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

AbstractObjective: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.

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Iodine status of consumers of milk-alternative drinks v. cows’ milk: data from the UK National Diet and Nutrition Survey

British Journal Of Nutrition ◽

10.1017/s0007114520003876 ◽

2020 ◽

pp. 1-9

Author(s):

M. Dineva ◽

M. P. Rayman ◽

S. C. Bath

Keyword(s):

At Risk ◽

Iodine Deficiency ◽

Urinary Iodine ◽

Iodine Concentration ◽

Iodine Intake ◽

Urinary Iodine Concentration ◽

Nutrition Survey ◽

Iodine Status ◽

Adults And Children ◽

The Uk

Abstract Milk is the main source of iodine in the UK; however, the consumption and popularity of plant-based milk-alternative drinks are increasing. Consumers may be at risk of iodine deficiency as, unless fortified, milk alternatives have a low iodine concentration. We therefore aimed to compare the iodine intake and status of milk-alternative consumers with that of cows’ milk consumers. We used data from the UK National Diet and Nutrition Survey from years 7 to 9 (2014–2017; before a few manufacturers fortified their milk-alternative drinks with iodine). Data from 4-d food diaries were used to identify consumers of milk-alternative drinks and cows’ milk, along with the estimation of their iodine intake (µg/d) (available for n 3976 adults and children ≥1·5 years). Iodine status was based on urinary iodine concentration (UIC, µg/l) from spot-urine samples (available for n 2845 adults and children ≥4 years). Milk-alternative drinks were consumed by 4·6 % (n 185; n 88 consumed these drinks exclusively). Iodine intake was significantly lower in exclusive consumers of milk alternatives than cows’ milk consumers (94 v. 129 µg/d; P < 0·001). Exclusive consumers of milk alternatives also had a lower median UIC than cows’ milk consumers (79 v. 132 µg/l; P < 0·001) and were classified as iodine deficient by the WHO criterion (median UIC < 100 µg/l), whereas cows’ milk consumers were iodine sufficient. These data show that consumers of unfortified milk-alternative drinks are at risk of iodine deficiency. As a greater number of people consume milk-alternative drinks, it is important that these products are fortified appropriately to provide a similar iodine content to that of cows’ milk.

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Urinary iodine concentration: a biochemical parameter for assessing the iodine status

Mediscope ◽

10.3329/mediscope.v5i2.37146 ◽

2018 ◽

Vol 5 (2) ◽

pp. 30-35

Author(s):

GM Molla

Keyword(s):

Iodine Deficiency ◽

Urinary Iodine ◽

Iodine Concentration ◽

Iodine Intake ◽

Urinary Iodine Concentration ◽

Lactating Women ◽

Iodine Status ◽

Excessive Iodine ◽

Pregnancy And Lactation ◽

Neonates And Infants

Iodine is a micronutrient, which is essential for the synthesis of thyroid hormones. Thyroid hormones play a major role in the development of different functional components in different stages of life. The relationship between iodine intake level of a population and occurrences of thyroid disorders U-shaped with an increase from both low and high iodine intake. Iodine deficiency disorders (IDDs) are a major health problem worldwide in all age groups, but infants, school children, and pregnant and lactating women are vulnerable. During pregnancy and lactation, the fetus and infants are sensitive to maternal iodine intake. Even mild iodine deficiency may lead to irreversible brain damage during this period. A main cause of IDDs of neonates and infants is maternal iodine deficiency. Universal salt iodization strategy has been initiated by the World Health Organization and United Nation International Children Emergency Fund by the year 1993 for correction and prevention of iodine deficiency. Excessive iodine causes hypothyroidism, iodine-induced hyperthyroidism and autoimmune thyroid diseases. Iodine deficiency and excessive iodine, both cause goiter. There are many indicators for assessing the IDDs, such as measurement of thyroid size by palpation or ultrasonography, serum thyroid stimulating hormone, and thyroglobulin but these are less sensitive, costly and sometimes interpretation is difficult. Urinary iodine concentration (UIC) is a well-accepted, cost-efficient, and easily obtainable indicator of iodine status. Since the majority of iodine absorbed by the body is excreted in the urine, it is considered a sensitive marker of current iodine intake and can reflect recent changes in iodine status. Iodine requirements are greatly increased during pregnancy and lactation, owing to metabolic changes. During intrauterine life, maternal iodine is the only source of iodine for a fetus. UIC determines the iodine status of pregnant and lactating women. Breast milk is the only source of iodine for exclusively breastfed neonates and infants. Breast milk iodine concentration can be determined by UIC. UIC predicts the adverse health consequences of excessive iodine intake such as goiter, hypothyroidism, and hyperthyroidism. This review presents that iodine status in different groups of a population can be determined by UIC which will be helpful in assessing the iodine status in a community, finding out the cause of thyroid disorders, to predict the risk of adverse health effects of iodine deficiency and excessive iodine, and in making plan for iodine supplementation.Mediscope Vol. 5, No. 2: Jul 2018, Page 30-35

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The assessment of iodine status – populations, individuals and limitations

Annals of Clinical Biochemistry International Journal of Laboratory Medicine ◽

10.1177/0004563218774816 ◽

2018 ◽

Vol 56 (1) ◽

pp. 7-14 ◽

Cited By ~ 3

Author(s):

Patrick Wainwright ◽

Paul Cook

Keyword(s):

Iodine Deficiency ◽

Urinary Iodine ◽

Population Level ◽

Iodine Concentration ◽

Epidemiological Studies ◽

Health Concern ◽

Urinary Iodine Concentration ◽

Iodine Status ◽

The Uk

Iodine deficiency is a significant global health concern, and the single greatest cause of preventable cognitive impairment. It is also a growing public health concern in the UK particularly among pregnant women. Biomarkers such as urinary iodine concentration have clear utility in epidemiological studies to investigate population-level iodine status, but determination of iodine status in individuals is much more problematic with current assays. This article reviews the available biomarkers of iodine status and their relative utility at the level of both populations and individuals for the investigation of iodine deficiency and iodine excess.

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Thyroid stimulating hormone isn’t a sensitive indicator of iodine nutritional status in schoolchildren

Revista de Ciências Médicas e Biológicas ◽

10.9771/cmbio.v14i3.14990 ◽

2016 ◽

Vol 14 (3) ◽

pp. 350

Author(s):

Renata De Oliveira Campos ◽

Joaquim Custódio Silva Júnior ◽

Elton Estrela Ramos

Keyword(s):

Public Schools ◽

Nutritional Status ◽

Filter Paper ◽

Urinary Iodine ◽

Iodine Concentration ◽

Thyroid Stimulating Hormone ◽

Urinary Iodine Concentration ◽

Iodine Nutrition ◽

Cross Sectional ◽

Stimulating Hormone

Introduction: iodine deficiency disorders (IDD) are most common cause of preventable brain damage, mental retardation and stunted growth in children worldwide. Several indicators are complementary to urinary iodine concentration (UIC) for assessing iodine nutritional status, as thyroid size, thyroglobulin (Tg) and thyroid stimulating hormone (TSH) concentrations in the blood. Objective: analyze TSH in filter paper blood values and correlate with UIC in schoolchildren from public school at state of Bahia, Brazil. Methodology: cross-sectional study was conducted in 880 schoolchildren aged 6-14 years, randomly selected, of public schools in five cities of four micro-regions of Bahia between October 2013 and September 2014. TSH was analyzed in filter-paper blood and UIC were measured by adapted Sandell-Kolthoff reaction. Results: 880 blood samples on filter-paper were analyzed for TSH. The reference range previously established is 0.72 to 6.0 μUI/mL. Results of this research TSH dosage ranged from 0.24 μIU/L to 7.71 μIU/L, with a mean of 1.01±0.55 μUI/L and median 0.89 μUI/L. Only one child presented TSH greater than 6.0 (7.71 μIU/L); however, results of urinary iodine were consistent with a more than adequate nutrition iodine (243.70μg/L). There’ no correlation between TSH and UIC (r= 0.115; p= 0.002). Conclusion: in the present study, schoolchildren showed low values of TSH, but the mean UIC was indicative of adequate iodine nutrition.

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Indicators of Iodine Status in Pregnancy and Postpartum in a Group of Pregnant Women from Perimarine Area of Romania

ARS Medica Tomitana ◽

10.2478/arsm-2020-0013 ◽

2020 ◽

Vol 26 (2) ◽

pp. 63-69

Author(s):

Scrinic Olesea ◽

Delia Corina Elena ◽

Toma Geanina Mirela ◽

Circo Eduard

Keyword(s):

Pregnant Women ◽

Iodine Deficiency ◽

Urinary Iodine ◽

Iodine Concentration ◽

Iodine Intake ◽

Iodized Salt ◽

Urinary Iodine Concentration ◽

Urinary Creatinine ◽

Iodine Status ◽

In Pregnancy

Abstract Objective: Assessment of iodine nutritional status in pregnant women in the perimarine area of Romania, a region without iodine deficiency. Adequate iodine intake is the main source for normal thyroid function, ensuring the need for maternal thyroid hormones during pregnancy, but also for the development and growth of children in the fetal and postpartum period. Material and method: Prospective study performed on 74 pregnant women in the first 2 trimesters of pregnancy, originating from the perimarin area. The following indicators of iodine status were analyzed: urinary iodine concentration (UIC), the ratio between urinary iodine concentration and urinary creatinine (UIC/UCr), the prevalence of maternal goiter and the value of neonatal TSH (thyroid stimulating hormone). Results: The mean gestational age was 11 weeks. The ways of iodine intake are: iodized salt - 59.4%, iodized salt and iodine supplements- 23%, only iodine supplements -10.8% and 6.8% consume only non-iodized salt. The median of UIC was 133.03 mcg/l considered insufficient iodine intake (normal in pregnancy UIC >150 mcg/l), but the adjustment of UIC to urinary creatinine reveals a median of 152.83 mcg/g, a value that reflects an adequate iodine intake. The prevalence of goiter was 25.6% characteristic for a moderate iodine deficiency. The prevalence of neonatal TSH >5 mIU/L was registered in 18.8% characteristic of mild iodine deficiency. Conclusions: Monitoring of the iodine nutritional status is recommended for the prevention of disorders due to iodine deficiency under the conditions of universal salt iodization. Perimarine areas considered sufficient in iodine may show variations in iodine status in subpopulations under certain physiological conditions, such as pregnancy. An indicator of iodine status of the population is UIC, but the UIC/UCr ratio may be a more optimal indicator for pregnant women, to avoid possible overestimated results of iodine deficiency in pregnancy.

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Iodine Status and Thyroid Function in a Group of Seaweed Consumers in Norway

Nutrients ◽

10.3390/nu12113483 ◽

2020 ◽

Vol 12 (11) ◽

pp. 3483

Author(s):

Inger Aakre ◽

Lidunn Tveito Evensen ◽

Marian Kjellevold ◽

Lisbeth Dahl ◽

Sigrun Henjum ◽

...

Keyword(s):

Thyroid Function ◽

Urinary Iodine ◽

Iodine Content ◽

Iodine Concentration ◽

Iodine Intake ◽

Thyroid Stimulating Hormone ◽

Urinary Iodine Concentration ◽

Free Triiodothyronine ◽

Iodine Status ◽

Excessive Iodine

Seaweeds, or macroalgae, may be a good dietary iodine source but also a source of excessive iodine intake. The main aim in this study was to describe the iodine status and thyroid function in a group of macroalgae consumers. Two urine samples were collected from each participant (n = 44) to measure urinary iodine concentration (UIC) after habitual consumption of seaweed. Serum thyroid stimulating hormone (TSH), free thyroxine (fT4), free triiodothyronine (fT3), and peroxidase autoantibody (TPOAb), were measured in a subgroup (n = 19). A food frequency questionnaire and an iodine-specific 24 h recall were used to assess iodine intake and macroalgae consumption. The median (p25–p75) UIC was 1200 (370–2850) μg/L. Median (p25–p75) estimated dietary iodine intake, excluding macroalgae, was 110 (78–680) μg/day, indicating that seaweed was the major contributor to the iodine intake. TSH levels were within the reference values, but higher than in other comparable population groups. One third of the participants used seaweeds daily, and sugar kelp, winged kelp, dulse and laver were the most common species. Labelling of iodine content was lacking for a large share of the products consumed. This study found excessive iodine status in macroalgae consumers after intake of dietary seaweeds. Including macroalgae in the diet may give excessive iodine exposure, and consumers should be made aware of the risk associated with inclusion of macroalgae in their diet.

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

American Journal of Clinical Nutrition ◽

10.1093/ajcn/nqz118 ◽

2019 ◽

Vol 110 (4) ◽

pp. 949-958 ◽

Cited By ~ 2

Author(s):

Molla Mesele Wassie ◽

Philippa Middleton ◽

Shao Jia Zhou

Keyword(s):

Systematic Review ◽

Urinary Iodine ◽

Iodine Concentration ◽

Thyroid Stimulating Hormone ◽

School Age Children ◽

Urinary Iodine Concentration ◽

School Age ◽

Iodine Status ◽

Goiter Prevalence ◽

Reference Markers

ABSTRACT 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.

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Iodine concentration and prevalence of thyroid disease in older people after salt iodization in Turkey

Eastern Mediterranean Health Journal ◽

10.26719/2021.27.2.151 ◽

2021 ◽

Vol 27 (2) ◽

pp. 151-158

Author(s):

Volkan Atmis ◽

Buket Bülbül ◽

Remzi Bahşi ◽

Mesut Gümüşsoy ◽

Ahmet Yalçin ◽

...

Keyword(s):

Older People ◽

Thyroid Disease ◽

Demographic Data ◽

Urinary Iodine ◽

Iodine Concentration ◽

Needle Aspiration ◽

Thyroid Stimulating Hormone ◽

Urinary Iodine Concentration ◽

Salt Iodization ◽

Stimulating Hormone

Background: Iodine uptake is a main factor affecting thyroid disease. In Turkey, mandatory salt iodization began in 1999–2000. Aims: This study in 2009 determined the prevalence of thyroid diseases in older people in Mamak district, Ankara after iodization to ascertain if salt iodization alone is sufficient to reach adequate iodine levels in the older population. Methods: All Mamak residents ≥ 65 years were eligible for inclusion in the study. Demographic data and medical history were recorded. All participants had a thyroid ultrasound. Blood samples were taken to assess thyroid function and autoantibodies, and urine samples to assess iodine concentration. Participants with low levels of thyroid stimulating hormone underwent scintigraphy to assess thyroid uptake. Fine-needle aspiration biopsy was done of nodules ≥ 1.5 cm where thyroid stimulating hormone was not suppressed. Results: Of 1200 eligible residents, 979 were included. Their mean age was 70.9 (standard deviation (SD) 5.7) years; 49.7% were women. Mean urinary iodine concentration was 98 (SD 81.29) µg/L. Goitre was found in 18.2% (89/487) of women and 6.7% (33/492) of men (P < 0.001) and 43.8% (428/979) had nodules. Subclinical hypothyroidism was found in 5.8% (57/979) of the participants, overt hyperthyroidism in 0.8% (8/979), subclinical hyperthyroidism in 2.2% (22/979) and T3 thyrotoxicosis in 0.3% (3/979). Toxic multinodular goitre and toxic adenoma caused 80% of hyperthyroidism cases. Biopsy detected no malignant pathology. Conclusion: After salt iodization, iodine levels have not yet reached favourable levels in older people. Iodization of salt seems insufficient to achieve these levels in older people; alternative iodine supplementation should be considered.

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Breast Milk Iodine and Iodine Status of Breast-Fed Infants

Delta Medical College Journal ◽

10.3329/dmcj.v3i2.24426 ◽

2015 ◽

Vol 3 (2) ◽

pp. 74-77

Author(s):

Golam Morshed Molla ◽

M Iqbal Arslan ◽

Mafruha Tazkin Milky

Keyword(s):

Breast Milk ◽

Iodine Deficiency ◽

Urinary Iodine ◽

Iodine Concentration ◽

Urinary Iodine Excretion ◽

Urinary Iodine Concentration ◽

Minimum Concentration ◽

Iodine Status ◽

Lactating Mothers ◽

Breast Fed

Background: Breast milk is the only source of iodine for exclusively breast-fed infants. Iodine status of breast-fed infants depends on iodine in breast milk and also number of feeding in 24 hours. Iodine deficiency and iodine excess both have bad impact on infants health.Objective: To measure the iodine in breast milk and to evaluate iodine status of their breast-fed infants.Materials and method: This observational analytical study was carried out in the department of Biochemistry, Bangabandhu Sheikh Mujib Medical University, Dhaka with active cooperation of Kumudini Womens Medical College Hospital, Mirzapur, Tangail involving fifty lactating mothers and their exclusively breast-fed infants. Early morning urine and breast milk samples were collected in dry and clean plastic container free from any chemical contamination. Urinary iodine was used as indicator for assessing iodine status. All statistical analyses were done by using SPSS (statistical programme for social science) 12 version software package for Windows.Results: The median (range) urinary iodine concentration of lactating mothers and their breast-fed infants were 225.25 ?g/L (61.50-530.00) and 225.75 ?g/L (100.50-526.00) respectively. The median (range) breast-milk iodine concentration was 157 ?g/L (54.50-431.50) which was more than three times of recommended minimum concentration (50 ?g/L). Only 2 (4%) lactating mothers had mild biochemical iodine deficiency (UIE, 50-99 ?g/L). There was no biochemical iodine deficiency of breast-fed infants. Iodine in breast milk of lactating mothers was positively correlated with their urinary iodine excretion (p<0.01). Infants urinary iodine was positively correlated with iodine concentration in breast milk (p<0.01) and with urinary iodine of lactating mothers (p<0.01).Conclusion: Lactating mothers and their breast-fed infants in this study were iodine sufficient. If iodine content of breast-milk is within normal range, 10-12 numbers of feeding in 24 hours for infants is enough to get sufficient iodine from their mothers milk.Delta Med Col J. Jul 2015; 3(2): 74-77

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Maternal iodine status reflects the iodine status of their breast-fed infants

Mediscope ◽

10.3329/mediscope.v2i1.24734 ◽

2015 ◽

Vol 2 (1) ◽

pp. 13-17

Author(s):

GM Molla ◽

FH Mollah ◽

MT Milky ◽

DK Sunyal ◽

MI Arslan

Keyword(s):

Breast Milk ◽

Iodine Deficiency ◽

Urinary Iodine ◽

Iodine Concentration ◽

Urinary Iodine Excretion ◽

Urinary Iodine Concentration ◽

Minimum Concentration ◽

Iodine Status ◽

Lactating Mothers ◽

Breast Fed

The objective of the observational analytical study was to assess the iodine status of lactating mothers and their breast-fed infants and to evaluate whether maternal iodine status reflects the iodine status of their breast-fed infants. The study was carried out in the department of Biochemistry, Bangabandhu Sheikh Mujib Medical University, Dhaka with active cooperation of Kumudini Womens Medical College Hospital, Mirzapur, Tangail involving fifty lactating mothers and their exclusively breast-fed infants. Early morning urine and breast milk samples were collected in dry and clean plastic container free from any chemical contamination. Urinary iodine excretion (UIE) was used as indicator for assessing iodine status. The median (range) urinary iodine concentration of lactating mothers and their breast-fed infants were 225.3 ?g/L (61.5-530.0) and 225.8?g/L (100.5-526.0), respectively. Of the mothers, 96% (48) had no biochemical iodine deficiency (UIE ?100?g/L), only 4% (2) had mild biochemical iodine deficiency (UIE, 50-99?g/L). There was no biochemical iodine deficiency of breast-fed infants. The median breast-milk iodine concentration was 157?g/L which was more than three times of recommended minimum concentration (50?g/L). Iodine in breast milk of lactating mothers was positively correlated with their UIE (p < 0.01). Infants urinary iodine was positively correlated with iodine concentration in breast milk (p < 0.01) and also positively correlated with urinary iodine of lactating mothers (p < 0.01). Lactating mothers and their breast-fed infants in this study were iodine sufficient. Iodine status of exclusively breast-fed infants can be determined by the iodine status of their mothers.Mediscope Vol. 2, No. 1: 2015, Pages 13-17

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