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

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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Mild to Moderate Iodine Deficiency and Inadequate Iodine Intake in Lactating Women in the Inland Area of Norway

Nutrients ◽

10.3390/nu12030630 ◽

2020 ◽

Vol 12 (3) ◽

pp. 630 ◽

Cited By ~ 1

Author(s):

Synne Groufh-Jacobsen ◽

Lise Mette Mosand ◽

Ingvild Oma ◽

Kjersti Sletten Bakken ◽

Beate Stokke Solvik ◽

...

Keyword(s):

Human Milk ◽

Infant Health ◽

Urinary Iodine ◽

Iodine Concentration ◽

Iodine Intake ◽

Public Health Care ◽

Urinary Iodine Concentration ◽

Cross Sectional ◽

Lactating Women ◽

Iodine Status

Breastfed infants are dependent on an adequate supply of iodine in human milk for the production of thyroid hormones, necessary for development of the brain. Despite the importance of iodine for infant health, data on Norwegian lactating women are scarce. We measured iodine intake and evaluated iodine status and iodine knowledge among lactating women. From October to December 2018, 133 mother–infant pairs were recruited in a cross-sectional study through two public health care centers in Lillehammer and Gjøvik. Each of the women provided two human milk specimens, which were pooled, and one urine sample for analysis of iodine concentration. We used 24-h dietary recall and food frequency questionnaire (FFQ) to estimate short-term and habitual iodine intake from food and supplements. The median (P25, P75) human milk iodine concentration (HMIC) was 71 (45, 127) µg/L—of which, 66% had HMIC <100 µg/L. The median (P25, P75) urinary iodine concentration (UIC) was 80 µg/L (52, 141). The mean (± SD) 24-h iodine intake and habitual intake was 78 ± 79 µg/day and 75 ± 73 µg/day, respectively. In conclusion, this study confirms inadequate iodine intake and insufficient iodine status among lactating women in the inland area of Norway and medium knowledge awareness about iodine.

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The impact of iodised salt or iodine supplements on iodine status during pregnancy, lactation and infancy

Public Health Nutrition ◽

10.1017/s1368980007360965 ◽

2007 ◽

Vol 10 (12A) ◽

pp. 1584-1595 ◽

Cited By ~ 50

Author(s):

Michael B Zimmermann

Keyword(s):

Pregnant Women ◽

Urinary Iodine ◽

Iodine Concentration ◽

Iodine Intake ◽

Urinary Iodine Concentration ◽

Life Stages ◽

Lactating Women ◽

Iodine Status ◽

Iodised Salt ◽

The Impact

AbstractObjectives:Monitoring of iodine status during pregnancy, lactation and infancy is difficult as there are no established reference criteria for urinary iodine concentration (UI) for these groups; so it is uncertain whether iodized salt programs meet the needs of these life stages.Design and Subjects:The method used in this paper was: 1) to estimate the median UI concentration that reflects adequate iodine intake during these life stages; and 2) to use these estimates in a review of the literature to assess whether salt iodisation can control iodine deficiency in pregnant and lactating women, and their infants.Results:For pregnancy, recommended mean daily iodine intakes of 220-250 μg were estimated to correspond to a median UI concentration of about 150 μg l− 1, and larger surveys from the iodine sufficient countries have reported a median UI in pregnant women ≥ 140 μg l− 1. Iodine supplementation in pregnant women who are mild-to-moderately iodine deficient is beneficial, but there is no clear affect on maternal or newborn thyroid hormone levels. In countries where the iodine intake is sufficient, most mothers have median breast milk iodine concentration (BMIC) greater than the concentration (100-120 μg l− 1) required to meet an infant's needs. The median UI concentration during infancy that indicates optimal iodine nutrition is estimated to be ≥ 100 μg l− 1. In iodine-sufficient countries, the median UI concentration in infants ranges from 90-170 μg l− 1, suggesting adequate iodine intake in infancy.Conclusions:These findings suggest pregnant and lactating women and their infants in countries with successful sustained iodised salt programs have adequate iodine status.

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Iodine nutrition in pregnancy and lactation in Iran

Public Health Nutrition ◽

10.1017/s1368980007360977 ◽

2007 ◽

Vol 10 (12A) ◽

pp. 1596-1599 ◽

Cited By ~ 22

Author(s):

Fereidoun Azizi

Keyword(s):

Pregnant Women ◽

Urinary Iodine ◽

Thyroid Volume ◽

Iodine Concentration ◽

Iodine Intake ◽

Urinary Iodine Excretion ◽

Urinary Iodine Concentration ◽

Lactating Women ◽

Iodine Excretion ◽

Pregnancy And Lactation

AbstractObjective: To describe studies evaluating urinary iodine excretion during pregnancy and lactation in women living in cities with adequate or more than adequate iodine intake.Design: Cross-sectional study conducted between 1996 and 1998 in pregnant women and a study of lactating women conducted in 2003.Settings and Subjects: Pregnant women attending prenatal clinics in four cities in the Islamic Republic of Iran. Urinary iodine excretion and thyroid volume was measured in 403 women. In a second study, 100 lactating women from Taleghani Hospital in Gorgan, Iran were evaluated for thyroid size, and both urinary and breast milk iodine concentrations were determined.Results: In Rasht city, 84% of pregnant women had a urinary iodine concentration of ≥ 200 μg l-1, while in the other cities this percentage ranged from 45 to 55%. When data were combined for the cities of Ilam, Isfahan and Tehran, where women have an adequate or more than adequate median urinary iodine concentration, 51% of pregnant women had a urinary iodine concentration less than that recommended during pregnancy. In Rasht, where the median urinary iodine concentration indicates an excessive iodine intake, 15.4% of pregnant women had a urinary iodine concentration < 200 μg l-1. The mean urinary iodine concentration in lactating women was 250 μg l-1, and 16% of women had a urinary iodine concentration < 100 μg l-1. Grade 1 goitre was present in 8% of lactating women, and another 8% had grade 2 goitre.Conclusions: Findings of this study call for further attention to iodine intake during pregnancy and lactation. The currently recommended intake of iodine through universal salt iodisation may not be adequate for pregnant and lactating women, and supplementation during pregnancy and lactation should be further considered in light of the latest recommendations.

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Iodine nutrition of pregnant and lactating women in Hong Kong, where intake is of borderline sufficiency

Public Health Nutrition ◽

10.1017/s1368980007360989 ◽

2007 ◽

Vol 10 (12A) ◽

pp. 1600-1601 ◽

Cited By ~ 9

Author(s):

Annie WC Kung

Keyword(s):

Hong Kong ◽

Breast Milk ◽

Urinary Iodine ◽

Iodine Concentration ◽

Iodine Intake ◽

Normal Serum ◽

Urinary Iodine Concentration ◽

Iodine Nutrition ◽

Cross Sectional ◽

Lactating Women

AbstractObjective: To describe the iodine nutrition of pregnant and lactating women in Hong Kong, where intake is of borderline sufficiency.Design: Review of cross-sectional and prospective studies.Setting: China, Hong Kong Special Administrative Region (SAR).Subjects: Pregnant and lactating women.Results: Studies of pregnant women in Hong Kong SAR have revealed an increase in the urinary iodine (UI) concentration as pregnancy advances. A significant percentage of women had a sub-normal serum thyroid hormone concentration at full term. Although iodine is concentrated by the mammary gland, 19% of all mothers had low iodine concentrations in their breast milk. The moderate correlation between the concentrations of iodine in breast milk and urine suggests that an adequate maternal urinary iodine concentration cannot reliably indicate that an infant is getting enough iodine in breast milk. Therefore, some breast-fed infants may still be at risk of low iodine intake, and additional iodine supplements, other than salt iodisation, would be warranted in this population.Conclusions: The currently recommended intake of iodine through universal salt iodisation may not be adequate for pregnant and lactating women, and supplementation during pregnancy and lactation should be further considered in light of the latest recommendations.

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Relationship Between Thyroid Hormonal Status in Patients with a Hypothyroid Form of Hashimoto’s Thyroiditis and Iodine Concentrations in Drinking Water

Biological Trace Element Research ◽

10.1007/s12011-021-02640-2 ◽

2021 ◽

Author(s):

Olha Kasiyan ◽

Halyna Tkachenko ◽

Natalia Kurhaluk ◽

Svitlana Yurchenko ◽

Alek Manenko

Keyword(s):

Hashimoto’S Thyroiditis ◽

Iodine Concentration ◽

Iodine Intake ◽

Thyroid Stimulating Hormone ◽

Hashimoto's Thyroiditis ◽

Thyroid Peroxidase ◽

Supply Network ◽

Thyroid Status ◽

Thyroglobulin Antibodies ◽

Regressive Analysis

AbstractThe current study aimed to identify correlative and regressive dependencies between the water iodine concentration and the levels of TSH (thyroid-stimulating hormone), thyroglobulin antibodies (TgAbs), and thyroid peroxidase (TPOAb) in the serum of 168 in patients (34 men and 134 women) with a hypothyroid form of Hashimoto’s thyroiditis who use water from the supply network and individual wells. Based on the water iodine concentration, low and moderate degrees of iodine endemia in the location of the patients were determined. In the groups of men and women using water from different water supply sources, there were direct correlations between the water iodine concentrations and the TgAbs and TPOAb titers as well as an inverse dependence between iodine and TSH levels. Multivariate regressive analysis indicated that TgAb and TSH in the group of women using water from a supply network and TPOAb titers in the group of women using well water were independent factors associated with water iodine concentrations. Statistically significant correlations and regressive dependencies between the water iodine concentrations and the biomarkers of the thyroid status of the patients indicate the risk of Hashimoto’s thyroiditis progression, especially among women with additional iodine intake.

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The Reliability of Iodine Concentration in Diaper-Retrieved Infant Urine Using Urine Collection Pads, and in Their Mothers’ Breastmilk

Biomolecules ◽

10.3390/biom10020295 ◽

2020 ◽

Vol 10 (2) ◽

pp. 295

Author(s):

Kjersti Sletten Bakken ◽

Ingvild Oma ◽

Synne Groufh-Jacobsen ◽

Beate Stokke Solvik ◽

Lise Mette Mosand ◽

...

Keyword(s):

Intraclass Correlation ◽

Urinary Iodine ◽

Correlation Coefficients ◽

Iodine Concentration ◽

Cross Sectional Study ◽

Iodine Intake ◽

Public Healthcare ◽

Urinary Iodine Concentration ◽

Childbearing Age ◽

Cross Sectional

Mild to moderate iodine deficiency is common among women of childbearing age. Data on iodine status in infants are sparse, partly due to the challenges in collecting urine. Urinary iodine concentration (UIC) is considered a good marker for recent dietary iodine intake and status in populations. The aim of this study was to investigate the reliability of iodine concentration measured in two spot-samples from the same day of diaper-retrieved infant urine and in their mothers’ breastmilk. We collected urine and breastmilk from a sample of 27 infants and 25 mothers participating in a cross-sectional study at two public healthcare clinics in Norway. The reliability of iodine concentration was assessed by calculating the intraclass correlation coefficients (ICC) and the coefficient of variation (CV). The ICC for infants’ urine was 0.64 (95% confidence interval (CI) 0.36–0.82), while the ICC for breastmilk was 0.83 (95% CI 0.65–0.92) Similarly, the intraindividual CV for UIC was 0.25 and 0.14 for breastmilk iodine concentration (BIC). Compared to standard methods of collecting urine for measuring iodine concentration, the diaper-pad collection method does not substantially affect the reliability of the measurements.

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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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Amniotic fluid iodine concentrations do not vary in pregnant women with varying iodine intake

British Journal Of Nutrition ◽

10.1017/s0007114507862398 ◽

2008 ◽

Vol 99 (6) ◽

pp. 1178-1181 ◽

Cited By ~ 18

Author(s):

Eduardo García-Fuentes ◽

Manuel Gallo ◽

Laureano García ◽

Stephanie Prieto ◽

Javier Alcaide-Torres ◽

...

Keyword(s):

Amniotic Fluid ◽

Pregnant Women ◽

Urinary Iodine ◽

Public Health Problem ◽

Iodine Concentration ◽

Iodine Intake ◽

Iodized Salt ◽

Cross Sectional ◽

International Agencies ◽

Multivitamin Supplement

Iodine deficiency is an important clinical and public health problem. Its prevention begins with an adequate intake of iodine during pregnancy. International agencies recommend at least 200 μg iodine per d for pregnant women. We assessed whether iodine concentrations in the amniotic fluid of healthy pregnant women are independent of iodine intake. This cross-sectional, non-interventional study included 365 consecutive women who underwent amniocentesis to determine the fetal karyotype. The amniocentesis was performed with abdominal antisepsis using chlorhexidine. The iodine concentration was measured in urine and amniotic fluid. The study variables were the intake of iodized salt and multivitamin supplements or the prescription of a KI supplement. The mean level of urinary iodine was 139·0 (sd94·5) μg/l and of amniotic fluid 15·81 (sd7·09) μg/l. The women who consumed iodized salt and those who took a KI supplement had significantly higher levels of urinary iodine than those who did not (P = 0·01 andP = 0·004, respectively). The urinary iodine levels were not significantly different in the women who took a multivitamin supplement compared with those who did not take this supplement, independently of iodine concentration or multivitamin supplement. The concentrations of iodine in the amniotic fluid were similar, independent of the dietary iodine intake. Urine and amniotic fluid iodine concentrations were weakly correlated, although the amniotic fluid values were no higher in those women taking a KI supplement. KI prescription at recommended doses increases the iodine levels in the mother without influencing the iodine levels in the amniotic fluid.

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Effect of Irrigation Water Containing Iodine on Plant Physiological Processes and Elemental Concentrations of Cabbage (Brassica oleracea L. var. capitata L.) and Tomato (Solanum lycopersicum L.) Cultivated in Different Soils

Agronomy ◽

10.3390/agronomy10050720 ◽

2020 ◽

Vol 10 (5) ◽

pp. 720 ◽

Cited By ~ 1

Author(s):

Péter Dobosy ◽

Viktória Vetési ◽

Sirat Sandil ◽

Anett Endrédi ◽

Krisztina Kröpfl ◽

...

Keyword(s):

Irrigation Water ◽

Soil Type ◽

Chlorophyll Concentration ◽

Iodine Concentration ◽

Dry Mass ◽

Iodine Intake ◽

Physiological Characteristic ◽

Tomato Fruits ◽

Sandy Silt ◽

Iodine Treatment

Iodine uptake and translocation was studied in cabbage and tomato cultivated on different soil types (sand, sandy silt, silt) by applying irrigation water containing iodine at concentrations of 0.1 and 0.5 mg/L. Iodine treatment at the concentrations applied did not significantly influence the photosynthetic efficiency and chlorophyll concentration of cabbage and tomato leaves. The growth of cabbage leaves cultivated on sand and sandy silt soil with iodine treatment was slightly stimulated, while, on silt soil, it remained unchanged; for tomato plant parts, independent of the soil-type, the dry mass values remained constant. It can be concluded that iodine treatment had no negative effect on the physiological characteristic of cabbage and tomato plants. Applying 0.5 mg/L in the irrigation water, the highest biofortification with iodine was achieved in plants cultivated in sandy soil and the iodine concentration calculated in the dry matter amounted to 10 and 3.6 mg/kg in the leaves and fruits of cabbage and tomato, respectively. Considering the iodine and moisture content of cabbage leaves and tomato fruits, the consumption of 100 g of fresh vegetable would cover about 80% and 15% of the recommended iodine intake, respectively. The presence of iodine resulted in a reduction in Fe and P concentrations in tomato fruits independent of the soil-type; however, the concentration of Mg, Cu, Mn, Zn, and B remained practically unchanged. However, for cabbage, no similar trend for Fe and P was observed.

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