Effect of perinatal consumption of low-calorie sweetener on maternal health: A systematic review and meta-analysis.

BACKGROUND AND AIMS: Evidence regarding perinatal low-calorie (or artificial) sweetener (LCS) consumption and its effect on maternal health outcomes is limited and inconclusive. The primary outcomes of our systematic review and meta-analysis were the effect of preconception and pregnancy LCS exposure on reproductive and pregnancy outcomes. Secondary outcomes included long-term maternal health. METHODS: A systematic search of electronic databases, including PubMed, Embase, CINAHL, the Cochrane Library, Scopus, Web of Science, PsycINFO, ProQuest Health and Medical, ClinicalTrials.gov and Google Scholar, was conducted up to 20 November 2023. Primary studies, including clinical trials, cohort studies, case-control studies, which reported any LCS consumption during perinatal period and pregnancy and maternal health outcomes were eligible. A random effects model with restricted maximum likelihood estimation was used for the meta-analysis. We appraised the quality of the included studies using the National Institute of Health study quality appraisal tool and the overall quality of evidence using the Grading of Recommendations Assessment, Development, and Evaluation tool. RESULTS: A total of 19 eligible studies with 203,706 participants were included. LCS consumption during pregnancy was associated with 11% increased risk of preterm birth (RR = 1.11, 95% CI: 1.07-1.16, I2 = 0.01%) and 42% increased risk of gestational diabetes (RR = 1.42, 95% CI: 0.98-2.04, I2 = 67.60%) compared with no consumption, however, the effect size for gestational diabetes was not precise as the 95% CI indicated that the effect estimate could range from 2% lower risk to 204% (or 2.04 times) higher risk. We found no association between LCS consumption during pregnancy and gestational weight gain (standardized mean difference (SMD) = 0.04; 95% CI: -0.17 - 0.24, I2 = 41.31%) or gestational age at birth (SMD = 0.00; 95% CI: -0.13 - 0.14, I2 = 80.13%). The effect of LCS consumption on reproductive treatment outcomes were inconsistent. CONCLUSIONS: Based on the evidence available, LCS consumption in pregnancy was associated with increased risk of preterm birth and gestational diabetes. Robust research, such as well-designed randomized trials and large prospective cohort studies, is required to confirm the causal effect of LCS consumption during perinatal period on adverse maternal health outcomes.

Patterns and Predictors of Low-Calorie Sweetener Consumption during Pregnancy: Findings from a National Survey.

Recently, the World Health Organization recommended avoiding low-calorie sweeteners (LCS) during pregnancy due to concerns that it may be linked to adverse pregnancy outcomes and offspring wellbeing. This study examined the patterns and predictors of LCS consumption among pregnant women in Australia. A survey was conducted among 422 pregnant women aged 18-50 years. Sociodemographic, lifestyle, dietary intake including LCS consumption, pregnancy-related characteristics, and awareness about the health effects of LCS were assessed. We used latent class analysis and multinomial logistic regression to identify LCS consumption patterns and predictors of consumption patterns, respectively. The mean (SD) age of the women was 30 (4.6) years. Three LCS consumption patterns were identified: infrequent or non-consumers representing 50% of the women, moderate consumers encompassing 40% of the women, and the remaining were habitual consumers. Over two-thirds (71%) of women were not aware of the potential adverse effects of LCS, and only a quarter of them were concerned about the possible adverse effects on their health and their offspring. Increasing age and living with a medical condition decreased the likelihood of moderate consumption by 7% and 55%, respectively. Frequent sugar-sweetened beverage consumption and gestational diabetes predicted habitual LCS consumption. This research suggested widespread LCS consumption among pregnant women in Australia, but lower awareness of its potential adverse health effects. Interventions to increase awareness of potential adverse effects are warranted.

Testing the Impact of Familiarity with Health Benefits Information on Dietary Supplement Choice in Pregnancy: An Online Choice Experiment.

To help meet the increased requirements for critical nutrients during and around pregnancy, supplementation with essential nutrients is recommended. This study aims to determine how the previous awareness of nutrient health benefits and/or the provision of this information influences the importance placed on nutrients (folate, iodine, omega-3 fatty acids, and vitamin D) when choosing between dietary supplement products for pregnancy. Discrete choice experiment data were collected as part of a cross-sectional online survey administered to 857 pregnant women living in Australia. Four segments of women were identified that differ in their preference criteria when choosing among dietary supplement products for pregnancy. When choosing between products, the reinforcement of perceived health benefits (i.e., showing information on health benefits to those already aware of the benefits) was most effective at increasing the importance of folate (in all segments) and iodine (in two segments, 63% of the sample). Neither prior awareness of health benefits alone nor information provided at the point-of-purchase without prior awareness were enough to increase the importance of folate. Our findings suggest a need for simultaneous strategies that (1) provide information on health benefits before purchase and (2) ensure that information on health benefits is available at the point-of-purchase.

Association Between Newborn Thyroid-Stimulating-Hormone Concentration and Neurodevelopment and Growth: a Systematic Review.

Iodine nutrition during pregnancy can affect newborn thyroid-stimulating-hormone concentration (TSH). Associations of newborn TSH with the neurodevelopment and growth of children are inconsistent. The aim of the study was to systematically review the literature on the associations between newborn TSH and childhood neurodevelopment and growth. Databases including PubMed, Scopus, CINAHL, Embase, PsycINFO, WHO, and Iodine Global Network were searched for eligible studies. Seventeen studies were included. Neurodevelopment was assessed using different tools in children aged 1-12 years of age. The associations between newborn TSH and cognitive development were negative in studies from iodine deficient populations, while a null association was found in studies from iodine sufficient populations. A null association between TSH and psychomotor development was observed regardless of iodine status of the study populations. There was no evidence of an association between newborn TSH and child anthropometry, but evidence of negative association was found between newborn TSH and birthweight. Although the associations between newborn TSH and neurodevelopment may differ based on the iodine status of populations, most of the included studies did not adjust for the key confounders and had a small sample size. Quality data-linkage studies that utilize newborn TSH data from newborn screening with adequate adjustment for potential confounders are warranted to better understand the relationship between newborn TSH and neurodevelopment and growth in children. CRD42020152878.

Effect of Selenium and Iodine on Oxidative Stress in the First Trimester Human Placenta Explants.

Imbalanced maternal micronutrient status, poor placentation, and oxidative stress are associated with greater risk of pregnancy complications, which impact mother and offspring health. As selenium, iodine, and copper are essential micronutrients with key roles in antioxidant systems, this study investigated their potential protective effects on placenta against oxidative stress. First trimester human placenta explants were treated with different concentrations of selenium (sodium selenite), iodine (potassium iodide), their combination or copper (copper (II) sulfate). The concentrations represented deficient, physiological, or super physiological levels. Oxidative stress was induced by menadione or antimycin. Placenta explants were collected, fixed, processed, and embedded for laser ablation inductively coupled plasma-mass spectrometry (LA ICP-MS) element imaging or immunohistochemical labelling. LA ICP-MS showed that placenta could uptake selenium and copper from the media. Sodium selenite and potassium iodide reduced DNA damage and apoptosis (p < 0.05). Following oxidative stress induction, a higher concentration of sodium selenite (1.6 µM) was needed to reduce DNA damage and apoptosis while both concentrations of potassium iodide (0.5 and 1 µM) were protective (p < 0.05). A high concentration of copper (40 µM) increased apoptosis and DNA damage but this effect was no longer significant after induction of oxidative stress. Micronutrients supplementation can increase their content within the placenta and an optimal maternal micronutrient level is essential for placenta health.

Associations between newborn thyroid-stimulating hormone concentration and neurodevelopment and growth of children at 18 months.

The study aimed to assess the associations between newborn thyroid-stimulating hormone (TSH) concentration, a marker of iodine nutrition in early life, and childhood neurodevelopment and growth using data collected from two pregnancy studies, one in a borderline iodine-deficient setting (DHA to Optimize Mother Infant Outcome (DOMInO) Study) and one in an iodine-sufficient setting (Pregnancy Iodine and Neurodevelopment in Kids (PINK) Study). TSH data were obtained from routine newborn screening. Neurodevelopment was assessed at 18 months using the Bayley Scales of Infant and Toddler Development, third edition (Bayley-III). Weight, height and head circumference were measured at 18 months. In total, 1467 children were included in the analysis. Comparing the highest with the lowest TSH quartile, the mean differences (MD) in the Bayley-III scores ranged from -2·0 (95 % CI -4·7, 0·7) to -2·2 (95 % CI -5·8, 1·3) points in DOMInO and 1·0 (95 % CI -1·6, 3·6) to 2·0 (95 % CI -0·4, 4·4) points in PINK in the cognitive, language and motor scales; the MD in the anthropometric z scores ranged from -0·01 (95 % CI -0·5, 0·5) to -0·5 (95 % CI -0·9, -0·1) in both studies. A 1 mIU/l increase in TSH was associated with -0·3 (95 % CI -0·9, 0·2) point and 0·2 (95 % CI -0·3, 0·7) point changes in the mean cognitive score in the DOMInO and PINK, respectively. A null association between TSH and growth was also observed in both studies. Longitudinal studies that utilise newborn TSH data and examine neurodevelopmental outcomes at later ages are warranted, as neurodevelopmental assessments in older children are more predictive of later achievement.

Effect of Iodine and Selenium on Proliferation, Viability, and Oxidative Stress in HTR-8/SVneo Placental Cells.

Adequate maternal micronutrition is vital for placental formation, fetal growth, and development. Oxidative stress adversely affects placental development and function and an association between deficient placental development, oxidative stress, and micronutrient deficiency has been observed. Selenium and iodine are two essential micronutrients with antioxidant properties. Epidemiological studies have shown that poor micronutrient status in pregnant women is associated with a higher incidence of pregnancy complications. The aim of this study was to determine how selenium, iodine, and their combination impact oxidative stress in placental trophoblast cells. HTR8/SVneo extravillous trophoblasts were supplemented with a concentration range of organic and inorganic selenium, potassium iodide, or their combination for 24 h. Oxidative stress was then induced by treating cells with menadione or H2O2 for 24 h. Cell viability and lipid peroxidation as the biomarker of oxidative stress were assessed at 48 h. Both menadione and H2O2 reduced cell viability and increased lipid peroxidation (P < 0.05). Greater cell viability was found in selenium-supplemented cells when compared with vehicle treated cells (P < 0.05). Selenium and iodine supplementation separately or together were associated with lower lipid peroxidation compared with vehicle control (P < 0.05). Supplementation with the combination of selenium and iodine resulted in a greater reduction in lipid peroxidation compared with selenium or iodine alone (P < 0.05). Oxidative stress negatively impacts trophoblast cell survival and cellular integrity. Selenium and iodine protect placental trophoblasts against oxidative stress. Further research is warranted to investigate the molecular mechanisms by which selenium and iodine act in the human placenta.

A comparison of nonlethal sampling methods for amphibian gut microbiome analyses.

Noninvasive sampling methods for studying intestinal microbiomes are widely applied in studies of endangered species and in those conducting temporal monitoring during manipulative experiments. Although existing studies show that noninvasive sampling methods among different taxa vary in their accuracy, no studies have yet been published comparing nonlethal sampling methods in adult amphibians. In this study, we compare microbiomes from two noninvasive sample types (faeces and cloacal swabs) to that of the large intestine in adult cane toads, Rhinella marina. We use 16S rRNA gene sequencing to investigate how microbial communities change along the digestive tract and which nonlethal sampling method better represents large intestinal microbiota. We found that cane toads' intestinal microbiota was dominated by Bacteroidetes, Proteobacteria and Firmicutes and, interestingly, we also saw a high proportion of Fusobacteria, which has previously been associated with marine species and changes in frog immunity. The large and small intestine of cane toads had a similar microbial composition, but the large intestine showed higher diversity. Our results indicate that cloacal swabs were more similar to large intestine samples than were faecal samples, and small intestine samples were significantly different from both nonlethal sample types. Our study provides valuable information for future investigations of the cane toad gut microbiome and validates the use of cloacal swabs as a nonlethal method to study changes in the large intestine microbiome. These data provide insights for future studies requiring nonlethal sampling of amphibian gut microbiota.

Comparison of iodine status pre- and post-mandatory iodine fortification of bread in South Australia: a population study using newborn thyroid-stimulating hormone concentration as a marker.

OBJECTIVE: The present study aimed to evaluate the effect of mandatory iodine fortification of bread on the iodine status of South Australian populations using newborn thyroid-stimulating hormone (TSH) concentration as a marker. DESIGN: The study used an interrupted time-series design. SETTING: TSH data collected between 2005 and 2016 (n 211 033) were extracted from the routine newborn screening programme in South Australia for analysis. Iodine deficiency is indicated when more than 3 % of newborns have TSH > 5 mIU/l. PARTICIPANTS: Newborns were classified into three groups: the pre-fortification group (those born before October 2009); the transition group (born between October 2009 and June 2010); and the post-fortification group (born after June 2010). RESULTS: The percentage of newborns with TSH > 5 mIU/l was 5·1, 6·2 and 4·6 % in the pre-fortification, transition and post-fortification groups, respectively. Based on a segmented regression model, newborns in the post-fortification period had a 10 % lower risk of having TSH > 5 mIU/l than newborns in the pre-fortification group (incidence rate ratio (IRR) = 0·90; 95 % CI 0·87, 0·94), while newborns in the transitional period had a 22 % higher risk of having TSH > 5 mIU/l compared with newborns in the pre-fortification period (IRR = 1·22; 95 % CI 1·13, 1·31). CONCLUSIONS: Using TSH as a marker, South Australia would be classified as mild iodine deficiency post-fortification in contrast to iodine sufficiency using median urinary iodine concentration as a population marker. Re-evaluation of the current TSH criteria to define iodine status in populations is warranted in this context.

Agreement between markers of population iodine status in classifying iodine status of populations: a systematic review.

BACKGROUND: Population iodine deficiency is indicated by >3% of the population with newborn thyroid-stimulating hormone (TSH) concentration >5 mIU/L, median urinary iodine concentration (MUIC) <100 µg/L, or >5% prevalence of goiter in school-age children. However, the agreement between these population markers has not been systematically investigated. OBJECTIVE: To assess the agreement between TSH, MUIC, and goiter as markers of population iodine status. METHODS: We performed a systematic search for studies published on PubMed, Scopus, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Embase, and PsycINFO up to 29 October, 2018. Studies assessing iodine status in the population using the TSH marker and either MUIC or goiter prevalence in school-age children were included. The agreement between markers in classifying iodine status of the population was assessed. The sensitivity and specificity of the TSH marker was determined against MUIC and goiter prevalence as the reference markers. RESULTS: Of 17,435 records identified by the search strategy, 57 eligible studies were included in the review. The agreement between markers in classifying the iodine status of populations into the same category was 65% for TSH and MUIC, and 83% for TSH and goiter prevalence. The TSH marker had a sensitivity of 0.75 and specificity of 0.53 when compared with MUIC, and 0.86 and 0.50 when compared with goiter prevalence. CONCLUSIONS: The TSH marker has a better agreement with goiter prevalence than MUIC when classifying the iodine status of populations. Re-evaluation of the current criteria for classifying the iodine status of populations using the TSH marker is warranted. This systematic review was registered at PROSPERO (http://www.crd.york.ac.uk/prospero/) as CRD42018091247.

Awareness of Listeriosis and Methylmercury toxicity public health recommendations and diet during pregnancy.

BACKGROUND: Awareness of Listeriosis and Methylmercury toxicity recommendations are associated with decreased intake of high-risk foods. Whether awareness of the recommendations affect dietary quality of pregnant women in Australian is unknown. AIM: To evaluate awareness of Listeriosis and Methylmercury toxicity recommendations during pregnancy and its impact on dietary quality. METHODS: Pregnant women (n=81) were recruited from antenatal clinics. Awareness of Listeriosis and Methylmercury toxicity recommendations and high-risk foods consumption were assessed via questionnaire at 10-23 weeks gestation. Diet quality was measured using the 2005 Healthy Eating Index using a validated food frequency questionnaire at 10-23 and 34-36 weeks gestation. FINDINGS: A higher proportion of women were aware of Methylmercury toxicity compared with Listeriosis recommendations (75.3 vs. 59.2%, p<0.001). The proportion of women who decreased or avoided consumption of certain high-risk Listeriosis foods were higher in those who were aware compared with those who were unaware of Listeriosis recommendations [raw fish (96.0 vs 69.2%, p=0.046), soft-serve ice cream (93.9 vs 58.3%, p=0.004) and alfalfa/bean sprouts (68.7 vs 28.5%, p=0.006)]. A large proportion of women (96.8%) met recommendations for limiting consumption of high Methylmercury fish. There was no difference in the change in dietary quality over pregnancy regardless of women's awareness of the recommendations. DISCUSSION AND CONCLUSIONS: Awareness of Listeriosis and Methylmercury toxicity recommendations has little impact on dietary quality of pregnant women in this small study. Further research in a large representative population of pregnant women is needed to confirm our findings and to optimise dietary quality during pregnancy.

Burden of disease attributable to suboptimal diet, metabolic risks and low physical activity in Ethiopia and comparison with Eastern sub-Saharan African countries, 1990-2015: findings from the Global Burden of Disease Study 2015.

BACKGROUND: Twelve of the 17 Sustainable Development Goals (SDGs) are related to malnutrition (both under- and overnutrition), other behavioral, and metabolic risk factors. However, comparative evidence on the impact of behavioral and metabolic risk factors on disease burden is limited in sub-Saharan Africa (SSA), including Ethiopia. Using data from the Global Burden of Disease (GBD) Study, we assessed mortality and disability-adjusted life years (DALYs) attributable to child and maternal undernutrition (CMU), dietary risks, metabolic risks and low physical activity for Ethiopia. The results were compared with 14 other Eastern SSA countries. METHODS: Databases from GBD 2015, that consist of data from 1990 to 2015, were used. A comparative risk assessment approach was utilized to estimate the burden of disease attributable to CMU, dietary risks, metabolic risks and low physical activity. Exposure levels of the risk factors were estimated using spatiotemporal Gaussian process regression (ST-GPR) and Bayesian meta-regression models. RESULTS: In 2015, there were 58,783 [95% uncertainty interval (UI): 43,653-76,020] or 8.9% [95% UI: 6.1-12.5] estimated all-cause deaths attributable to CMU, 66,269 [95% UI: 39,367-106,512] or 9.7% [95% UI: 7.4-12.3] to dietary risks, 105,057 [95% UI: 66,167-157,071] or 15.4% [95% UI: 12.8-17.6] to metabolic risks and 5808 [95% UI: 3449-9359] or 0.9% [95% UI: 0.6-1.1] to low physical activity in Ethiopia. While the age-adjusted proportion of all-cause mortality attributable to CMU decreased significantly between 1990 and 2015, it increased from 10.8% [95% UI: 8.8-13.3] to 14.5% [95% UI: 11.7-18.0] for dietary risks and from 17.0% [95% UI: 15.4-18.7] to 24.2% [95% UI: 22.2-26.1] for metabolic risks. In 2015, Ethiopia ranked among the top four countries (of 15 Eastern SSA countries) in terms of mortality and DALYs based on the age-standardized proportion of disease attributable to dietary and metabolic risks. CONCLUSIONS: In Ethiopia, while there was a decline in mortality and DALYs attributable to CMU over the last two and half decades, the burden attributable to dietary and metabolic risks have increased during the same period. Lifestyle and metabolic risks of NCDs require more attention by the primary health care system of the country.

Dietary patterns and obesity in preschool children in Australia: a cross-sectional study.

BACKGROUND AND OBJECTIVES: Dietary patterns have been linked to the risk of obesity in adults but little is known about such a link in young children. To examine the association between dietary patterns, nutrient intake and obesity in a representative population of preschool children in Australia. METHODS AND STUDY DESIGN: Dietary intake was assessed using a 3-day weighed food diary. Dietary patterns were identified by factor analysis. Children were classified as overweight or obesity if their BMI z-score was between the 85th-95th percentiles or was above the 95th percentile, respectively. RESULTS: Three dietary patterns were identified. The 'Traditional' pattern was characterised by grains, fruit, vegetables, and red meat. The 'Processed' pattern was characterised by processed meats, snack foods and confectionary. The 'Health conscious' pattern was characterised by eggs, fish, polyunsaturated margarines and low fat dairy products. The 'Traditional' pattern was positively associated with protein and zinc intake while the 'Processed' pattern was inversely associated. Both patterns were inversely associated with calcium intake. No associations were found between the 'Health conscious' pattern and macronutrients and key micronutrients intakes. The 'Traditional' pattern was positively associated with obesity but the association became non-significant after adjustment for energy and protein intake. No association was observed between the other two dietary patterns and weight status. CONCLUSIONS: In this cross-sectional study, dietary patterns were not associated with obesity. Longitudinal follow up will help to better understand the relationship between dietary patterns in early childhood and the risk of obesity later in life.

Iodine status five years after the mandatory salt iodization legislation indicates above requirement: a cross sectional study in Northwest Ethiopia.

BACKGROUND: Iodine deficiency is one of a major nutritional problem. The study aimed to assess the iodine status of populations in Dabat district using median urinary iodine concentration (UIC) in school-age children (6-12 years) and compared the results with goiter prevalence. METHODS: The study used a cross-sectional study design. The study was conducted in Dabat district, northwest Ethiopia in May 2016. Spot urine samples were used for the determination of UIC. Manual examination of the thyroid gland was performed to assess presence of goiter. The MBI international Rapid Test Kits (RTK) were used to determine the level of salt iodine content. Children aged 6-12 years were recruited from schools using a multistage stratified sampling. One-way Analysis of Variance (ANOVA) was used to compare mean of log-transformed UIC values among key variables. Significant was determined at P-value less than 0.05. RESULTS: A total of 358 school age children enrolled to the study. The mean age of children was 10.8((Standard Deviation (SD) = 1.45) years and 56.7% were males. The median UIC was 235 µg/l ((Inter Quartile Range (IQR): 161, 320]. Excessive iodine intake and inadequate iodine intake was observed on 29.1 and 8.7% of school aged children, respectfully. The coverage of iodized salt use in school-age children were 66.8%. The UIC was higher in urban children than rural counterparts and in those used adequately iodised salt than inadequately iodized salt (P < 0.05). Thirty-four percent of school-age children had a goiter. The prevalence of grade 1 and grade 2 goiter was 26.5 and 7.5%, respectively. There was a poor agreement between UIC and goiter (k = 0.1) in classifying iodine status of populations. CONCLUSIONS: The study population is classified as above requirements by median UIC in school-age children but severe iodine deficiency by goiter prevalence. Further research investigating the agreement between UIC and goiter prevalence in classifying iodine status of populations with various iodine status is warranted.

Comparison of breast-milk iodine concentration of lactating women in Australia pre and post mandatory iodine fortification.

OBJECTIVE: To compare the breast-milk iodine concentrations (BMIC) of lactating women before and after the mandatory iodine fortification of bread in Australia in 2009. DESIGN: Cross-sectional study. Breast milk samples were collected from two cohorts of women in South Australia within 7 d of delivery to determine BMIC. The percentage of samples with iodine concentration below 100 µg/l, a level considered adequate for breast-fed infants, was calculated. Sociodemographic information and intake of dietary supplements were obtained from all women. SETTING: The breast milk samples were collected between 2006 and 2007 in the pre-fortification cohort and between 2012 and 2013 in the post-fortification cohort. RESULTS: The median (interquartile range) BMIC was higher in the post-fortification samples compared with samples collected in the pre-fortification period (187 (130-276) v. 103 (73-156) µg/l; P<0·05). Overall, the percentage of women with BMIC <100 µg/l was lower in the post-fortification cohort than in the pre-fortification cohort (13 v. 49 %; P<0·01). The percentage of women with BMIC <100 µg/l in the post-fortification cohort was lower among women who took iodine supplements in pregnancy (12 v. 29 %; P<0·01). CONCLUSIONS: Mandatory iodine fortification of bread has resulted in an increase in the iodine content of breast milk in Australian women. However, iodine supplementation may still be required in some women post-iodine fortification to reach the level of BMIC that is considered adequate to meet the iodine requirement of full-term infants.

Validation of an optimized method for the determination of iodine in human breast milk by inductively coupled plasma mass spectrometry (ICPMS) after tetramethylammonium hydroxide extraction.

In this study a novel method to determine iodine concentrations in human breast milk was developed and validated. The iodine was analyzed by inductively coupled plasma mass spectrometry (ICPMS) following tetramethylammonium hydroxide (TMAH) extraction at 90°C in disposable polypropylene tubes. While similar approaches have been used previously, this method adopted a shorter extraction time (1h vs. 3h) and used antimony (Sb) as the internal standard, which exhibited greater stability in breast milk and milk powder matrices compared to tellurium (Te). Method validation included: defining iodine linearity up to 200µgL(-1); confirming recovery of iodine from NIST 1549 milk powder. A recovery of 94-98% was also achieved for the NIST 1549 milk powder and human breast milk samples spiked with sodium iodide and thyroxine (T4) solutions. The method quantitation limit (MQL) for human breast milk was 1.6µgL(-1). The intra-assay and inter-assay coefficient of variation for the breast milk samples and NIST powder were <1% and <3.5%, respectively. NIST 1549 milk powder, human breast milk samples and calibration standards spiked with the internal standard were all stable for at least 2.5 months after extraction. The results of the validation process confirmed that this newly developed method provides greater accuracy and precision in the assessment of iodine concentrations in human breast milk than previous methods and therefore offers a more reliable approach for assessing iodine concentrations in human breast milk.

Iodine status in pre-school children prior to mandatory iodine fortification in Australia.

The iodine status of children between the ages of 5 and 15 years has been routinely assessed in many countries, but few studies have examined iodine status in pre-school children. We conducted a cross-sectional study of pre-school children living in Adelaide, South Australia, between 2005 and 2007. Children 1-5 years old were identified using a unique sampling strategy to ensure that the study population was representative. A 3-day weighed diet record, a blood sample and a urine sample were obtained from each child. The median urinary iodine concentration (UIC) of the children (n = 279) was 129 µg L(-1), indicating iodine sufficiency (normal range: 100-199 µg L(-1)), but 35% of the children had a UIC < 100 µg L(-1). The median thyroglobulin concentration of children (n = 217) was 24 µg L(-1) and thyroglobulin concentration declined with increasing age (P = 0.024). The mean daily iodine intake was 76 µg. The intake of iodine was lower than expected and highlights difficulties in accurately assessing iodine intakes. Further studies are needed to monitor dietary changes and iodine status in this age group since the implementation of mandatory fortification of bread with iodised salt in Australia in 2009.