Iodine supplementation improves cognition in iodine-deficient schoolchildren in Albania: a randomized, controlled, double-blind study

Essential micronutrients in children and adolescents with a focus on growth and development: a narrative review

This comprehensive review examines the crucial role of micronutrients in the health of children and adolescents, focusing on their growth and development. Micronutrients, including vitamins and trace elements, are essential for various biochemical processes and biological functions. We explored the roles, assessment methods, deficiency patterns, and intervention strategies for six essential micronutrients: iron, zinc, vitamin A, vitamin D, iodine, and folate. These nutrients were selected based on their fundamental importance in pediatric development. By analyzing the current literature from PubMed, Embase, and Web of Science databases, we synthesized findings regarding the impact of these micronutrients on health outcomes in children and adolescents, examining both regional and global prevalence data, with particular attention paid to Korean population data. This review provides evidence-based insights into the assessment and management of micronutrient status in children and adolescents and offers recommendations for clinical practice.

The correlation between the thyroid function and urinary iodine/creatinine ratio of pregnant women attending a tertiary hospital in Beijing, China, during different trimesters

OBJECTIVE

This study investigated the correlation between thyroid function and urinary iodine/creatinine ratio (UI/Cr) in pregnant women during different trimesters and explored potential influencing factors.

METHODS

In this cross-sectional study, serum levels of thyroid-stimulating hormone (TSH), free triiodothyronine (FT3), free thyroxine (FT4), and UI/Cr were measured in 450 pregnant women. Correlations were analyzed using Pearson's correlation coefficient and multiple linear regression. Subgroup analyses were performed based on age, body mass index (BMI), parity, gestational age, education, occupation, and family history of thyroid disorders.

RESULTS

UI/Cr was positively correlated with FT4 levels in the first and second trimesters, particularly in women with older age, higher BMI, multiparity, higher education, and employment. No significant correlations were found between UI/Cr and TSH or FT3 levels.

CONCLUSION

UI/Cr is positively correlated with FT4 levels in early pregnancy, especially in women with certain risk factors. Regular monitoring of iodine status and thyroid function is recommended for pregnant women to ensure optimal maternal and fetal health.

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.

Thyroid function and iodine intake: global recommendations and relevant dietary trends

Iodine is a micronutrient that is essential for thyroid hormone production. Adequate iodine intake is especially important during pregnancy and early life, when brain development is dependent on thyroid hormones. Iodine intake recommendations vary around the world, but most recommendations generally reflect the increased requirements during pregnancy and lactation, although adequate iodine intake before pregnancy is also important. Tremendous progress has been made in improving iodine intake across the world over the past 30 years, mainly through salt-iodization programmes. However, in countries without strong iodine fortification programmes, and with shifts in dietary patterns, a need has arisen for health organizations, governments and clinicians to ensure that adequate iodine is consumed by everyone in the population. For example, in countries in which adequate iodine intake depends on individual food choice, particularly of iodine-rich milk and dairy products, intake can be highly variable and is also vulnerable to changing dietary patterns. In this Review, iodine is considered in the wider context of the increasing prevalence of overweight and obesity, the dietary trends for salt restriction for cardiovascular health and the increasing uptake of plant-based diets.

A multi-sectoral community development intervention has a positive impact on diet quality and growth in school-age children in rural Nepal

Poor diet quality (diet diversity and animal-source food [ASF] consumption) during childhood negatively affects growth, development, behaviour and physiologic function in later life. Relatively less is known about the impact of poor diet on the growth of school-age children compared to children <5 years of age, especially in low/middle-income countries. A better understanding of delivery strategies for effective interventions to improve diet and hence growth in school-age children is needed. A 36-month longitudinal controlled impact evaluation in rural Nepal assessed the nutrition and growth of children <5 years of age in families assigned via community clusters to full package intervention (community development, training in nutrition [during pregnancy and for children <5 years] and livestock husbandry), partial package (training only) or control (no inputs). Concurrent data were collected prospectively (baseline plus additional four rounds) on school-age children (5-8 years at baseline) in these households; the present study analysed findings in the cohort of school-age children seen at all five study visits (n = 341). Diet quality improved more in the full package school-age children compared to those in partial package or control households. full package children consumed more ASF (β +0.40 [CI 0.07,0.73], p < 0.05), more diverse diets (β +0.93 [CI 0.55,1.31], p < 0.001) and had better head circumference z-scores (β +0.21 [CI 0.07,0.35], p < 0.01) than control children. In conclusion, a multi-sectoral community development intervention was associated with improvements in diet and growth of school-age children in rural Nepal even though the intervention focused on the diet of children <5 years of age. The diet and growth of school-age children can be favourably influenced by community-level interventions, even indirectly.

Association between urinary iodine excretion, genetic disposition and fluid intelligence in children, adolescents and young adults: the DONALD study

PURPOSE

Iodine deficiency increases the risk of cognitive impairment and delayed physical development in children. It is also associated with cognitive impairment in adults. Cognitive abilities are among the most inheritable behavioural traits. However, little is known about the consequences of insufficient postnatal iodine intake and whether the individual genetic disposition modifies the association between iodine intake and fluid intelligence in children and young adults.

METHODS

The cultural fair intelligence test was used to assess fluid intelligence in the participants of the DONALD study (n = 238; mean age, 16.5 [SD = 7.7] years). Urinary iodine excretion, a surrogate iodine intake marker, was measured in 24-h urine. Individual genetic disposition (n = 162) was assessed using a polygenic score, associated with general cognitive function. Linear regression analyses were conducted to determine whether Urinary iodine excretion was associated with fluid intelligence and whether this association was modified by individual genetic disposition.

RESULTS

Urinary iodine excretion above the age-specific estimated average requirement was associated with a five-point higher fluid intelligence score than that below the estimated average requirement (P = 0.02). The polygenic score was positively associated with the fluid intelligence score (β = 2.3; P = 0.03). Participants with a higher polygenic score had a higher fluid intelligence score.

CONCLUSION

Urinary iodine excretion above the estimated average requirement in childhood and adolescence is beneficial for fluid intelligence. In adults, fluid intelligence was positively associated with a polygenic score for general cognitive function. No evidence showed that the individual genetic disposition modifies the association between Urinary iodine excretion and fluid intelligence.

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.

Estimation of appropriate dietary intake of iodine among lactating women in China based on iodine loss in breast milk

OBJECTIVE

Data on iodine loss in breast milk, which are critical for establishing the appropriate dietary iodine intake for lactating women, is currently limited. A study was conducted to assess iodine loss in breast milk among Chinese lactating women to estimate the appropriate dietary intake of iodine.

METHODS

A total of 54 pairs of healthy, lactating women and their infants aged 0-6 months were recruited from Tianjin and Luoyang cities in China. A 4 days infant weighing study was conducted to assess iodine loss in the breast milk of lactating women. Mothers were required to weigh and record their infants' body weights before and after each feeding for a 24 h period from 8:00 am to 8:00 am. During the weighing study, 2812 breast milk samples and 216 24-h urine samples were collected from each lactating mother for four consecutive days. In addition, a 3 days 24 h dietary record, including salt weighing and drinking water samples collecting, was performed by each lactating mother to determine dietary iodine intake during the weighing study.

RESULTS

The average dietary iodine intake of lactating women was 323 ± 80 μg/d. The median breast milk iodine concentration and 24 h urinary iodine concentration of lactating women were 154 (122-181) and 135 (104-172) μg/L, respectively. The mean volume of breast milk and the mean iodine loss in the breast milk of lactating women were 711 ± 157 mL/d and 112 ± 47 μg/d, respectively. The appropriate dietary intake of iodine among lactating Chinese women is approximately 260 µg/d.

CONCLUSIONS

Based on the iodine loss in breast milk (110 μg/d) found in this study, and the estimated average requirement of iodine for adults, the appropriate dietary intake of iodine among lactating Chinese women is 260 µg/d, which is higher than the 240 μg/d recommended by the China Nutrition Science Congress in 2013.

Optimizing Growth: The Case for Iodine

Iodine is an essential micronutrient and component of thyroid hormone. An adequate dietary iodine intake is critical to maintain and promote normal growth and development, especially during vulnerable life stages such as pregnancy and early infancy. The role of iodine in cognitive development is supported by numerous interventional and observational studies, and when iodine intake is too low, somatic growth is also impaired. This can be clearly seen in cases of untreated congenital hypothyroidism related to severe iodine deficiency, which is characterized, in part, by a short stature. Nevertheless, the impact of a less severe iodine deficiency on growth, whether in utero or postnatal, is unclear. Robust studies examining the relationship between iodine and growth are rarely feasible, including the aspect of examining the effect of a single micronutrient on a process that is reliant on multiple nutrients for optimal success. Conversely, excessive iodine intake can affect thyroid function and the secretion of optimal thyroid hormone levels; however, whether this affects growth has not been examined. This narrative review outlines the mechanisms by which iodine contributes to the growth process from conception onwards, supported by evidence from human studies. It emphasizes the need for adequate iodine public health policies and their robust monitoring and surveillance, to ensure coverage for all population groups, particularly those at life stages vulnerable for growth. Finally, it summarizes the other micronutrients important to consider alongside iodine when seeking to assess the impact of iodine on somatic growth.

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.

Iodine Intake and Related Cognitive Function Impairments in Elementary Schoolchildren

Iodine deficiency, the most common cause of preventable mental impairment worldwide, has been linked to poorer intellectual function in several studies. However, to our knowledge, no studies have been performed in moderate iodine-deficient schoolchildren using the complete form of Wechsler Intelligence Scale for Children (WISC-III; Portuguese version). The main purpose of this study was to ascertain whether moderate iodine deficiency would affect the cognitive function of schoolchildren (7-11 years old; 3rd and 4th grades). Raven's Colored Progressive Matrices (CPM; Portuguese version) were used for measuring the intelligence quotient (IQ) of the total population (n = 256; median UIC = 66.2 μg/L), and the WISC-III was used to study two selected subgroups: one moderately iodine-deficient (n = 30) and the other with adequate iodine intake (n = 30). WISC-III was shown to be the prime instrument for cognitive function assessment among moderate iodine-deficient schoolchildren; this subgroup had a Full-Scale IQ 15.13 points lower than the adequate iodine intake subgroup, with a magnitude effect of d = 0.7 (p = 0.013). Significant differences were also registered in 6 of the 13 Verbal-Performance IQ subtests. Moderate iodine deficiency has a substantial impact on mental development and cognitive functioning of schoolchildren, with significant impairment in both Performance IQ and Verbal IQ spectrum, adversely impacting their educational performance.

Impact of malnutrition on the academic performance of school children in Ethiopia: A systematic review and meta-analysis

Objective

This study aimed to identify the impact of malnutrition on the academic performance of children in Ethiopia.

Method

The protocol of this study is registered in PROSPERO with a registration number CRD42021242269. A comprehensive search of studies from HINARY, MEDLINE (via PubMed), EMBASE, Cochrane Library, SCOPUS, Google Scholar, and Google was conducted. All published and unpublished studies conducted about the effect of any forms of malnutrition on academic performance of elementary school children in Ethiopia using the English language were included. Quality of the articles was assessed using the Joanna Briggs Institute critical appraisal tool. The pooled log odds ratio with 95% confidence interval was determined to identify the effect of malnutrition on academic performance. I-square statistics was applied to check the degree of heterogeneity between studies. The presence of publication or small study bias had been assessed by Funnel plots, Egger's weighted regression test, and Begg's rank correlation test.

Result

A total of 10 studies were included in this study. The pooled prevalence of good academic performance among elementary school students in Ethiopia was 58% (95% confidence interval: 48%, 69%). Stunting (odds ratio = 0.48; 95% confidence interval: 0.30, 0.79), underweight (odds ratio = 0.38; 95% confidence interval: 0.27, 0.53), and iodine deficiency (odds ratio = 0.49; 95% confidence interval: 0.31, 0.78) had a significant association with the academic performance. Rural residence (odds ratio = 0.61; 95% confidence interval: 0.44, 0.83), being female (odds ratio = 0.53; 95% confidence interval: 0.37, 0.77), and uneducated parent (odds ratio = 0.51; 95% confidence interval: 0.44, 0.58) were also factors associated with good academic performance of primary school children in Ethiopia.

Conclusion

This study concluded that malnutrition in the form of stunting, underweight, and iodine deficiency affected the academic performance of elementary school children in Ethiopia. So, the Ministry of Health worked better to strengthen the nutrition intervention at the critical periods of brain development.

Gestational and childhood urinary iodine concentrations and children's cognitive function in a longitudinal mother-child cohort in rural Bangladesh

BACKGROUND

Severe iodine deficiency adversely affects neurodevelopment; however, evidence regarding the association of non-severe deficiency and child cognitive functioning is inconclusive.

METHODS

This prospective mother-child cohort study was nested in a population-based nutritional supplementation trial in Bangladesh (Maternal and Infant Nutrition Interventions in Matlab [MINIMat]). Participants with data on cognitive abilities at 5 and 10 years of age (n = 1530) and at least one measurement of urinary iodine concentration (UIC) (gestational week 8, 5, and 10 years) were selected. Cognitive abilities were assessed using the Wechsler Preschool and Primary Scale of Intelligence (WPPSI-III) and Wechsler Intelligence Scale for Children (WISC-IV). UICs were measured with inductively coupled plasma mass spectrometry and thereafter adjusted for specific gravity.

RESULTS

Median UICs in our population: (282 μg/L [pregnancy]; 406 μg/L [5 years]; 294 μg/L [10 years]) indicated that iodine intake corresponded to above 'adequate' or even 'excessive', according to the WHO classification. Maternal 'UIC <150 μg/L' was associated with lower full-scale and verbal scores at 5 and 10 years, although the associations were weakened in the fully adjusted models. A tendency of decreased verbal scores was also observed for maternal 'UIC ≥500 μg/L' but not for the corresponding child iodine category (≥300 μg/L). Child 'UIC <100 μg/L' was associated with lower processing speed (B=-3.1, 95% CI [-6.2, -0.1]; P-value = 0.041) compared with the reference group (100 μg/L≤ UIC <300 μg/L).

CONCLUSIONS

Current findings add to the growing evidence of a causal association of early-life iodine intake with cognitive development, indicating that low iodine intake during childhood is associated with reduced processing speed and non-optimal gestational iodine intake is weakly associated with slightly poorer verbal development outcomes.

Is the urinary iodine/creatinine ratio applicable to assess short term individual iodine status in Chinese adults? Comparison of iodine estimates from 24-h urine and timed-spot urine samples in different periods of the day

Background

Urinary iodine concentration (UIC) is routinely used to evaluate the population iodine status while the uniform method for the individual level assessment is uncertain.

Objectives

To explore the 24-h urinary iodine excretion (UIE) in five different periods of the day and the corresponding prediction equations respect by the use of creatinine-corrected UIC.

Methods

We collected 24-h, spot and fasting urine in five periods of the day to estimate 24-h UIE by the six different prediction equations. We compared the estimated creatinine-corrected UIC to the collected 24-h UIE and identified the most suitable equations in each period of the day.

Results

Among the six different prediction equations, the equation of Kawasaki T was the best to estimate the 24-h UIE by fasting urine among Chinese adults. Among the five periods of time, the equation of Knudsen N was the best to estimate the 24-h UIE in the non-morning period.

Conclusion

Urinary iodine status at the individual level could be estimated by different creatinine-based equations at different periods of the day.

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.

Nutrients for executive function development and related brain connectivity in school-aged children

Executive functions refer to a set of higher-order cognitive processes involved in the control and organization of information to serve goal-directed behaviors. Skills in executive functioning are developed throughout childhood and adolescence and have been shown to be predictive of academic achievement. The coordination of these complex processes is critically dependent on brain maturation and connectivity, including key neurodevelopmental processes like myelination and synaptogenesis. Among other factors, research highlights the influential effect of nutrition and diet on these neurodevelopmental processes, which may impact executive function performance in healthy and deficient populations. This review considers the research to date on the role of key nutrients that have been identified for executive function development and their underlying neurophysiological processes in school-aged children.

Association of dietary diversity and cognition in preschoolers in rural China

OBJECTIVES

We sought to investigate the cognition of preschoolers in rural China and examine the relationship between dietary diversity and cognition.

METHODS

We performed a cross-sectional survey analysis. In 1334 preschoolers ages 3 to 5, from 26 preschools in two nationally designated poverty counties in Hunan Province in China, we calculated the dietary diversity score (DDS) using a 24-h recall method. To measure children's cognitive ability, we assessed the Working Memory Index and Verbal Comprehension Index on the Mandarin-language version of the Wechsler Preschool and Primary Scale of Intelligence, Fourth Edition. Multiple linear regression models were used to estimate the association between DDS and cognitive test scores.

RESULTS

A total of 22% of children had a Working Memory Index that was either extremely low or borderline, and 31% of children had a Verbal Comprehension Index that was either extremely low or borderline. The mean (± SD) DDS was 5.65 ± 1.30. Those preschoolers with medium DDS (5 or 6) or high DDS (7 to 9) scored higher on both Working Memory Index-respectively, mean difference (MD), 1.327; 95% confidence interval (CI), 0.246-3.901; and MD, 2.067, 95% CI, 0.261-4.641-and Verbal Comprehension Index-MD, 0.168; 95% CI, 0.072-2.135; and MD, 0.398; 95% CI, 0.032-2.137-than did those with low DDS (0 to 4).

CONCLUSIONS

Consuming a more diverse diet may contribute to better cognition in preschoolers. Future research is needed to better understand the possible causal effect of dietary diversity on cognitive development.

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.

Ten2Twenty-Ghana: Study Design and Methods for an Innovative Randomized Controlled Trial with Multiple-Micronutrient-Fortified Biscuits among Adolescent Girls in Northeastern Ghana

Investing in adolescent girls' nutrition is vital for health and for breaking the intergenerational cycle of malnutrition and deprivation, but limited knowledge on the type, timing, and efficacy of interventions delays progress. We describe the design of a 26-wk randomized placebo-controlled trial with multiple-micronutrient-fortified biscuits (MMBs) among adolescent girls in northeastern Ghana. Apparently healthy, premenarche (n = 312) and postmenarche (n = 309) girls (10-17 y) were randomly assigned to receive the following for 5 d/wk: 1) MMBs (fortified with 11 vitamins and 7 minerals) or 2) unfortified biscuits. Data included plasma micronutrient status, anthropometry, body composition, cognitive function, psychosocial health, fertility, dietary intake, and sociodemographic and socioeconomic covariates, complemented with in-depth interviews (n = 30) and 4 focus group discussions. We hypothesized an increase in plasma ferritin and retinol-binding protein with a resultant increase in hemoglobin, cognition, vertical height, and psychosocial health. Our study seeks to investigate the efficacy and optimal timing of a multiple-micronutrient food intervention program for adolescent girls. The RCT was registered prospectively with the Netherlands Clinical Trials Register (NL7487).

A systematic review and meta-analysis of 24-h urinary output of children and adolescents: impact on the assessment of iodine status using urinary biomarkers

PURPOSE

Urinary iodine concentration (UIC (μg/ml) from spot urine samples collected from school-aged children is used to determine the iodine status of populations. Some studies further extrapolate UIC to represent daily iodine intake, based on the assumption that children pass approximately 1 L urine over 24-h, but this has never been assessed in population studies. Therefore, the present review aimed to collate and produce an estimate of the average 24-h urine volume of children and adolescents (> 1 year and < 19 years) from published studies.

METHODS

EBSCOHOST and EMBASE databases were searched to identify studies which reported the mean 24-h urinary volume of healthy children (> 1 year and < 19 years). The overall mean (95% CI) estimate of 24-h urine volume was determined using a random effects model, broken down by age group.

RESULTS

Of the 44 studies identified, a meta-analysis of 27 studies, with at least one criterion for assessing the completeness of urine collections, indicated that the mean urine volume of 2-19 year olds was 773 (654, 893) (95% CI) mL/24-h. When broken down by age group, mean (95% CI) 24-h urine volume was 531 mL/day (454, 607) for 2-5 year olds, 771 mL/day (734, 808) for 6-12 year olds, and 1067 mL/day (855, 1279) for 13-19 year olds.

CONCLUSIONS

These results demonstrate that the average urine volume of children aged 2-12 years is less than 1 L, therefore, misclassification of iodine intakes may occur when urine volumes fall below or above 1 L. Future studies utilizing spot urine samples to assess iodine status should consider this when extrapolating UIC to represent iodine intakes of a population.

The association of urine markers of iodine intake with development and growth among children in rural Uganda: a secondary analysis of a randomised education trial

OBJECTIVE

We examined associations of urine iodide excretion, proxy for iodine intake, with child development and growth.

DESIGN

This is a secondary analysis of a 1:1 cluster-randomised trial with a 6-month nutrition/stimulation/hygiene education intervention among mothers of children aged 6-8 months to improve child development and growth. Development was assessed using Bayley Scales of Infant and Toddler Development-III (BSID-III) and Ages and Stages Questionnaire (ASQ), whereas anthropometry was used to assess growth. Urine iodide concentration (UIC) and urine iodide/creatinine ratio (ICR) were measured.

SETTING

The current study was conducted in southern Uganda.

PARTICIPANTS

We randomly selected 155 children from the 511 enrolled into the original trial and analysed data when they were aged 20-24 and 36 months.

RESULTS

Median UIC for both study groups at 20-24 and 36 months were similar (P > 0·05) and within the normal range of 100-199 µg/l (0·79-1·60 µmol/l), whereas the intervention group had significantly higher ICR at 20-24 months. The BSID-III cognitive score was positively associated (P = 0·028) with ICR at 20-24 months in the intervention group. The ASQ gross motor score was negatively associated (P = 0·020) with ICR at 20-24 months among the controls. ICR was not significantly associated with anthropometry in the two study groups at either time-point.

CONCLUSIONS

Following the intervention, a positive association was noted between ICR and child's cognitive score at 20-24 months, whereas no positive association with ICR and growth was detected. Iodine sufficiency may be important for child's cognitive development in this setting.

An Integrated Infant and Young Child Feeding and Small-Quantity Lipid-based Nutrient Supplementation Program Is Associated with Improved Gross Motor and Communication Scores of Children 6-18 Months in the Democratic Republic of Congo

OBJECTIVE

To evaluate the impact of an infant, young child feeding practices-small-quantity lipid nutrient supplements (SQ-LNS) intervention on child development scores in children aged 6-18 months in the Katanga Province, Democratic Republic of Congo (DRC).

STUDY DESIGN

We analyzed data of 2595 children from 2 health zones in a quasi-experimental design with preimplementation and postimplementation surveys to evaluate program impact on child development scores. Standard care was received in the comparison health zone and the intervention health zone received standard care plus enhanced infant, young child feeding practices with a monthly supply of 28 SQ-LNS sachets for up to 1 year. Program exposure and communication and motor domains of the Ages and Stages questionnaire were collected to assess changes in child development scores. A quasi-intent-to-treat and adjusted difference-in-difference analyses were used to quantify impact of the enhanced compared with the standard package.

RESULTS

In adjusted models contrasting endline with baseline, there was a greater relative increase in proportion of children with normal communication (difference-in-difference, +13.7% [95%CI, 7.9-19.6; P < .001] and gross motor scores, +7.4% [95% CI: 1.3-13.5; P < .001]) in the intervention vs comparison health zones. Further, in separate analyses among children of intervention health zone at endline, each additional SQ-LNS distribution was associated with +0.09 (95% CI, 0.03-0.16) z-score unit increase in gross motor scores (P < .01).

CONCLUSIONS

The integrated infant, young child feeding practice-SQ-LNS intervention was positively associated with larger relative improvements in measures of child communication and motor development in the Katanga province of DRC.

Current iodine nutrition status in Poland (2017): is the Polish model of obligatory iodine prophylaxis able to eliminate iodine deficiency in the population?

OBJECTIVE

The monitoring of the populations' iodine status is an essential part of successful programmes of iodine deficiency elimination. The current study aimed at the evaluation of current iodine nutrition in school children, pregnant and lactating women as a marker of the effectiveness and sustainability of mandatory iodine prophylaxis in Poland.

DESIGN

The following iodine nutrition indicators were used: urinary iodine concentration (UIC) (all participants) and serum thyroglobulin (pregnant and lactating women).

SETTING

The study was conducted in 2017 within the National Health Programme in five regions of Poland.

PARTICIPANTS

The research included 300 pregnant women, 100 lactating women and 1000 school children (aged 6-12 years).

RESULTS

In pregnant women, median UIC was 111·6 µg/l; there was no significant difference in median UIC according to the region of residence. In 8 % of pregnant women, thyroglobulin level was >40 ng/ml (median thyroglobulin 13·3 ng/ml). In lactating women, median UIC was 68·0 µg/l. A significant inter-regional difference was noted (P = 0·0143). In 18 % of breastfeeding women, thyroglobulin level was >40 ng/ml (median thyroglobulin 18·5 ng/ml). According to the WHO criteria, the investigated sample of pregnant and lactating women was iodine-deficient. Median UIC in school children was 119·8 µg/l (with significant inter-regional variation; P = 0·0000), which is consistent with iodine sufficiency. Ninety-four children (9·4 %) had UIC < 50 µg/l.

CONCLUSIONS

Mandatory iodisation of household salt in Poland has led to a sustainable optimisation of iodine status in the general population. However, it has failed to assure adequate iodine nutrition during pregnancy and lactation.

Breast Milk Iodine Concentration Is Associated with Infant Growth, Independent of Maternal Weight

In breastfed infants, human milk provides the primary source of iodine to meet demands during this vulnerable period of growth and development. Iodine is a key micronutrient that plays an essential role in hormone synthesis. Despite the importance of iodine, there is limited understanding of the maternal factors that influence milk iodine content and how milk iodine intake during infancy is related to postnatal growth. We examined breast milk samples from near 2 weeks and 2 months post-partum in a mother-infant dyad cohort of mothers with pre-pregnancy weight status defined by body mass index (BMI). Normal (NW, BMI < 25.0 kg/m2) is compared to overweight/obesity (OW/OB, BMI ≥ 25.0 kg/m2). The milk iodine concentration was determined by inductively coupled plasma mass spectrometry. We evaluated the associations between iodine content at 2 weeks and infant anthropometrics over the first year of life using multivariable linear mixed modeling. Iodine concentrations generally decreased from 2 weeks to 2 months. We observed no significant difference in iodine based on maternal weight. A higher iodine concentration at 2 weeks was associated with a larger increase in infant weight-for-age and weight-for-length Z-score change per month from 2 weeks to 1 year. This pilot study shows that early iodine intake may influence infant growth trajectory independent of maternal pre-pregnancy weight status.

The effect of iodine deficiency during pregnancy on child development

It is well known that severe iodine deficiency during pregnancy may cause impaired brain development in the child, with effects on cognitive and motor function, hearing and speech. Whether mild-to-moderate deficiency also affects neurological development is less well known, but in the past decade a number of observational studies have been conducted to answer this question and these studies are reviewed in this article. The picture is now emerging that even mild-to-moderate iodine deficiency during pregnancy may be associated with subtle impairments in cognition and school performance, although the evidence from randomised controlled trials is still lacking. As global efforts to eradicate iodine deficiency in populations continue, it is more likely that mild-to-moderate, rather than severe, iodine deficiency will be the issue of concern in pregnancy, and therefore further research in regions of mild-to-moderate deficiency is required to strengthen the research base and to inform public-health policy.

First national iodine survey in Madagascar demonstrates iodine deficiency

Universal salt iodization (USI) was adopted in Madagascar in 1995 within the framework of a worldwide policy to eliminate iodine deficiency disorders. Despite early USI adoption, there are no representative data on the iodine status of the Malagasy population. The aims of this study were to determine the iodine status of the Malagasy population and to assess the use of adequately iodized salt among households. We randomly sampled women of reproductive age (WRA) using a national, two-stage, stratified cross-sectional survey in 2014. Casual urine from WRA and salt samples from the household containing WRA were collected to measure urinary iodine concentration (UIC) and to assess household salt iodine content. Data from 1,721 WRA in 1,128 households were collected and analysed. The national median UIC was 46 μg L^-1 (interquartile range [IQR]: 13-98 μg L^-1 ), indicating a moderate iodine deficiency. The median UIC was 53 μg L^-1 (IQR: 9-89 μg L^-1 ) in pregnant women and 46 μg L^-1 (IQR: 13-98 μg L^-1 ) in non-pregnant women. The national median iodine concentration of household salt was 10 mg kg^-1 (IQR: 6.3-15.8 mg kg^-1 ) and 26.2% (95% CI [22.1, 31.0]) of households containing WRA used adequately iodized salt (≥15 mg kg^-1 ). Women living in households with adequately iodized salt had higher median UIC (72 vs. 50 μg L^-1 ). Iodine status was significantly lower among women from low socio-economic households. Madagascar's USI program needs to be revitalized. Implementing strategies to provide adequately iodized salt and enhancing iodized salt legislation to prevent severe complications resulting from iodine deficiency in the Malagasy population are essential.

Availability of adequately iodized salt at household level in Dessie and Combolcha Towns, South Wollo, Ethiopia

Background

Iodine deficiency disorder is the leading cause of mental retardation and poor economic performance in developing countries. Worldwide, universal salt iodization has been implemented to eliminate iodine deficiency. However, the adequacy of iodine in salts needs close monitoring to meet its intended goal and this study was aimed at investigating the adequacy of iodine in dietary salt at household level in Dessie and Combolcha Towns.

Methods

A community-based cross-sectional study was employed at household level in Dessie and Combolcha towns from January to February, 2017. Data were collected from 753 households using systematic sampling technique. The adequacy of iodine in salt was analyzed using rapid testing kit. Socio-demographic and economic, dietary sources, labeling, packaging, storage and cooking methods of household’s characteristics were collected via questionnaire developed using open data kit tool and STATA version 12 was used for further statistical analysis. Ordinal Logistic regression was performed to assess associations between explanatory variables and the response variable.

Results

Nearly one-thrid (31.2%) of the households used inadequate iodized salt, which was below the World Health Organization recommendation level (≥15 ppm at the household level). Most of the respondents from Combolcha town (64.6%) were affected by inadequate use of iodized salt as compared to Dessie Town residents (22.2%). Being Dessie resident (OR = 2.53; 95% CI: 1.31–4.90), households with better socioeconomic status (OR = 2.54; 95% CI:1.10–5.87), site of labeling and packing (salt from open market (OR = 0.10; 95% CI: 0.04–0.23) and no exposure to sunlight (OR = 2.54; 95% CI:1.31–4.91) were the predictors of adequacy of iodized salt at household level.

Conclusions

Availability of adequately iodized salt at the household level in the study area was low. There should be regular quality control and regulatory enforcement of salt iodization at production, labeling and packaging sites of small scale industries and at household level.

Effects of Iodized Salt and Iodine Supplements on Prenatal and Postnatal Growth: A Systematic Review

Hypothyroidism due to iodine deficiency can impair physical development, most visibly in the marked stunting of myxedematous cretinism caused by severe in utero iodine deficiency. Whether iodine repletion improves growth in noncretinous children is uncertain. Therefore, the aim of our systematic review was to assess the effects of iodine fortification or supplementation on prenatal and postnatal growth outcomes in noncretinous children. Following Cochrane methods and PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) reporting guidelines, we searched 10 databases including 2 Chinese databases (latest search February 2017). We included randomized and nonrandomized controlled trials (RCTs; non-RCTs), controlled before-after (CBA) studies, and interrupted time-series studies in pregnant women and children (≤18 y), which compared the effects of iodine (any form, dose, regimen) to placebo, noniodized salt, or no intervention on prenatal and postnatal growth outcomes. We calculated mean differences with 95% CIs, performed random-effects meta-analyses, and assessed the quality of evidence with the use of GRADE (Grading of Recommendations Assessment, Development and Evaluation). We included 18 studies (13 RCTs, 4 non-RCTs, 1 CBA) (n = 5729). Iodine supplementation of severely iodine-deficient pregnant women increased mean birthweight [mean difference (MD): 200 g; 95% CI: 183, 217 g; n = 635; 2 non-RCTs] compared to controls, but the quality of this evidence was assessed as very low. Iodine repletion across the other groups showed no effects on primary growth outcomes (quality of evidence mostly low and very low). Meta-analyses showed a positive effect in moderate-to-mildly iodine-deficient schoolchildren on insulin-like growth factor-1 (MD: 38.48 ng/mL; 95% CI: 6.19, 70.76 ng/mL; n = 498; 2 RCTs, low-quality evidence) and insulin-like growth factor binding protein-3 (MD: 0.46 μg/mL; 95% CI: 0.25, 0.66 μg/mL; n = 498; 2 RCTs, low-quality evidence). In conclusion, we identified few well-designed trials examining the effects of iodine repletion on growth. We are uncertain whether prenatal iodine repletion increases infant growth. Postnatal iodine repletion may improve growth factors but has no clear effects on somatic growth. Our systematic review was registered with PROSPERO as CRD42014012940.

Introduction of iodised salt benefits infants' mental development in a community-based cluster-randomised effectiveness trial in Ethiopia

The effectiveness of salt iodisation in improving the mental development of young children has not been assessed. We implemented a community-based cluster-randomised effectiveness trial in sixty randomly selected districts in the Amhara region of Ethiopia. We randomly allocated each district to treatment and randomly selected one of its villages. In parallel to national salt iodisation efforts, iodised salt was brought early into the markets of the thirty intervention villages before it became widely available in the thirty control villages 4-6 months later. The primary outcome was children's mental development scores on the Bayley Scales. This was an intention-to-treat analysis using mixed linear models adjusted for covariates and clusters. The trial was registered at ClinicalTrials.gov, NCT013496. We assessed 1835 infants aged 5-11 months at baseline. The same children (85 % of the sample) were re-assessed at 20-29 months when all villages had iodised salt. At endline, urinary iodine concentration was higher in children in the intervention group compared with those in the control group (median 228·0 v. 155·1 µg/l, P=0·001). The intervention group had higher scores compared with the control group on the Bayley composite score (raw scores:130·60 v. 128·51; standardised scores: 27·8 v. 26·9; d=0·13; 95 % CI 0·02, 0·23) and three of the four subscales: cognitive (53·27 v. 52·54, d=0·13; 95 % CI 0·03, 0·23), receptive language (20·71 v. 20·18, d=0·13; 95 % CI 0·03, 0·24) and fine motor (35·45 v. 34·94, d=0·15; 95 % CI 0·04, 0·25). The introduction of iodised salt contributes to children's higher urinary iodine concentration and mental development.

Reduced Educational Outcomes Persist into Adolescence Following Mild Iodine Deficiency in Utero, Despite Adequacy in Childhood: 15-Year Follow-Up of the Gestational Iodine Cohort Investigating Auditory Processing Speed and Working Memory

There is increasing evidence that even mild gestational iodine deficiency (GID) results in adverse neurocognitive impacts on offspring. It's unclear, however, if these persist long-term and whether they can be ameliorated by iodine sufficiency in childhood. We followed a unique cohort (Gestational Iodine Cohort, n = 266) where gestation occurred during a period of mild population iodine deficiency, with children subsequently growing-up in an iodine replete environment. We investigated whether associations between mild GID and reductions in literacy outcomes, observed at age 9-years, persisted into adolescence. Comparisons were made between offspring of mothers with gestational urinary iodine concentrations (UICs) ≥ 150 μg/L and < 150 μg/L. Educational outcomes were measured using Australian National Assessment Program-Literacy and Numeracy (NAPLAN) tests. Children whose mothers had UICs < 150 μg/L exhibited persistent reductions in spelling from Year 3 (10%, -41.4 points (95% Confidence Interval -65.1 to -17.6, p = 0.001)) to Year 9 (5.6%, -31.6 (-57.0 to -6.2, p = 0.015)) compared to children whose mothers had UICs ≥ 150 μg/L. Associations remained after adjustment for biological factors, socioeconomic status and adolescent UIC. Results support the hypothesis that mild GID may impact working memory and auditory processing speed. The findings have important public health implications for management of iodine nutrition in pregnancy.

Associations between thyroid dysfunction and developmental status in children with excessive iodine status

Background and objective

Adequate iodine status and normal thyroid hormone synthesis are important for optimal child development. In this study, we explored whether young children’s developmental status is associated with thyroid dysfunction in an area of chronic excessive iodine exposure.

Methods

We included 298 children between 18 and 48 months of age residing in Algerian refugee camps. Early child development was measured using the Ages and Stages Questionnaires, third edition (ASQ-3), consisting of five domains: Communication, Gross Motor, Fine Motor, Problem Solving and Personal-Social. Due to poor discriminatory ability in the Gross Motor domain, the total ASQ-3 scores were calculated both including and excluding this domain. Urinary iodine concentration (UIC), thyroid hormones (TSH, FT3 and FT4), thyroid antibodies and serum thyroglobulin (Tg) were measured.

Results

The median UIC was 451.6 μg/L, and approximately 72% of the children had a UIC above 300 μg/L. Furthermore, 14% had thyroid disturbances, of whom 10% had TSH outside the reference range. Children with thyroid disturbances and TSH outside the reference ranges had lower odds of being among the 66% highest total ASQ scores, with adjusted odds ratios (95% CI) of 0.46 (0.23, 0.93) and 0.42 (0.19, 0.94), respectively.

Conclusion

We found an association between thyroid dysfunction and poorer developmental status among children with excessive iodine intake. The high iodine intake may have caused the thyroid dysfunction and hence the delayed developmental status; however, other influential factors cannot be excluded. Optimal child development is important for a sustainable future. With iodine excess being an increasing problem globally, this subject should be further explored.

A Randomized, Double-Blind Study Assessing Changes in Cognitive Function in Indian School Children Receiving a Combination of Bacopa monnieri and Micronutrient Supplementation vs. Placebo

Several studies have indicated a chronic cognitive enhancing effect of Bacopa monnieri across different ages and cognitive impairment associated with vitamin and mineral deficiencies in children. Therefore, we investigated the effects of 4-month supplementation with a combination of B. monnieri extract and multiple micronutrients on cognitive functions in Indian school children aged 7–12 years. This was a randomized, double-blind, parallel design, single-center study in which 300 children were randomized to receive a beverage either fortified with B. monnieri and multiple micronutrients (“fortified”) or a non-fortified isocaloric equivalent (“control”) twice-daily for 4 months. Cognitive function was assessed by the Cambridge Neuropsychological Automated Test Battery (CANTAB) administered at baseline, Day 60 and Day 121. The primary endpoint was change in short-term memory (working memory) from baseline in subjects receiving “fortified” vs. “control” beverages after 4 months. Secondary endpoints included sustained attention, episodic memory, and executive function. The “fortified” beverage did not significantly improve short-term memory or any of the secondary outcomes tested relative to the “control” beverage. However, the spatial working memory “strategy” score showed significant improvement on Day 60 (difference between groups in change from baseline: −0.55; p < 0.05), but not on Day 121 due to the active intervention. Study products were well-tolerated. Reasons for these unexpected findings are discussed.

Variation in iodine food composition data has a major impact on estimates of iodine intake in young children

BACKGROUND/OBJECTIVES

The reliability of an estimate of iodine intake is largely dependent on the quality of the food composition data. We aimed to assess the impact of variations in food composition data for iodine and season on the estimates of iodine intake in young children.

SUBJECTS/METHODS

Cross-sectional dietary intake study of Irish 2-year-olds participating in the Cork BASELINE Birth Cohort Study (n=468; 30% of the cohort at the 2-year follow-up) were used to assess the impact of variation in iodine food composition data on estimates of iodine intake, dietary adequacy and risk of exceeding the tolerable upper intake level (UL).

RESULTS

Mean (SD) iodine intakes calculated using UK (147 (71)) and Irish (177 (93)) food composition data were significantly different (P < 0.001) (mean difference (95% confidence interval) = 30 (26-33) µg/day) and largely adequate (7-14% below the estimated average requirement). Intakes at the 95th percentile were 138% and 173% of the UL using UK and Irish food composition data, respectively, of which milk accounted for 106% and 150% of the UL. This translated into 22% and 35% of toddlers exceeding the UL, using UK and Irish composition data, respectively. The mean (SD) daily intake of cow's milk among the 91% of consumers was 309 (208) ml. Intakes of cow's milk at the 75th and 95th percentiles were 452 and 706 ml, respectively. Using Irish composition data for iodine in cows' milk, a daily intake of 450 ml could result in a toddler exceeding the UL from milk alone.

CONCLUSIONS

Variability in food composition has a large impact on assessments of iodine intake, particularly among young children for whom milk contributes a large proportion of their daily nutrient intake. Although this is unlikely to result in long-term adverse effects, our study highlights the need for development of valid biomarkers of individual iodine status.

Nutrition (Micronutrients) in Child Growth and Development: A Systematic Review on Current Evidence, Recommendations and Opportunities for Further Research

OBJECTIVE

An important aspect of malnutrition is deficiency of different micronutrients during pregnancy or early childhood. We systematically reviewed the role of nutrition in child growth (weight or height gain) and development.

METHODS

A comprehensive literature search was done on PubMed/Cochrane Library browsing through 38,795 abstracts until December 31, 2016 to select systematic reviews/meta-analyses and individual randomized controlled trials (RCTs) of micronutrient supplementation.

RESULTS

Micronutrients studied included iron, iodine, folate, zinc, calcium, magnesium, selenium, vitamin D, vitamin A, vitamin B complex, and multiple micronutrients. We summarize evidence with details and results of RCTs, highlight strengths/weaknesses, and critically interpret findings. Effects of breastfeeding-promotion, food-supplementation (complementary and school feeding), conditional-cash-transfers, and integrated nutrition/psychosocial interventions are discussed.

CONCLUSION

Based on this evidence we make policy and programmatic recommendations for supplementation to mothers and children at high-risk of deficiency.

A Paleolithic-type diet results in iodine deficiency: a 2-year randomized trial in postmenopausal obese women

BACKGROUND/OBJECTIVES

Different diets are used for weight loss. A Paleolithic-type diet (PD) has beneficial metabolic effects, but two of the largest iodine sources, table salt and dairy products, are excluded. The objectives of this study were to compare 24-h urinary iodine concentration (24-UIC) in subjects on PD with 24-UIC in subjects on a diet according to the Nordic Nutrition Recommendations (NNR) and to study if PD results in a higher risk of developing iodine deficiency (ID), than NNR diet.

SUBJECTS/METHODS

A 2-year prospective randomized trial in a tertiary referral center where healthy postmenopausal overweight or obese women were randomized to either PD (n=35) or NNR diet (n=35). Dietary iodine intake, 24-UIC, 24-h urinary iodine excretion (24-UIE), free thyroxin (FT4), free triiodothyronine (FT3) and thyrotropin (TSH) were measured at baseline, 6 and 24 months. Completeness of urine sampling was monitored by para-aminobenzoic acid and salt intake by urinary sodium.

RESULTS

At baseline, median 24-UIC (71.0 μg/l) and 24-UIE (134.0 μg/d) were similar in the PD and NNR groups. After 6 months, 24-UIC had decreased to 36.0 μg/l (P=0.001) and 24-UIE to 77.0 μg/d (P=0.001) in the PD group; in the NNR group, levels were unaltered. FT4, TSH and FT3 were similar in both groups, except for FT3 at 6 months being lower in PD than in NNR group.

CONCLUSIONS

A PD results in a higher risk of developing ID, than a diet according to the NNR. Therefore, we suggest iodine supplementation should be considered when on a PD.

Iodine Intakes of Victorian Schoolchildren Measured Using 24-h Urinary Iodine Excretion

Mandatory fortification of bread with iodized salt was introduced in Australia in 2009, and studies using spot urine collections conducted post fortification indicate that Australian schoolchildren are now replete. However an accurate estimate of daily iodine intake utilizing 24-h urinary iodine excretion (UIE μg/day) has not been reported and compared to the estimated average requirement (EAR). This study aimed to assess daily total iodine intake and status of a sample of primary schoolchildren using 24-h urine samples. Victorian primary school children provided 24-h urine samples between 2011 and 2013, from which urinary iodine concentration (UIC, μg/L) and total iodine excretion (UIE, μg/day) as an estimate of intake was determined. Valid 24-h urine samples were provided by 650 children, mean (SD) age 9.3 (1.8) years (n = 359 boys). The mean UIE of 4–8 and 9–13 year olds was 94 (48) and 111 (57) μg/24-h, respectively, with 29% and 26% having a UIE below the age-specific EAR. The median (IQR) UIC was 124 (83,172) μg/L, with 36% of participants having a UIC < 100 μg/L. This convenience sample of Victorian schoolchildren were found to be iodine replete, based on UIC and estimated iodine intakes derived from 24-h urine collections, confirming the findings of the Australian Health Survey.

First Israeli National Iodine Survey Demonstrates Iodine Deficiency Among School-Aged Children and Pregnant Women

BACKGROUND

National data on iodine status in Israel are lacking. Reliance on iodine-depleted desalinated water, the absence of a salt iodization program, and reports of increased use of thyroid medication in Israel suggest that the population's iodine intake is likely inadequate. The aims of this study were therefore to determine the iodine status of Israeli school-age children (SAC) and pregnant women (PW) in a nationally representative sample obtained by a novel approach of using pre-discard urinalysis samples collected from a centralized national laboratory.

METHODS

Spot urine samples from 1023 SAC and 1074 PW, representing all regions and major sectors in Israel, were collected during 2016 at the Maccabi Healthcare Services central laboratory. Urinary iodine concentration (UIC) was measured, and the results were analyzed by trimester, sex, region, and sector.

RESULTS

SAC were iodine deficient, with a median (interquartile range [IQR]) UIC of 83 μg/L (52-127 μg/L); 62% of SAC UICs were below the World Health Organization adequacy range for SAC (100-199 μg/L). PW were also iodine deficient, with a median (IQR) UIC of 61 μg/L (36-97 μg/L); 85% of PW UICs were below the adequacy range for PW (150-249 μg/L). For both SAC and PW, the median UIC was below the World Health Organization's adequacy range across all sectors, sexes, and districts. Among SAC, the median (IQR) UIC was lower among females (75 μg/L; 48-119 μg/L) than males (92 μg/L; 59-133 μg/L; p < 0.05). Median UIC values of PW correlated significantly with the median UIC for SAC by sub-district (R² = 0.3, p < 0.05).

CONCLUSIONS

Urine sampling via a centralized national laboratory was efficient and cost-saving. Iodine deficiency in Israeli SAC and PW is a serious public-health concern. A national program of salt iodization and iodine supplementation of PW should be urgently considered.

Iodine Status and Iodised Salt Consumption in Portuguese School-Aged Children: The Iogeneration Study

The World Health Organization promotes salt iodisation to control iodine deficiency. In Portugal, the use of iodised salt in school canteens has been mandatory since 2013. The present study aimed to evaluate iodine status in school-aged children (6-12 years) and to monitor the use of iodised salt in school canteens. A total of 2018 participants were randomly selected to participate in a cross-sectional survey in northern Portugal. Children's urine and salt samples from households and school canteens were collected. A lifestyle questionnaire was completed by parents to assess children's eating frequency of iodine food sources. Urinary iodine concentration (UIC) was measured by inductively coupled plasma-mass spectrometry. The median UIC was 129 µg/L which indicates the adequacy of iodine status and 32% of the children had UIC < 100 µg/L. No school canteen implemented the iodised salt policy and only 2% of the households were using iodised salt. Lower consumption of milk, but not fish, was associated with a higher risk of iodine deficiency. Estimation of sodium intake from spot urine samples could be an opportunity for adequate monitoring of population means. Implementation of iodine deficiency control policies should include a monitoring program aligned with the commitment of reducing the population salt intake.

The effect of daily zinc and/or multivitamin supplements on early childhood development in Tanzania: results from a randomized controlled trial

Impaired childhood development has lifelong consequences for educational attainment and wage-earning potential. Micronutrient supplements have the potential to improve development. The objective of this study was to determine the effect of daily zinc and/or multivitamin (vitamins C, E and B-complex) supplements on development among Tanzanian infants. In this randomized, 2 × 2 factorial, double-blind trial, 2400 infants were randomized to zinc (Zn), multivitamins (MV), zinc and multivitamins (Zn + MV) or placebo at 6 weeks of age. At approximately 15 months, a sub-sample of 247 children underwent developmental assessment using the cognitive, language (receptive and expressive) and motor (fine and gross) scales of the Bayley Scales of Infant and Toddler Development Third Edition (BSID-III). Mean BSID-III scores were compared using univariate and multivariate linear regression models adjusted for child's sex, post-conceptual age and test administrator. Logistic regressions were used to assess odds of low developmental scores. We did not detect a significant difference in mean BSID-III scores in any of the five domains in univariate or multivariate models comparing each of the four treatment groups. We also did not detect a significant difference in mean BSID-III scores when comparing children who received zinc supplements versus those who did not, or in comparisons of children who received multivitamin supplements versus those who did not. There was no significant difference in odds of a low BSID-III score in any of the five domains in treatment arms either. Because neither daily zinc nor multivitamin (vitamins B-complex, C and E) supplementation led to improvements in any of the developmental domains assessed using the BSID-III, we recommend pursuing alternative interventions to promote early childhood development in vulnerable populations. © 2016 John Wiley & Sons Ltd.

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).

Evolution of Sex Differences in Trait- and Age-Specific Vulnerabilities

Traits that facilitate competition for reproductive resources or that influence mate choice generally have a heightened sensitivity to stressors. They have evolved to signal resilience to infectious disease and nutritional and social stressors, and they are compromised by exposure to man-made toxins. Although these traits can differ from one species or sex to the next, an understanding of the dynamics of competition and choice can in theory be used to generate a priori predictions about sex-, age-, and trait-specific vulnerabilities for any sexually reproducing species. I provide a review of these dynamics and illustrate associated vulnerabilities in nonhuman species. The age- and sex-specific vulnerability of such traits is then illustrated for stressor-related disruptions of boys’ and girls’ physical growth and play behavior, as well as for aspects of boys’ and girls’ and men’s and women’s personality, language, and spatial abilities. There is much that remains to be determined, but enough is now known to reframe trait sensitivity in ways that will allow scientists and practitioners to better identify and understand vulnerable human traits, and eventually ameliorate or prevent their expression.

A multi-centre pilot study of iodine status in UK schoolchildren, aged 8-10 years

PURPOSE

Iodine, as an essential constituent of thyroid hormones, is required for brain development. Iodine status is low in some UK population groups, notably in teenage girls, women of childbearing age and pregnant women. We aimed to assess iodine status of UK schoolchildren as there are no data on children below 14 years of age.

METHODS

Children (boys and girls) aged 8-10 years were recruited to a cross-sectional study from schools in three areas of the UK (Omagh, Northern Ireland; Glasgow, Scotland, and Guildford, South-East England). Spot urine samples, for measurement of urinary iodine concentration, were collected in the winter months (November 2012 to March 2013) and in the summer, in Omagh only (September 2013). A food frequency questionnaire was completed.

RESULTS

A total of 168 schoolchildren provided 165 urine samples. The median urinary iodine concentration was 161 µg/L in winter samples (n = 134) and 127 µg/L in summer samples (n = 31). The median urinary iodine concentration for the whole group was 144 µg/L, weighted to account for the unequal proportion of samples from the two seasons. The children are classified as iodine-sufficient by WHO criteria (100-199 µg/L), even in the summer. Milk intake was positively associated with iodine status.

CONCLUSIONS

This pilot study suggests that iodine deficiency is unlikely to be a problem in UK children aged 8-10 years. This could be a result of higher intake of milk, the principal UK dietary iodine source, in this age group than in teenagers and adults. Further assessment of iodine status in a representative sample of UK schoolchildren is required.

Should urinary iodine concentrations of school-aged children continue to be used as proxy for different populations? Analysis of data from Chinese national surveys

I deficiency is a worldwide public health problem. Median urinary I concentration in school-aged children has been used globally as a proxy for all populations. This study aims to determine whether median urinary I concentration of school-aged children is an appropriate indicator of I nutritional status in different adult populations. This is a secondary data analysis of two national I Deficiency Disorder surveys (2011, 2014) and two regional surveys (in coastal areas, 2009, and in high-risk areas, 2009-2014). Population groups included in these surveys were school-aged children (8-10 years), pregnant women, lactating women, women of childbearing age and adults (men and women, 18-45 years). All participants were self-reported healthy without history of thyroid diseases or were not using thyroid medicines. The median urinary I concentration of school-aged children was matched with that of the other population at the county level. The matched populations had similar iodised salt supply, food and water I, food composition and I content in salt. Weak or moderate correlation of median urinary I concentrations was observed between school-aged children and pregnant women and between children and lactating women. However, the agreement was stronger between children and women of childbearing age and between children and adult men and women. The results could be affected by cut-off values, data aggregation level and sample size. Using median urinary I concentration of school-aged children tends to overestimate that of pregnant women and lactating women. Median urinary I concentration of school-aged children can be used for assessing I nutrition in the adult population.

Iodine Nutritional Status in Schoolchildren from Public Schools in Brazil: A Cross-Sectional Study Exposes Association with Socioeconomic Factors and Food Insecurity

INTRODUCTION

National programs of salt iodization were implemented in Brazil to combat iodine deficiency (ID) in children of school age. Currently, there are limited data in Brazil on those still vulnerable to this deficiency and the state of nutritional iodine status in the northeast region of Brazil, where children are vulnerable to malnutrition.

OBJECTIVE

The aim of this study was to analyze the iodine nutritional status, household food insecurity, socioeconomic and demographic characteristics among schoolchildren from the public school system living in state the state of Bahia, Brazil.

METHODS

A cross-sectional study was conducted on 1419 schoolchildren in Bahia between the ages of 6 and 14 years old. Anthropometric parameters, urinary iodine concentrations (UIC), and thyrotropin (TSH) measurements were evaluated from blood spots on filter paper.

RESULTS

The mean UIC was 206.4 ± 80.5 μg/L, with a median of 221.6 μg/L, indicating sufficient iodine intake in the region. Low urinary iodide concentration (<100 μg/L) was detected in 12.3% of the schoolchildren (n = 174), with 6.2% with mild (<100 μg/L), 3.0% with moderate (20-49 μg/L), and 3.1% with severe ID (<20 μg/L). Moreover, 9.4% (n = 134) had a urinary iodide concentration of >300 μg/L, indicating the coexistence of excessive iodine intake (EII). The mean TSH was 1.0 ± 0.6 mIU/L. The body mass index category "overweight/obesity" was a protective factor against EII (odds ratio [OR] = 0.64 [confidence interval (CI) 0.4-1.0]; p = 0.07). Urban areas (73%) had a mean UIC of 213.1 ± 80 μg/L compared with 176.8 ± 76.1 μg/L in rural areas. The risk for EII increased in children living in a house with more than six people (OR = 1.62 [CI 0.9-2.6]; p < 0.05) and water consumption from shallow wells (OR = 1.70 [CI 0.9-3.1]; p = 0.09). The risk of ID was increased by 70% in schoolchildren who had moderate or severe food insecurity (OR = 1.70 [CI 0.9-3.0]; p > 0.05).

CONCLUSION

A significant proportion of schoolchildren still have ID or EII in the northeast region of Brazil, emphasizing the importance of committed public policies to address this problem. Socioeconomic factors and the lack of education about nutritional importance of iodine were important influencing factors in the presence of ID in schoolchildren.