Suboptimal Iodine Status and Low Iodine Knowledge in Young Norwegian Women

Previous studies have documented mild to moderate iodine deficiency in pregnant and lactating women in Norway. This study focused on non-pregnant young women because their future children may be susceptible to the adverse effects of iodine deficiency. We assessed urinary iodine concentration (UIC), iodine intake from food and supplements, and iodine knowledge in 403 non-pregnant women, mainly students, aged 18–30 years. Iodine concentration was measured in spot urine samples analyzed by inductively coupled plasma mass spectrometry and iodine intake was calculated from a self-reported food frequency questionnaire. Knowledge about iodine was collected through the self-administered, paper-based questionnaire. Median (p25–p75) UIC was 75 (42–130) µg/L and 31% had UIC < 50 µg/L. Habitual iodine intake was 100 (69–136) µg/day. In multiple regression models, supplemental iodine, use of thyroid medication, and iodine intake from food were positively associated with UIC, while vegetarian practice was negatively associated, explaining 16% of the variance. Approximately 40% of the young women had low iodine knowledge score and no differences were found between women in different study programs. Young women in Norway are mild to moderately iodine-deficient, and public health strategies are needed to improve and secure adequate iodine status.

Download Full-text

Vegans, Vegetarians and Pescatarians Are at Risk of Iodine Deficiency in Norway

Nutrients ◽

10.3390/nu12113555 ◽

2020 ◽

Vol 12 (11) ◽

pp. 3555

Author(s):

Synne Groufh-Jacobsen ◽

Sonja Y. Hess ◽

Inger Aakre ◽

Elin Lovise Folven Gjengedal ◽

Kristina Blandhoel Pettersen ◽

...

Keyword(s):

Iodine Deficiency ◽

Dietary Assessment ◽

Linear Regression Analysis ◽

Urinary Iodine ◽

Knowledge Score ◽

Iodine Concentration ◽

Multiple Linear Regression Analysis ◽

Iodine Intake ◽

Urinary Iodine Concentration ◽

Spot Urine

Low iodine intakes have been documented in different population groups in Norway. We aimed to assess iodine status, dietary intake, supplement and macroalgae use, and iodine knowledge in vegans, vegetarians and pescatarians. In this study, 115 vegans, 55 vegetarians and 35 pescatarians from the Oslo region of Norway, aged 18–60 years, participated. A spot urine sample was collected along with a dietary assessment of iodine intake, supplement and macroalgae use. The median urinary iodine concentration (MUIC) in vegans was 43 µg/L (moderate iodine deficiency), in vegetarians 67 µg/L and in pescatarians 96 µg/L (mild iodine deficiency). In multiple linear regression analysis, use of iodine supplements was one of the strongest predictors of UIC. About half of the participants had median 24-h iodine intakes below estimated average requirement (EAR) of 100 µg/day. Fifty percent had low knowledge score, while 27% had very low knowledge score. Vegans, vegetarians and possibly pescatarians in Norway, are unable to reach the recommended iodine intake merely from food and are dependent on iodine supplements. There is an urgent need for dietary guidance targeting vegans, vegetarians and pescatarians to avoid inadequate iodine intake in non-supplement users, as well as avoiding excess iodine intake in macroalgae users.

Download Full-text

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.

Download Full-text

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

Download Full-text

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.

Download Full-text

Oral Contraceptive Intake and Iodine Status in Young Women

Annals of Nutrition and Metabolism ◽

10.1159/000518135 ◽

2021 ◽

pp. 1-5

Author(s):

Carola Deischinger ◽

Doris Deischinger ◽

Irina Gessl ◽

Michael Krebs ◽

Rodrig Marculescu ◽

...

Keyword(s):

Oral Contraceptive ◽

Young Women ◽

Urinary Iodine ◽

Iodine Concentration ◽

Control Group ◽

Urinary Iodine Concentration ◽

Cross Sectional ◽

Iodine Status ◽

Spot Urine ◽

Urine Creatinine

Objective: Similar to pregnant women, women taking an oral contraceptive (OC) might have elevated iodine requirements due to the altered hormonal state. This is the first study aimed at investigating the prevalence of iodine deficiency and possible influences of OC intake on urine creatinine and iodine levels in young women. Methods: One hundred fifty-five women between the age of 18 and 35 years (62 taking an OC and 93 controls) participated in a cross-sectional pilot study at the Medical University of Vienna, which included a 1-spot urine sample and a questionnaire on OC intake as well as a food questionnaire. Results: The median urinary iodine concentration (UIC) in this study was 68 μg/L (41, 111 μg/L) suggesting an inadequate iodine status in the women according to the WHO guidelines. Median UIC (OC: 89 μg/L, IQR 55–120; control: 59 μg/L, IQR 39–91, p = 0.010) and urine creatinine (OC: median = 99.0 μg/L, IQR 74.9–175.5; control: 77.0 μg/L, IQR 49.6–147.2, p = 0.030) levels were significantly higher in OC women than in the control group. UIC corrected for urine creatinine was comparable between both groups. Conclusion: With similar creatinine-corrected UICs in both groups, OC intake might not have a significant impact on iodine status. However, the low median UIC in a vulnerable group of young women potentially conceiving in the following years points at the necessity of optimizing the iodine intake in the Austrian population and reiterates the insufficiency of the current iodine supplementation measures.

Download Full-text

Using seaweed as a supplement or a food ingredient to increase iodine status in women with low habitual intake

Proceedings of The Nutrition Society ◽

10.1017/s0029665120006655 ◽

2020 ◽

Vol 79 (OCE2) ◽

Author(s):

Katie Nicol ◽

Cara Swailes ◽

Layla Alahmari ◽

Emilie Combet

Keyword(s):

Urinary Iodine ◽

Iodine Concentration ◽

Iodine Intake ◽

Urinary Iodine Excretion ◽

Urinary Iodine Concentration ◽

Food Groups ◽

Food Ingredient ◽

Iodine Status ◽

Spot Urine ◽

Excess Iodine

AbstractIntroduction: Most consumers remain unaware of iodine sources in the diet. With no prophylaxis, iodine insufficiency remains a largely unappreciated issue in the UK. Including seaweed to the food supply represents a solution and opportunity but this supply needs to be carefully curated and calibrated, as excess iodine may be harmful for thyroid health. This project aimed to test the efficacy of a proof-of-concept reformulated food using seaweed as an ingredient source of iodine, to supplement women who have a habitual low iodine intake.Materials and Methods: Self-reported healthy women, pre-menopausal who avoid iodine-rich foods were randomised to: P1) reformulated food (pizza)with seaweed ingredient, or P2) a control food, similar to P1 but without supplemental iodine, or S1) control, empty capsules, or S2) PureSea Natural ascophyllum nodosum seaweed capsules, the ingredient used in P1. Capsules or food were to be consumed three times per week (providing 400μg iodine per intake). At least 10 spot urine samples were collected per person over at least 3 days preceding each study point. Urinary iodine was measured with a modified Sandell-Koltoff assay.Results: Participants (n = 96, median age 29, IQR 23–42) had a habitual iodine intake of 64μg/d (IQR 39–119, no detectable difference between groups). Dropout rates at 3-month were 41% (P1 &P2 each), 21% for S1, 11% for S2.Baseline urinary iodine concentration (UIC) was low/marginal, at 66μg/L (IQR 34-71), 64μg/L (IQR 40-96), 54μg/L (IQR 31-86) and 39μg/L (IQR 21-64) for P1, P2, S1 and S2 respectively (no difference between groups, p > 0.05).Change in UIC differed between groups at week-2 (p < 0.001), increasing in P1 & S2: by 45μg/L (IQR 2-69), and 35μg/L (IQR 13-48), respectively, decreasing in S1: -14μg/L (IQR –24-(–1)), with no change in group P2. This remained true for groups S1 & S2 when urinary iodine excretion was corrected for creatinine.After 3 months, differences in changes from baselines remained between groups (p < 0.01), with an increase in groups P1 and S2: 28μg/L (IQR 1-112), 43μg/L (IQR 23-93) but not groups P2 or S1. This remained true when UIC was corrected for creatinine.Changes in weight between and within groups were not detected at either time points, with group median changes within 2 kg of baseline weight.Discussion: Iodine-rich seaweed is effective in increasing the iodine status of women with a low habitual iodine intake, as a supplement, or as an ingredient in a cooked reformulated product. In term of feasibility, large attrition in the food groups P1 and P2 demands further attention, for interpretation of data and future translation of the findings.

Download Full-text

Changing Dietary Habits in Veneto Region over Two Decades: Still a Long Road to Go to Reach an Iodine-Sufficient Status

Nutrients ◽

10.3390/nu12082399 ◽

2020 ◽

Vol 12 (8) ◽

pp. 2399 ◽

Cited By ~ 1

Author(s):

Simona Censi ◽

Jacopo Manso ◽

Susi Barollo ◽

Alberto Mondin ◽

Loris Bertazza ◽

...

Keyword(s):

Dietary Habits ◽

Urinary Iodine ◽

Iodine Concentration ◽

Iodine Intake ◽

Iodized Salt ◽

Urinary Iodine Concentration ◽

Milk Product ◽

Veneto Region ◽

School Students ◽

Iodine Status

Background: Fifteen years after a nationwide voluntary iodine prophylaxis program was introduced, the aims of the present study were: (a) to obtain an up-to-date assessment of dietary iodine intake in the Veneto region, Italy; and (b) to assess dietary and socioeconomic factors that might influence iodine status. Methods: Urinary iodine concentration (UIC) was obtained in 747 school students (median age 13 years; range: 11–16 years). Results: The median UIC was 111 μg/L, with 56% of samples ≥ 100 μg/L, but 26% were < 50 μg/L, more frequently females. Iodized salt was used by 82% of the students. The median UIC was higher among users of iodized salt than among non-users, 117.0 ug/L versus 90 ug/L (p = 0.01). The median UIC was higher in regular consumers of cow’s milk than in occasional consumers, 132.0 μg/L versus 96.0 μg/L (p < 0.01). A regular intake of milk and/or the use of iodized salt sufficed to reach an adequate median UIC, although satisfying only with the combined use. A trend towards higher UIC values emerged in regular consumers of cheese and yogurt. Conclusion: Iodine status has improved (median UIC 111.0 μg/L), but it is still not adequate as 26% had a UIC < 50 μg/L in the resident population of the Veneto region. A more widespread use of iodized salt but also milk and milk product consumption may have been one of the key factors in achieving this partial improvement.

Download Full-text

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.

Download Full-text

Current iodine status in Japan: A cross-sectional nationwide survey of schoolchildren, 2014–2019

The Journal of Clinical Endocrinology & Metabolism ◽

10.1210/clinem/dgab919 ◽

2021 ◽

Author(s):

Yozen Fuse ◽

Yoshiya Ito ◽

Yoshimasa Shishiba ◽

Minoru Irie

Keyword(s):

Urinary Iodine ◽

Nationwide Survey ◽

Iodine Concentration ◽

Iodine Intake ◽

Urinary Iodine Excretion ◽

Urinary Iodine Concentration ◽

Cross Sectional ◽

Iodine Status ◽

Iodine Excretion ◽

Cr Concentration

Abstract Context Japan has been regarded as a long-standing iodine sufficient country without iodine fortification; however, data on nationwide iodine status is lacking. Objective This study aimed to characterize the iodine status in Japan. Methods From 2014 through 2019 a nationwide school-based survey was conducted across all districts in Japan. Urinary iodine concentration (UIC), creatinine (Cr) concentration and anthropometry were assessed in healthy school-aged children (SAC) aged 6 to 12 years. Their iodine status is regarded as generally representative of the nation's iodine status. Results A total of 32,025 children participated. The overall median UIC was 269 μg/L which was within the WHO’s adequacy range. There was a regional difference in UIC values within 14 regions, and the lowest and highest median UIC were found in Tanegashima Island (209 μg/L) and Nakashibetsu, Hokkaido (1,071 μg/L), respectively. The median UIC ≥ 300 μg/L was observed in 12 out of 46 regions. By using estimated 24-h urinary iodine excretion (UIE), the prevalence of SAC exceeding the upper tolerable limit of iodine for Japanese children was from 5.2 to 13.7%. The UIC values did not change with age, BSA and BMI percentile, while the Cr concentration simultaneously increased suggesting the effect of urinary creatinine on UI/Cr and estimated 24-h UIE values. Conclusions The iodine intake of Japanese people is adequate, but in some areas it is excessive. The incidence and prevalence of thyroid disorders associated with iodine intake should be obtained especially in the areas where high amounts of iodine are consumed.

Download Full-text

Iodine intake from supplements and diet during pregnancy and child cognitive and motor development: the INMA Mother and Child Cohort Study

Journal of Epidemiology & Community Health ◽

10.1136/jech-2017-209830 ◽

2017 ◽

Vol 72 (3) ◽

pp. 216-222 ◽

Cited By ~ 22

Author(s):

Mario Murcia ◽

Mercedes Espada ◽

Jordi Julvez ◽

Sabrina Llop ◽

Maria-Jose Lopez-Espinosa ◽

...

Keyword(s):

Cohort Study ◽

Motor Function ◽

Iodine Deficiency ◽

Motor Development ◽

Urinary Iodine ◽

Iodine Concentration ◽

Iodine Intake ◽

Urinary Iodine Concentration ◽

Neuropsychological Development ◽

Salt Consumption

BackgroundThe effect of mild-to-moderate maternal iodine deficiency on the neuropsychological development of their offspring is uncertain. We aimed to assess the association between iodine status during pregnancy and the cognitive and motor development of children at 4–5 years.MethodsWe conducted a prospective cohort study in four Spanish regions with recruitment of pregnant women between 2003 and 2008 and follow-up of their children up to 4–5 years (mean (SD)=4.8 (0.6)). Cognitive and motor function was assessed in 1803 children using the McCarthy Scales of Children’s Abilities. Dietary iodine and supplementation were measured through questionnaires twice during pregnancy. Urinary iodine concentration (UIC) was measured in spot samples. The residuals of a regression of UIC against creatinine were used to define a variable corrected for creatinine (UIC~Cr).ResultsNeither iodine supplements nor iodised salt consumption or maternal UIC were associated with cognitive or motor function. After adjusting for creatinine, children of women with UIC~Cr <100 µg/L had 3.93 (95% CI −6.18 to –1.69) general cognitive scores lower than the reference (150–249 µg/L). Dietary iodine was inversely associated with motor scores and milk but not other dairy products or seafood consumption accounted for this association (beta: −1.36; 95% CI −2.12 to –0.61; per one daily milk serving).ConclusionsWe found an association between low maternal urinary iodine and lower cognitive scores in childhood, although only when corrected for creatinine, adding to the evidence that iodine deficiency may have potential harmful effects on neurodevelopment. Iodine supplementation does not appear to improve child’s neurodevelopment at 4–5 years.

Download Full-text