iodine insufficiency in pregnant women from the State of São Paulo

Objective : The intake of adequate amounts of iodine during pregnancy is essential for the neurological development of the fetus. The aim of this study was to assess iodine nutrition status in pregnant women from the state of São Paulo, Brazil.Material and methods : We analyzed urinary iodine concentration (UIC) in 191 pregnant and 58 non-pregnant women matched by age. We used the World Health Organization criteria to define sufficient iodine supply (median UIC: 150-249 µg/L among pregnant women, and 100-199 µg/L for non-pregnant women).Results : Median UIC of the pregnant women studied was lower than the recommended value (median = 137.7 µg/L, 95% CI = 132.9 – 155.9), while non-pregnant women had UIC levels within the appropriate range (median = 190 μg/L; 95% IC = 159.3-200.1). UIC was below 150 µg/L in 57% of the pregnant women.Conclusions : Although a larger sample is needed to consolidate these findings, these results raise concerns about the adequacy of the iodine supply of pregnant women in Brazil, especially considering the new determinations of the Brazilian government, which have recently reduced the concentrations of iodine in table salt to 15-45 mg/kg of salt. Arq Bras Endocrinol Metab. 2014;58(3):282-7

The Na+/I- symporter (NIS): mechanism and medical impact

The Na(+)/I(-) symporter (NIS) is the plasma membrane glycoprotein that mediates active I(-) transport in the thyroid and other tissues, such as salivary glands, stomach, lactating breast, and small intestine. In the thyroid, NIS-mediated I(-) uptake plays a key role as the first step in the biosynthesis of the thyroid hormones, of which iodine is an essential constituent. These hormones are crucial for the development of the central nervous system and the lungs in the fetus and the newborn and for intermediary metabolism at all ages. Since the cloning of NIS in 1996, NIS research has become a major field of inquiry, with considerable impact on many basic and translational areas. In this article, we review the most recent findings on NIS, I(-) homeostasis, and related topics and place them in historical context. Among many other issues, we discuss the current outlook on iodide deficiency disorders, the present stage of understanding of the structure/function properties of NIS, information gleaned from the characterization of I(-) transport deficiency-causing NIS mutations, insights derived from the newly reported crystal structures of prokaryotic transporters and 3-dimensional homology modeling, and the novel discovery that NIS transports different substrates with different stoichiometries. A review of NIS regulatory mechanisms is provided, including a newly discovered one involving a K(+) channel that is required for NIS function in the thyroid. We also cover current and potential clinical applications of NIS, such as its central role in the treatment of thyroid cancer, its promising use as a reporter gene in imaging and diagnostic procedures, and the latest studies on NIS gene transfer aimed at extending radioiodide treatment to extrathyroidal cancers, including those involving specially engineered NIS molecules.

Maternal fatty acids in pregnancy, FADS polymorphisms, and child intelligence quotient at 8 y of age

BACKGROUND

Brain tissue is selectively enriched with highly unsaturated fatty acids (FAs). Altering the maternal FA status in pregnancy may improve fetal neural development with lasting consequences for child development.

OBJECTIVE

We explored whether maternal FAs in erythrocytes, either measured directly or indirectly by maternal FADS genetic variants, are associated with child intelligence quotient (IQ).

DESIGN

Linear regression analyses, adjusted for 18 confounders, were used to investigate the associations in 2839 mother-child pairs from the population-based Avon Longitudinal Study of Parents and Children cohort.

RESULTS

Low levels of arachidonic acid (20:4n-6) were associated with lower performance IQ (-2.0 points; 95% CI: -3.5, -0.6 points; P = 0.007, increased R² = 0.27%), high levels of osbond acid (22:5n-6) were associated with verbal IQ (-1.8 points; 95% CI: -3.2, -0.4 points; P = 0.014, R² = 0.20%), and high levels of adrenic acid (22:4n-6) were associated with verbal IQ (-1.7 points; 95% CI:-3.1, -0.3 points; P = 0.016, R² = 0.19%). There was some evidence to support a negative association of low docosahexaenoic acid (DHA; 22:6n-3) with full-scale IQ (R² = 0.15%). Novel weak associations were also observed for low levels of osbond acid (R² ≤ 0.29%) and FADS variants with opposite effects for intron variants and variants in the promoter region such as rs3834458 (R² ≤ 0.38%).

CONCLUSIONS

These results support the positive role of maternal arachidonic acid and DHA on fetal neural development, although the effects on child IQ by 8 y of age were small (0.1 SD), with other factors contributing more substantially. The endogenous synthesis of these FAs by FADS genes, especially FADS2, may also be important. The replication of these results is recommended.

The size of the community rather than its geographical location better defines the risk of iodine deficiency: results of an extensive survey in Southern Italy

AIM

The objective of this study was to establish the status of iodine nutrition in Southern Italy.

MATERIAL AND METHODS

The survey was carried out on 11-14 yr old children attending primary school and living in urban and non urban areas of 8 regions of Southern Italy. Urinary iodine excretion (UIE) was measured in 23,103 urinary samples randomly collected.

RESULTS

Median UIE in the whole studied population was 74 μg/l [interquartile range (IR) 34-139 μg/l]. UIE was significantly higher in chief towns compared to non chief towns (81 μg/l, IR 39-145 μg/l vs 73 μg/l, IR 33-138 μg/l, p<0.0001) and in areas with >500 inhabitants per km² (median 87 μg/l, IR 43-154 μg/l) compared to areas with 100-500 per km² (median 66 μg/l, IR 29-126 μg/l, p<0.0001) and with <100 per km² (median 61 μg/l, IR 25-121 μg/l, p<0.0001). Median UIE was significantly lower in inland mountainous/hilly areas (68 μg/l, IR 30-129 μg/l) compared to coastal mountainous/hilly areas (79 μg/l, IR 37-144 μg/l, p<0.0001) and lowland (79 μg/l, IR 37-146 μg/l, p<0.0001). According to a binary logistic regression model, population density was the only independent parameter significantly associated with UIE ≥ 100 μg/l.

CONCLUSION

The results of the present survey indicate that: 1) in Southern Italy mild to moderate iodine deficiency is still present; 2) median UIE in non urban areas is lower than in urban areas and is related to the size of the community rather than to its geographical location, being higher in a larger community. This may be due to better diversification of dietary habits and the easier availability of iodized salt and processed food through commercial facilities, more common in larger communities. Future monitoring surveys should take into account these observations.

Infant neurocognitive development is independent of the use of iodised salt or iodine supplements given during pregnancy

The benefits of iodine supplements during pregnancy remain controversial in areas with a mild-to-moderate iodine deficiency. The aim of the present study was to determine the effect of improving iodine intakes, with iodised salt (IS) or iodine supplements, in pregnant Spanish women. A total of 131 pregnant women in their first trimester were randomly assigned to three groups: (1) IS in cooking and at the table, (2) 200 μg potassium iodide (KI)/d or (3) 300 μg KI/d. No differences were found in thyroid-stimulating hormone (TSH), free thyroxine (FT4), free triiodothyronine (FT3) or thyroid volume (TV) between the three groups. Regardless of the group in which women were included, those who had been taking IS for at least 1 year before becoming pregnant had a significantly lower TV in the third trimester (P= 0.01) and a significantly higher urinary iodine in the first (173.7 (sd 81.8) v. 113.8 (sd 79.6) μg/l, P= 0.001) and third trimesters (206.3 (sd 91.2) v. 160.4 (sd 87.7) μg/l, P= 0.03). Also, no differences were seen in TSH, FT4 or FT3. Children's neurological development was not significantly associated with the consumption of IS for at least 1 year before becoming pregnant and no differences were found according to the treatment group. In conclusion, in pregnant women with insufficient iodine intake, the intake of IS before becoming pregnant was associated with a better maternal thyroid function. The form of iodide intake was not associated with maternal thyroid function or children's neurological development.

Iodine status in preschool children and evaluation of major dietary iodine sources: a German experience

PURPOSE

Even mild iodine deficiency may negatively affect cognitive performance, especially at a young age. Our aim was to investigate iodine status in very young children and to assess the importance of iodized salt in processed foods of which the use has decreased during the last years in Germany.

METHODS

Twenty-four hours urinary iodine excretion (UIE) as a marker of iodine intake was measured in 378 24 h urine samples collected 2003-2010 by 221 3 to <6 years old participants of the DONALD Study. Parallel 3-d weighed dietary records and measurements of urinary sodium excretion provided data on the daily consumption of the most important iodine sources in the children's diet (iodized salt, milk, fish, meat and eggs). Time trends of UIE (2003-2010) and contributions of the different food groups were analyzed by using linear mixed-effects regression models.

RESULTS

Median UIE of 71 μg/d in boys and 65 μg/d in girls (P = 0.03), corresponding to an iodine intake of 82 and 75 μg/d, respectively (assumption: 15% non-renal iodine losses), was below the recommended dietary allowance (RDA) of 90 μg/d. Milk, salt and egg intake were significant predictors of UIE; milk and salt together accounted for >80% of iodine supply. Between 2003 and 2010, UIE decreased significantly by approximately 1 μg/d per year. The contribution of salt intake to UIE decreased from 2003-2006 to 2007-2010.

CONCLUSION

In countries where salt is a major iodine source, already modest decreases in the iodized proportion of salt used in processed foods may relevantly impair iodine status even in preschool children.

Iodine intake in human nutrition: a systematic literature review

The present literature review is a part of the NNR5 project with the aim of reviewing and updating the scientific basis of the 4th edition of the Nordic Nutrition Recommendations (NNR) issued in 2004. The main objective of the review is to assess the influence of different intakes of iodine at different life stages (infants, children, adolescents, adults, elderly, and during pregnancy and lactation) in order to estimate the requirement for adequate growth, development, and maintenance of health. The literature search resulted in 1,504 abstracts. Out of those, 168 papers were identified as potentially relevant. Full paper selection resulted in 40 papers that were quality assessed (A, B, or C). The grade of evidence was classified as convincing, probable, suggestive, and no conclusion. We found suggestive evidence for improved maternal iodine status and thyroid function by iodine supplementation during pregnancy. Suggestive evidence was found for the relationship between improved thyroid function (used as an indicator of iodine status) during pregnancy and cognitive function in the offspring up to 18 months of age. Moderately to severely iodine-deficient children will probably benefit from iodine supplementation or improved iodine status in order to improve their cognitive function, while only one study showed improved cognitive function following iodine supplementation in children from a mildly iodine-deficient area (no conclusion). No conclusions can be drawn related to other outcomes included in our review. There are no new data supporting changes in dietary reference values for children or adults. The rationale for increasing the dietary reference values for pregnant and lactating women in the NNR5 needs to be discussed in a broader perspective, taking iodine status of pregnant women in the Nordic countries into account.

Iodine intake and prevalence of thyroid autoimmunity and autoimmune thyroiditis in children and adolescents aged between 1 and 16 years

OBJECTIVES

To determine the status of iodine nutrition in children and adolescents in Almería, Spain. To calculate prevalence of thyroid autoimmunity (TA) and autoimmune thyroiditis (AT) in pediatric ages and to research into associated factors.

METHODS

Cross-sectional epidemiological study. By a multistage probability sampling 1387 children and adolescents aged between 1 and 16 were selected. Physical examination was carried out including neck palpation. Parents were asked about eating habits as well as about social and demographic aspects. Urinary iodine, free thyroxine, TSH, antiperoxidase and antithyroglobulin antibodies were measured. TA was diagnosed when any antibody was positive and AT when autoimmunity was associated with impaired thyroid function or goitre. Results are shown using percentages (and its 95% confidence interval). To study associated factors we used multiple logistic regression, quantifying the relation with odds ratio (OR), and multiple lineal regression.

RESULTS

Median urinary iodine concentration was 199.5 μg/l. The prevalences of TA and AT were 3.7% (2.4-5.0) and 1.4% (0.4-2.4). TA is associated with female sex (OR 2.78; P<0.001) and age (OR 1.30; P<0.001). Iodine status is associated with the intake of milk and dairy product (P<0.001) and vegetable (P=0.021) but not with use of iodized salt at home (P=0.1).

CONCLUSIONS

The iodine supply in children and adolescents in our city is optimal. Milk and dairy products are the most important iodine sources. TA and AT are prevalent in pediatric ages in our city mainly in females and older subjects.

Changes in iodine nutrition status in schoolchildren from the Basque Country

BACKGROUND

An epidemiologic survey showed in 1992 iodine deficiency and endemic goiter in schoolchildren from the Basque Country.

OBJECTIVES

(1) To determine the percentage of homes of schoolchildren where iodized salt (IS) is used; (2) to assess iodine nutrition status in schoolchildren and to compare the data collected to those available from previous epidemiological studies.

DESIGN AND METHODS

A cross-sectional study in 720 randomly selected schoolchildren. Urinary iodine concentration (UIC) was measured using high-performance liquid chromatography(HPLC) with electrochemical detection.

RESULTS

IS was used at 53.0% of the homes (95% confidence interval [CI], 49.2-56.7%). Median UIC has increased by 226%, from 65 μg/L in 1992 to 147 μg/L (percentile [P], P(25), 99 μg/L; P(75), 233 μg/L) today. Both schoolchildren consuming IS and those using unfortified salt at their homes had UICs corresponding to adequate iodine intakes (165 and 132 μg/L respectively). UICs experienced great seasonal fluctuations, being 55% higher during the November-February period than in June-September period (191 μg/L vs 123 μg/L; p<0.001)

CONCLUSIONS

Schoolchildren from the Basque Country have normalized their iodine nutrition status. The strong seasonal pattern of UICs suggests that consumption of milk and iodine-rich dairy products coming from cows feed iodized fodder is one of the most significant factors involved in the increase in iodine intake since 1992.

Summary of an NIH workshop to identify research needs to improve the monitoring of iodine status in the United States and to inform the DRI

The Office of Dietary Supplements (ODS) at the NIH sponsored a workshop on May 12-13, 2011, to bring together representatives from various NIH institutes and centers as a first step in developing an NIH iodine research initiative. The workshop also provided an opportunity to identify research needs that would inform the dietary reference intakes for iodine, which were last revised in 2001. Iodine is required throughout the life cycle, but pregnant women and infants are the populations most at risk of deficiency, because iodine is required for normal brain development and growth. The CDC monitors iodine status of the population on a regular basis, but the status of the most vulnerable populations remains uncertain. The NIH funds very little investigator-initiated research relevant to iodine and human nutrition, but the ODS has worked for several years with a number of other U.S. government agencies to develop many of the resources needed to conduct iodine research of high quality (e.g., validated analytical methods and reference materials for multiple types of samples). Iodine experts, scientists from several U.S. government agencies, and NIH representatives met for 2 d to identify iodine research needs appropriate to the NIH mission.

A comprehensive assessment of urinary iodine concentration and thyroid hormones in New Zealand schoolchildren: a cross-sectional study

Background

Insufficient iodine in children’s diets is of concern because thyroid hormones are needed for normal growth and development, particularly of the brain. This study aimed to carry out a comprehensive assessment of the iodine status of New Zealand schoolchildren using a range of biochemical indices suitable for populations (i.e. urinary iodine concentration) and individuals (i.e. thyroid hormones).

Methods

The New Zealand National Children’s Nutrition Survey was a cross­‒sectional survey of a representative sample of schoolchildren aged 5­‒14 years. Children were asked to provide a casual urine sample for the determination of urinary iodine concentration (UIC) and a blood sample for the determination of thyroglobulin (Tg), Thyroid Stimulating Hormone (TSH), free thyroxine (fT4) and free triiodothyronine (fT3).

Results

The median UIC was 68 μg/L (n = 1153), which falls between 50­‒99 μg/L indicative of mild iodine deficiency. Furthermore, 29% of children had an UIC <50 μg/L and 82% had an UIC <100 μg/L. The median Tg concentration was 12.9 μg/L, which also falls between 10.0­‒19.9 μg/L indicative of mild iodine deficiency. The Tg concentration of children with an UIC <100 μg/L was 13.9 μg/L, higher than the 10.3 μg/L in children with an UIC >100 μg/L (P = 0.001). The mean TSH (1.7 mU/L), fT4 (14.9 pmol/L), and fT3 (6.0 pmol/L) concentrations for these mildly iodine deficient New Zealand children fell within normal reference ranges.

Conclusions

The UIC and Tg concentration indicate that New Zealand schoolchildren were mildly iodine deficient according to WHO/UNICEF/ICCIDD, and both are suitable indices to assess iodine status in populations or groups. The normal concentrations of TSH, fT4 and fT3 of these children suggest that these thyroid hormones are not useful indices of mild iodine deficiency.

Iodine intake in the adult population. Di@bet.es study

BACKGROUND & AIMS

To date no nation-wide study has yet been undertaken in Spain to estimate the iodine deficiency. The aim was to evaluate iodine intake and its conditioning factors in a representative sample of the whole adult population.

METHODS

The Di@bet.es Study is a national, cross-sectional, population-based survey conducted in 2009-2010 in Spain.

RESULTS

The median urinary iodine (UI) was 117.2 μg/L. Iodized salt (IS) was consumed by 43.9% of the population. The median UI in those who consumed IS and in those who did not consume IS was 131.1 and 110.8 μg/L respectively (p<0.0001). The likelihood of having UI levels above 100 μg/L was significantly associated with the intake of IS (OR=1.47) and milk at least once a day (OR=1.22). Within each individual autonomous communities, the median UI levels in those who consumed IS correlated significantly with the median levels of those who did not consume IS (r=0.76, p=0.001).

CONCLUSIONS

Though strictly speaking, Spain should be considered within the category of a country having an adequate iodine intake, the current value is too close to the cut point and does not guarantee that those groups with a greater need for iodine will have the required intake of iodine.