Sufficient Iodine Intake Research Articles

Hipotiroidismo

Hypothyroidism is one of the most prevalent endocrine diseases in routine clinical practice. The most common etiology worldwide is iodine deficiency. In countries with sufficient iodine intake, it is Hashimoto's thyroiditis. In this sense, it is important to take an adequate case history and physical examination for a diagnosis, although confirmation is determined by biochemical analysis. The universal screening protocol consists of the initial TSH measurement and, in case of abnormal values, FT4 measurement. The normal limits for TSH are controversial and continue to be the subject of debate today. They have associated conditioning factors such as pregnancy or the normal limit in the older adult population. Replacement therapy is not always indicated, but when it is, oral levothyroxine is the treatment of choice.

The Potential of Iodine as A Treatment for Breast Cancer: A Narrative Review

Breast cancer is a cancer with the highest incidence of death in women in the world. Studies state that breast cancer can capture iodine molecules, making this substance a potential alternative therapy for further research and study. Opportunities for iodine as a treatment for breast cancer are supported by the fact that iodine is a molecular element widely available in nature, such as in food, plants, and oceans, so iodine is an easy substance to obtain. This article explores the potential of iodine as a treatment for breast cancer. The method used is a literature review study, in which literature is collected through the PubMed, Science Direct, and Google Scholar databases published from 2013-2022, and full text is available. The results of the review of the 10 articles obtained are the exposure of sources and intake of iodine, the physiological effects of iodine, and the effects of iodine on breast cancer cells. Iodine has the potential as a substance with anticancer activity through antiproliferative mechanisms, apoptosis, and immune system activation when given in sufficient quantities and at appropriate doses. The mechanism of iodine affecting breast cancer cells occurs through direct and indirect effects on the biological processes of cancer cells. These mechanisms occur molecularly in cancer cells by intermediary mitochondrial organelles and specific ligands in the cell. Iodine can also be combined with breast cancer chemotherapy, such as doxorubicin, which gives a good treatment response after chemotherapy. This is important to ensure sufficient daily intake of iodine for the body, especially in patients with breast cancer.

Dietary Iodine Intake and Related Factors among Secondary School Students in Macao.

Iodine is a crucial micronutrient that is indispensable for optimal physical growth and cognitive maturation. However, the dietary iodine intake status of Macao's population is unknown. Therefore, a cross-sectional study was conducted to assess the dietary iodine intake of Macao secondary school students. Four hundred and twenty-four students filled in a self-developed, 61-item, iodine-specific food frequency questionnaire (I-FFQ). The dietary iodine intake was calculated based on the I-FFQ and food composition database. The median daily iodine intake of the students was 74.4 µg, which is lower than the 150 µg recommended by the World Health Organization (WHO). The intake frequency of dried seaweed and kelp was also low, with 49.3% and 64.2% of students consuming these foods infrequently over a month. In conclusion, the dietary iodine intake of secondary school students in Macao was inadequate. It is recommended that individuals should take the initiative to gain iodine-related knowledge. Students are advised to eat a variety of iodine-rich foods, such as seaweed and seafood, as part of a healthy, balanced diet to ensure sufficient iodine intake. Furthermore, it will be necessary to measure urinary iodine for the iodine status assessment of the Macao population in future.

Inadequate Iodine Intake in Mothers of Young Children in Innlandet County, Norway

BackgroundIodine has an essential role in child growth and brain development. Thus, sufficient iodine intake is particularly important in women of childbearing age and lactating women. ObjectivesThis cross-sectional study aimed to describe iodine intake in a large random sample of mothers of young children (aged ≤2 y) living in Innlandet County, Norway. MethodsFrom November 2020 to October 2021, 355 mother–child pairs were recruited from public health care centers. Dietary data were obtained using two 24-h dietary recalls (24-HRs) per woman and an electronic FFQ. The Multiple Source Method was used to estimate the usual iodine intake from the 24-HR assessment. ResultsBased on the 24-HRs, the median (P25, P75) usual iodine intake from food was 117 μg/d (88, 153) in nonlactating women and 129 μg/d (95, 176) in lactating women. The median (P25, P75) total usual iodine intake (from food combined with supplements) was 141 μg/d (97, 185) in nonlactating women and 153 μg/d (107, 227) in lactating women. Based on the 24-HRs, 62% of the women had a total iodine intake below the recommendations (150 μg/d in nonlactating women and 200 μg/d in lactating women), and 23% of them had an iodine intake below the average requirement (100 μg/d). The reported use of iodine-containing supplements was 21.4% in nonlactating women and 28.9% in lactating women. In regular users of iodine-containing supplements (n = 63), supplements contributed to an average of 172 μg/d of iodine. Among regular iodine supplement users, 81% reached the recommendations compared with 26% of nonsupplement users (n = 237). The iodine intake estimated by FFQ was substantially higher than that estimated by 24-HRs. ConclusionsMaternal iodine intake in Innlandet County was inadequate. This study confirms the need for action to improve iodine intake in Norway, particularly among women of childbearing age.

Comparison of a digital iodine-specific dietary screener with 24-hour recall and urinary iodine concentration.

Mild-to-moderate iodine deficiency remains a problem worldwide, including in Norway. Of particular, concern is fertile, pregnant and lactating women. The Norwegian Dairy Council developed a digital iodine-specific dietary screener (I-screener) for the assessment of iodine intake levels but has yet to be validated. The aim was thus to investigate the relative validity of the I-screener by comparing estimates of iodine intake from the I-screener against a single 24-hour recall (24HR) and urinary iodine concentration (UIC) in fertile women. Healthy females were recruited in Bergen in August-December 2021. Six spot-urine samples from six consecutive days were collected into a pooled sample to assess UIC. Each participant completed a single administration of the I-screener and the 24HR. The estimated daily iodine intake from the I-screener was compared with the estimations from the 24HR and UIC. Seventy-two women aged 19-39 completed the study. The median UIC was 76 μg/l. Compared with the 24HR, the I-screener placed 83 % of the participants in the same/adjacent tertial, with a slight agreement between the methods (Cohen's kappa = 0⋅187). The present study shows an acceptable correlation between the I-screener and the 24HR (r = 0⋅318), but not between the I-screener and UIC (r = 0⋅122). Despite its varying iodine estimate abilities, the I-screener may be used as an initial screening tool to rank fertile women on an individual level into deficient inadequate, and sufficient iodine intake. However, due to the relatively high risk of misclassification, further assessment of iodine status should follow.

Seasonality of Hashimoto Thyroiditis: Infodemiology Study of Google Trends Data

Background Hashimoto thyroiditis (HT) is an autoimmune thyroid disease and the leading cause of hypothyroidism in areas with sufficient iodine intake. The quality-of-life impact and financial burden of hypothyroidism and HT highlight the need for additional research investigating the disease etiology with the aim of revealing potential modifiable risk factors. Objective Implementation of measures against such risk factors, once identified, has the potential to lessen the financial burden while also improving the quality of life of many individuals. Therefore, we aimed to examine the potential seasonality of HT in Europe using the Google Trends data to explore whether there is a seasonal characteristic of Google searches regarding HT, examine the potential impact of the countries’ geographic location on the potential seasonality, and identify potential modifiable risk factors for HT, thereby inspiring future research on the topic. Methods Monthly Google Trends data on the search topic “Hashimoto thyroiditis” were retrieved in a 17-year time frame from January 2004 to December 2020 for 36 European countries. A cosinor model analysis was conducted to evaluate potential seasonality. Simple linear regression was used to estimate the potential effect of latitude and longitude on seasonal amplitude and phase of the model outputs. Results Of 36 included European countries, significant seasonality was observed in 30 (83%) countries. Most phase peaks occurred in spring (14/30, 46.7%) and winter (8/30, 26.7%). A statistically significant effect was observed regarding the effect of geographical latitude on cosinor model amplitude (y = –3.23 + 0.13 x; R2=0.29; P=.002). Seasonal increases in HT search volume may therefore be a consequence of an increased incidence or higher disease activity. It is particularly interesting that in most countries, a seasonal peak occurred in spring and winter months; when viewed in the context of the statistically significant impact of geographical latitude on seasonality amplitude, this may indicate the potential role of vitamin D levels in the seasonality of HT. Conclusions Significant seasonality of HT Google Trends search volume was observed in our study, with seasonal peaks in most countries occurring in spring and winter and with a significant impact of latitude on seasonality amplitude. Further studies on the topic of seasonality in HT and factors impacting it are required.

Infant iodine status and associations with maternal iodine nutrition, breast-feeding status and thyroid function.

Adequate iodine nutrition during infancy is required for normal thyroid function and, subsequently, brain development. However, data on infant iodine status in the first year of life are scarce. This study aimed to describe infant iodine status and further explore its associations with maternal iodine nutrition, breast-feeding status and thyroid function. In this cohort study, 113 infants were followed up at ages 3, 6 and 11 months in Norway. Infant and maternal urinary iodine concentration (UIC), maternal iodine intake, breast milk iodine concentration (BMIC), breast-feeding status and infant thyroid function tests were measured. The median infant UIC was 82 µg/l at the age of 3 months and below the WHO cut-off of 100 µg/l. Infant UIC was adequate later in infancy (median 110 µg/l at ages 6 and 11 months). Infant UIC was associated positively with maternal UIC (β = 0·33, 95 % CI (0·12, 0·54)), maternal iodine intake (β = 0·30, 95 % CI (0·18, 0·42)) and BMIC (β = 0·46, 95 % CI (0·13, 0·79)). Breastfed infants had lower median UIC compared with formula-fed infants at ages 3 months (76 v. 190 µg/l) and 6 months (105 v. 315 µg/l). Neither infant UIC nor BMIC were associated with infant thyroid function tests. In conclusion, breastfed infants in Norway are at risk of insufficient iodine intake during the first months of life. Maternal iodine nutrition is important for providing sufficient iodine intake in infants, and awareness of promoting adequate iodine nutrition for lactating women should be prioritised.

Low-Iodine Diet of 4 Days Is Sufficient Preparation for 131I Therapy in Differentiated Thyroid Cancer Patients

ContextNo consensus exists about the optimal duration of the low-iodine diet (LID) in the preparation of 131I therapy in differentiated thyroid cancer (DTC) patients.ObjectiveThis work aimed to investigate if a LID of 4 days is enough to achieve adequate iodine depletion in preparation for 131I therapy. In addition, the nutritional status of the LID was evaluated.MethodsIn this prospective study, 65 DTC patients treated at 2 university medical centers were included between 2018 and 2021. The patients collected 24-hour urine on days 4 and 7 of the LID and kept a food diary before and during the LID. The primary outcome was the difference between the 24-hour urinary iodine excretion (UIE) on both days.ResultsThe median 24-hour UIE on days 4 and 7 of the LID were not significantly different (36.1 mcg [interquartile range, 25.4-51.2 mcg] and 36.5 mcg [interquartile range, 23.9-47.7 mcg], respectively, P = .43). On day 4 of the LID, 72.1% of the DTC patients were adequately prepared (24-hour UIE < 50 mcg), and 82.0% of the DTC patients on day 7 (P = .18). Compared to the self-reported regular diet, DTC patients showed a significantly (P < .01) lower percentage of nutrient intake (calories, protein, calcium, iodine, and water) during the LID.ConclusionThe 24-hour UIE on day 4 of the LID did not differ from day 7, and therefore shortening the LID from 7 to 4 days seems justified to prepare DTC patients for 131I therapy in areas with sufficient iodine intake and may be beneficial to maintain a sufficient nutritional intake during DTC treatment.

Lower educational status interferes with maternal iodine intake during both pregnancy and lactation.

ObjectiveTo investigate factors affecting conscious iodine intake among pregnant and lactating women in a rural area in Hungary.MethodsPregnant women were studied and followed during lactation. Urinary and breast milk iodine concentration (UIC and MIC) were measured by inductively coupled plasma mass spectrometry. Potential interfering factors, including age, educational status and smoking were assessed.ResultsDuring pregnancy and lactation, mild iodine deficiency was observed; median UIC were 66 and 49 µg/L, respectively. Educational status was found to be a strong determinant of both iodine nutrition and smoking status during pregnancy (P < 0.01 and P < 0.001) and lactation (P < 0.001 and P < 0.01). While smoking and non-smoking lactating mothers had similar concentrations of urinary iodine (median UIC: 47 and 51 µg/L, P = 0.95), the breast milk of smoking mothers contained less iodine (median MIC: 150 and 203 µg/L, P = 0.03).ConclusionsBoth low iodine intake and smoking contribute to the higher risk of iodine deficiency in women with lower educational status. In smokers, MIC is often low in spite of normal UIC, presumably due to the iodine transport blocking effect of the cigarette smoke towards breast milk; normal UIC may be misinterpreted as sufficient iodine supply towards the child. Antenatal health promotion strategies should focus on young women with lower educational status, even in regions where sufficient iodine intake has been achieved in non-pregnant adults.

Associations Between Thyroid Volume and Physical Growth in Pubertal Girls: Thyroid Volume Indexes Need to Be Applied to Thyroid Volume Assessments.

BackgroundThyroid volume (Tvol) is associated with many factors, but the current reference values for Tvol in children with sufficient iodine intake are inappropriate and need to be updated. Moderate changes in thyroid morphology and accentuated increases in body fat percentage occur during puberty as an adaption of the body and sexual development occurs. This study aimed to evaluate the influences of physical growth on Tvol and propose an easily applicable method for conducting Tvol assessments in pubertal girls with sufficient iodine intake.MethodsA cohort study was conducted on 481 pubertal girls in East China from 2017 to 2019. B-ultrasound was used to assess Tvol. Multiple linear regression models were used to estimate the associations of Tvol enlargement (dTvol) with changes in height (dH), weight (dW), waist circumference (dW), body mass index (dBMI), and body surface area (dBSA). Thyroid volume indexes (TVIs), including height thyroid volume index (HVI), weight and height thyroid volume index (WHVI), body mass index thyroid index (BMIV), and body surface area thyroid index (BSAV), were calculated to explore an appropriate method for Tvol assessments by Spearman correlation analyses.ResultsTvol, height, weight, BMI, and BSA increased significantly from baseline to follow-up (P<0.001). The associations between dTvol and physical growth were only observed in the 13 to 14-year-old group. dH, dW,dBMI, and dBSA were positively related to dTvol, with the maximum β of 5.74 (95%CI: 2.54 to 8.94) on dBSA, while dWC was negatively related to dTvol (β= -0.05, 95%CI: -0.08 to -0.03). Both dHVI and dBSAV were not associated with dH, dW, dBMI, or dBSA in both age groups (P>0.05).ConclusionsThyroid volume was associated with physical growth in pubertal girls in East China, both age and anthropometric measurements must be comprehensively considered to establish the reference values for Tvol. HVI, and BSAV may be better indicators for Tvol assessments in pubertal girls.

Social and hygienic assessment of the spread of thyroid diseases

Introduction. Iodine deficiency diseases (IDD) are currently one of the most common pathologies of the endocrine system. The development of these diseases in the Primorsky region depends on the sufficient intake of iodine and various factors of exogenous and endogenous nature. The identification and establishment of the contribution of social and hygienic nature factors in the comprehensive impact to the occurrence and development of thyroid diseases, including IDD, is an important area of research. The aim of the study is to obtain information about the social and hygienic factors that influence the occurrence and development of thyroid pathology, including iodine deficiency diseases. Material and methods. Based on statistical data the dynamics in the population prevalence of diseases of the endocrine system in the Primorsky region was analyzed. To identify social and hygienic factors, a survey of 222 patients of the Center of Endocrinology Regional Clinical Hospital No. 2 (Vladivostok) was performed. Statistical processing of the results of the sociological survey was carried out using the Terentyev correlation pleiades method. Results. The development of thyroid pathology, including IDD, is influenced by unfavorable environmental conditions, physical inactivity and stressful situations in the workplace, unfavorable occupational factors including an exposure to noise, dust, radiation from a personal computer, lifestyle factors due to low physical activity, non-compliance with the waking and sleeping regime. More often, thyroid diseases develop in women and people over 50 years of age. The development of IDD is influenced by the observance of the principles of rational nutrition and the presence of certain foods in the diet. The contribution of these factors in the conditions of their combined impact on the human body is established. Conclusion. The identified complex of social and hygienic factors that are important for the occurrence and development of thyroid diseases can be further used to create targeted programs for the prevention of these diseases in the population of the Primorsky region.

Iodine in Table Salt in the Aseer Region, Southwestern Saudi Arabia

Background: Iodine, a micronutrient that plays a significant role in thyroid hormone synthesis, is essential for normal neurological development. Universal Salt Iodization is a plan advocated by the WHO to ensure sufficient iodine intake by all individuals. No accurate data was available about household coverage with iodized salt and salt iodization adequacy in the Aseer region, southwestern Saudi Arabia. Objectives: To estimate the proportion of households consuming iodized salt in the Aseer region, southwestern Saudi Arabia, and assess salt iodization’s adequacy. Methods: The study was a cross-sectional study on a stratified proportional allocation sample. The household of each child was requested to bring a teaspoonful of table salt consumed in their kitchen. The salt samples were taken in standard, small, self-sealed plastic bags. The Iodine concentration of salt was determined spectrophotometrically. Results: The study included 3038 samples of table salt. Insufficient iodized table salt samples (less than 15 ppm based on the WHO/UNICEF ICCIDD classification) were observed in 22.3% (95% CI: 20.8% – 23.8%) of the samples. Similarly, insufficient iodized table salt samples (less than 70 ppm based on Saudi Standards, Metrology and Quality Organization “SASO” classification) were observed in 75.7% (95% CI: 74.1% – 77.2%) of the study samples. The present study showed that rural areas significantly had higher insufficient table salt samples than urban areas. Conclusions: The study showed that the use of insufficient iodized salt in the region is still common. The accessibility of iodized salt can be achieved through iodized salt’s marketing and sales. Authorities in the Aseer region should play an influential role in forbidding non-iodized salt in the local markets in the Aseer region. Key words: Iodine; Table salt; Saudi Arabia

Iodine Intake in Norwegian Women and Men: The Population-Based Tromsø Study 2015-2016.

Ensuring sufficient iodine intake is a public health priority, but we lack knowledge about the status of iodine in a nationally representative population in Norway. We aimed to assess the current iodine status and intake in a Norwegian adult population. In the population-based Tromsø Study 2015–2016, 493 women and men aged 40–69 years collected 24-h urine samples and 450 participants also completed a food frequency questionnaire (FFQ). The 24-h urinary iodine concentration (UIC) was analyzed using the Sandell–Kolthoff reaction on microplates followed by colorimetric measurement. Iodine intake was estimated from the FFQ using a food and nutrient calculation system at the University of Oslo. The mean urine volume in 24 h was 1.74 L. The median daily iodine intake estimated (UIE) from 24-h UIC was 159 µg/day (133 and 174 µg/day in women and men). The median daily iodine intake estimated from FFQ was 281 µg/day (263 and 318 µg/day in women and men, respectively). Iodine intake estimated from 24-h UIC and FFQ were moderately correlated (Spearman rank correlation coefficient r = 0.39, p < 0.01). The consumption of milk and milk products, fish and fish products, and eggs were positively associated with estimated iodine intake from FFQ. In conclusion, this shows that iodine intake estimated from 24-h UIC describes a mildly iodine deficient female population, while the male population is iodine sufficient. Concurrent use of an extensive FFQ describes both sexes as iodine sufficient. Further studies, applying a dietary assessment method validated for estimating iodine intake and repeated individual urine collections, are required to determine the habitual iodine intake in this population.

Hashimoto's thyroiditis as a risk factor for thyroid cancer.

To summarize the recent developments in considering Hashimoto's thyroiditis as a risk factor for thyroid cancer. Modern approaches to understanding the co-occurrence of Hashimoto's thyroiditis and thyroid cancer have consistently found increased prevalence of both conditions, separately as well as of their coexistence. The inflammatory process in Hashimoto's thyroiditis is understood as a potential risk factor for thyroid cancer development. This has also provided a better understanding of the limitations in the current diagnostic and follow-up armamentarium for both conditions, resulting in international guidelines from the clinical and scientific societies. Other recent developments call for a paradigm shift in guidelines on thyroid carcinomas when lymphocytic infiltration is present, which potentially should always be considered the case at least in areas of sufficient iodine intake. The literature of Hashimoto's thyroiditis as a risk factor for thyroid cancer is reviewed over the last year to highlight new developments in the understanding of their association and future clinical implications.

Exploring the role of copper and selenium in the maintenance of normal thyroid function among healthy Koreans

BackgroundSelenium and iodine are trace elements well known to have important roles in the synthesis and metabolism of thyroid hormones. However, the effects of other trace elements on thyroid hormones are still inconclusive. We investigated the association between several trace elements and thyroid hormones. MethodsThe data of 448 subjects who were measured for both, trace elements and TSH/free T4, at the Heath Checkup Center were retrospectively reviewed. The presence of thyroiditis (from thyroid echogenicity) and thyroid nodules were reviewed in the subjects who underwent thyroid ultrasonography. ResultsBlood concentrations of manganese, copper, selenium, and molybdenum were associated with TSH or free T4. After adjusting for age, sex, BMI, smoking, and alcohol consumption, blood copper levels were positively associated with free T4 in both sexes and selenium levels were positively associated with free T4 in women. There was no association between trace elements and thyroiditis. Blood copper concentration had a weak non-linear association with the presence of thyroid nodules. ConclusionsThis study demonstrated that blood concentrations of copper and selenium were significantly associated with free T4 in healthy Korean subjects with sufficient iodine intake suggesting their role in maintaining normal thyroid function.

Pharmacodynamic Response to Anti-thyroid Drugs in Graves' Hyperthyroidism.

Objective: Graves' disease is the commonest cause of hyperthyroidism in populations with sufficient dietary iodine intake. Anti-thyroid drugs (ATD) are often used as the initial treatment for Graves' hyperthyroidism, however there is a paucity of data relating the dose of ATD therapy to the effect on thyroid hormone levels, increasing the risk of both over- and under-treatment. We aimed to determine the pharmacodynamic response to the ATD carbimazole.Design: Retrospective cohort study.Methods: Participants were patients (n = 441) diagnosed with Graves' disease at Imperial College Healthcare NHS Trust between 2009 and 2018. The main outcome measure was change in thyroid hormone levels in response to ATD.Results: Baseline thyroid hormone levels were positively associated with TSH receptor antibody titres (P < 0.0001). Baseline free triiodothyronine (fT3) were linearly related to free thyroxine (fT4) levels in the hyperthyroid state (fT3 = fT4*0.97–11), and fell proportionately with carbimazole. The percentage falls in fT4 and fT3 per day were associated with carbimazole dose (P < 0.0001). The magnitude of fall in thyroid hormones after the same dose of carbimazole was lower during follow up than at the initiation visit. The fall in thyroid hormone levels approximated to a linear response if assessed at least 3 weeks after commencement of carbimazole. Following withdrawal of antithyroid drug treatment, the risk of relapse was greater in patients with higher initial fT4, initial TSH receptor antibody titre, males, smokers, and British Caucasian ethnicity.Conclusion: We identify a dose-response relationship for fall in thyroid hormones in response to carbimazole to aid in the selection of dose for Graves' hyperthyroidism.

Assessment of the iodine nutritional status among Chinese school-aged children.

ObjectiveThe remarkable success of iodine deficiency disorders (IDD) elimination in China has been achieved through a mandatory universal salt iodization (USI) program. The study aims to estimate the relationship between urinary iodine concentration (UIC) and iodine content in edible salt to assess the current iodine nutritional status of school aged children.MethodsA total of 5565 students from 26 of 39 districts/counties in Chongqing participated in the study, UIC and iodine content in table salt were measured. Thyroid volumes of 3311 students were examined by ultrasound and goiter prevalence was calculated.ResultsThe overall median UIC of students was 222 μg/L (IQR: 150-313 μg/L). Median UIC was significantly different among groups with non-iodized salt (iodine content <5 mg/kg), inadequately iodized salt (between 5 and 21 mg/kg), adequately iodized (between 21 and 39 mg/kg) and excessively iodized (>39 mg/kg) salt (P < 0.01). The total goiter rate was 1.9% (60/3111) and 6.0% (186/3111) according to Chinese national and WHO reference values, respectively. Thyroid volume and goiter prevalence were not different within the three iodine nutritional status groups (insufficient, adequate and excessive, P > 0.05).ConclusionsThe efficient implementation of current USI program is able to reduce the goiter prevalence in Chongqing as a low incidence of goiter in school aged children is observed in this study. The widened UIC range of 100–299 μg/L indicating sufficient iodine intake is considered safe with a slim chance of causing goiter or thyroid dysfunction. Further researches were needed to evaluate the applicability of WHO reference in goiter diagnose in Chongqing or identifying more accurate criteria of normal thyroid volume of local students in the future.

The effect of additive containing an organic form of iodine on the physiological-biochemical parameters of the body of cows

Iodine deficiency in soil and water in many countries leads to its low content in plants and animal feed produced from them. The limited intake of this element in animals can lead to endemic diseases. The lack of iodine in animal feeding is most often compensated for by the use of additives with an inorganic form of iodine, which can be poorly absorbed by the body. Feed products with an organic form of iodine have a great biological effect. A study on the effect of iodine-containing additives on the physiological and biochemical parameters of the animal organism was carried out on two groups of 15 cows. The experimental group was fed an organic form of iodine as part of the additive, the control group received an inorganic form of iodine. For all animals during the experiment the biochemical parameters of blood, milk productivity and reproductive ability were studied. During the experiment, an increase in metabolic and redox processes in the body was noted in the experimental group. An increase in mineral metabolism, including iodine content, was found. Due to the sufficient intake of organic iodine in the animals of the experimental group, there was an increase in the activity of the main hepatic enzymes AST and ALT. An increase in the process of gluconeogenesis due to an increase in the glucose content in the blood of experimental cows was revealed. An increase in milk production and reproductive function of animals of the experimental group was established. Within 30 days after the termination of feeding the supplement with the organic form of iodine in the experimental group, a prolonging effect was observed, consisting in higher values of blood biochemical parameters, improved reproductive function and milk productivity relative to equivalent animals in the control. As a result, it was concluded that the use of an additive with an organic form of iodine in the amount of 1.5 g in feeding cows for 60 days increases the iodine content in the blood serum of animals and increases the performance of all types of metabolism, which may indicate the best stimulating effect of the organic form of iodine on thyroid activity glands. This in turn helps to improve the productive and reproductive qualities of animals. To recommend the studied drug as a means to replenish iodine deficiency in animals and to more accurately analyze its effect on the hormone-forming function of the thyroid gland, it is necessary to study the level of thyroid hormones in the blood.

Impaired Gene Expression Due to Iodine Excess in the Development and Differentiation of Endoderm and Thyroid Is Associated with Epigenetic Changes.

Background: Thyroid hormone (TH) synthesis is essential for the control of development, growth, and metabolism in vertebrates and depends on a sufficient dietary iodine intake. Importantly, both iodine deficiency and iodine excess (IE) impair TH synthesis, causing serious health problems especially during fetal/neonatal development. While it is known that IE disrupts thyroid function by inhibiting thyroid gene expression, its effects on thyroid development are less clear. Accordingly, this study sought to investigate the effects of IE during the embryonic development/differentiation of endoderm and the thyroid gland. Methods: We used the murine embryonic stem (ES) cell model of in vitro directed differentiation to assess the impact of IE on the generation of endoderm and thyroid cells. Additionally, we subjected endoderm and thyroid explants obtained during early gestation to IE and evaluated gene and protein expression of endodermal markers in both models. Results: ES cells were successfully differentiated into endoderm cells and, subsequently, into thyrocytes expressing the specific thyroid markers Tshr, Slc5a5, Tpo, and Tg. IE exposure decreased the messenger RNA (mRNA) levels of the main endoderm markers Afp, Crcx4, Foxa1, Foxa2, and Sox17 in both ES cell-derived endoderm cells and embryonic explants. Interestingly, IE also decreased the expression of the main thyroid markers in ES cell-derived thyrocytes and thyroid explants. Finally, we demonstrate that DNA methyltransferase expression was increased by exposure to IE, and this was accompanied by hypermethylation and hypoacetylation of histone H3, pointing to an association between the gene repression triggered by IE and the observed epigenetic changes. Conclusions: These data establish that IE treatment is deleterious for embryonic endoderm and thyroid gene expression.

Iodine and Myo-Inositol: A Novel Promising Combination for Iodine Deficiency.

Despite universal salt iodization programmes implemented over the last decades, iodine deficiency remains a major public health problem in many countries worldwide. Endeavors are still required to ensure sufficient iodine intake in the populations at risk in order to eliminate deficiency. Iodine is crucial for the synthesis of thyroid hormones triiodothyronine (T3) and thyroxine (T4), as well as for the thyroid health. When iodine levels are insufficient, T4 attests toward the lower limit of the physiological range, causing subtle fluctuations in the T3:T4 ratio. Monitoring these variations may be an accurate way to assess patient's iodine status. Recently, a number of published clinical studies documented a growing interest toward the use of myo-inositol in thyroid diseases. Myo-inositol, a carbocyclic polyol, regulates the generation of hydrogen peroxide (H2O2) in thyrocytes, crucial for iodine organification and thyroid hormone biosynthesis. Thus, combined supplementation of iodine and myo-inositol may promote higher iodine availability in thyrocytes improving thyroid functionality. This review presents novel strategies for the diagnosis and the management of iodine deficiency, focusing on the potential role of myo-inositol combined with iodine.