Iodine Supplementation Research Articles

Iodine status in pregnant women in northern Spain. Effect of iodised salt and iodine supplements on thyroid function

IntroductionIodine deficiency is linked to thyroid dysfunction, particularly in pregnant women. The objective of this study was to ascertain the iodine levels of women in the second trimester of pregnancy, analysing the influence of iodine ingestion on urinary iodine concentration (UIC) and maternal thyroid function. MethodsA prospective observational study of pregnant women from Health Area IV of Asturias (northern Spain) recruited before 13 weeks of gestation between May and June 2017. A questionnaire on iodine intake was completed at the first visit, and urine and serum samples were collected at baseline and again during the second trimester. UIC, thyroid stimulating hormone (TSH) and free thyroxine (FT4) obtained in the second trimester of gestation were analysed and related to iodine intake. Thyroid autoimmunity was also analysed in half of the pregnant women at baseline. ResultsA total of 241 pregnant women were studied. Of these, 56.7% used iodised salt, 46.7% consumed ≥2 servings of dairy products daily and 88.1% took iodine supplements. Median UIC was 191μg/l (135.3–294μg/l), with 68.1% of the women having UIC ≥150μg/l. Only iodised salt consumption provided protection against iodine deficiency (odds ratio 0.35 [0.20–0.63], p=0.001). In women with no autoimmune thyroid disease (n=88), mean levels of TSH were lower in those that consumed iodised salt than in those that did not (respectively, 2.08±0.89mIU/l vs. 2.56±1.02mIU/l, p=0.025). In women with autoimmune thyroid disease (n=30), mean levels of TSH were higher in those that took iodine supplements than in those that did not (respectively, 2.97±1.25mIU/l vs. 1.16±0.41mIU/l, p=0.002). ConclusionsThe pregnant women studied from Health Area IV in Asturias maintain adequate nutritional iodine status in the second trimester of gestation. In our sample, only the consumption of iodised salt was associated with adequate iodine nutrition, without affecting maternal thyroid function. Most of the women used iodine supplements, which was linked to higher levels of TSH in pregnant women with autoimmune thyroid disease.

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.

Iodine Deficiency and Iodine Prophylaxis: An Overview and Update.

The thyroid gland requires iodine to synthesize thyroid hormones, and iodine deficiency results in the inadequate production of thyroxine and related thyroid, metabolic, developmental, and reproductive disorders. Iodine requirements are higher in infants, children, and during pregnancy and lactation than in adult men and non-pregnant women. Iodine is available in a wide range of foods and water and is susceptible to almost complete gastric and duodenal absorption as an iodide ion. A healthy diet usually provides a daily iodine consumption not exceeding 50% of the recommended intake. Iodine supplementation is usually necessary to prevent iodine deficiency disorders (IDDs), especially in endemic areas. The community-based strategy of iodine fortification in salt has eradicated IDDs, such as endemic goiter and cretinism, in countries providing adequate measures of iodine prophylaxis over several decades in the 20th century. Iodized salt is the cornerstone of iodine prophylaxis in endemic areas, and the continuous monitoring of community iodine intake and its related clinical outcomes is essential. Despite the relevant improvement in clinical outcomes, subclinical iodine deficiency persists even in Western Europe, especially among girls and women, being an issue in certain physiological conditions, such as pregnancy and lactation, and in people consuming unbalanced vegetable-based or salt-restricted diets. Detailed strategies to implement iodine intake (supplementation) could be considered for specific population groups when iodized salt alone is insufficient to provide adequate requirements.

Obesity in Pregnancy: A Comprehensive Review of Influential Guidelines.

Obesity is one of the most common clinical entities complicating pregnancies and is associated with short- and long-term consequences for both the mother and the offspring. The aim of this study were to review and compare the most recently published influential guidelines on the management of maternal obesity in the preconceptional, antenatal, intrapartum, and postpartum period. A descriptive review of guidelines from the American College of Obstetricians and Gynecologists, the International Federation of Gynecology and Obstetrics, the Society of Obstetricians and Gynecologists of Canada, the Royal College of Obstetricians and Gynecologists, and the Royal Australian and New Zealand College of Obstetricians and Gynecologists on obesity in pregnancy was carried out. There is an overall agreement among the reviewed guidelines regarding the importance of prepregnancy weight loss with behavioral modification, optimization of gestational weight gain, and screening for comorbidities in improving pregnancy outcomes of obese women. Women with previous bariatric surgery should be screened for nutritional deficiencies and have a closer antenatal surveillance, according to all guidelines. In addition, folic acid supplementation is recommended for 1 to 3 months before conception and during the first trimester, but several discrepancies were identified with regard to other vitamins, iodine, calcium, and iron supplementation. All medical societies recommend early screening for gestational diabetes mellitus and early anesthetic assessment in obese women and suggest the use of aspirin for the prevention of preeclampsia when additional risk factors are present, although the optimal dosage is controversial. The International Federation of Gynecology and Obstetrics, Society of Obstetricians and Gynecologists of Canada, Royal College of Obstetricians and Gynecologists, and Royal Australian and New Zealand College of Obstetricians and Gynecologists point out that specific equipment and adequate resources must be readily available in all health care facilities managing obese pregnant women. Moreover, thromboprophylaxis and prophylactic antibiotics are indicated in case of cesarean delivery, and intrapartum fetal monitoring is justified during active labor in obese patients. However, there are no consistent protocols regarding the fetal surveillance, the monitoring of multiple gestations, the timing and mode of delivery, and the postpartum follow-up, although weight loss and breastfeeding are unanimously supported. Obesity in pregnancy is a significant contributor to maternal and perinatal morbidity with a constantly rising global prevalence among reproductive-aged women. Thus, the development of uniform international protocols for the effective management of obese women is of paramount importance to safely guide clinical practice and subsequently improve pregnancy outcomes.

Maternal iodine intake and adherence to iodine supplement recommendations in a group of Chinese women: the results from the WIN cohort study

Maternal iodine intake and adherence to iodine supplement recommendations in a group of Chinese women: the results from the WIN cohort study

Impact of iodine intake on the pathogenesis of autoimmune thyroid disease in children and adults.

Thyroid hormone (TH) regulates the body's metabolism and iodine, a vital trace mineral, is vital for TH synthesis. As a TH biosynthesis catalyst, iodine has a substantial role in our health. When there is a modest iodine deficit, the thyroid gland grows autonomously, resulting in thyrotoxicosis. Those who consume excessive iodine risk developing hypothyroidism and thyroid autoimmunity. A transient hyperthyroid condition may rapidly increase iodine consumption. Iodine deficiency is common across the globe, and provision of supplementary iodine, in forms such as iodized salt or vegetable oil, has many benefits. Vegetarians, for instance, may not consume adequate amounts of iodine in some countries with high iodine content. Reduced dietary iodine intakes may be a consequence of efforts to reduce salt intakes to prevent hypertension. In addition, iodine consumption is decreasing in many countries, even among those where endemic goiter has previously been eradicated, leading to the re-emergence of iodine-deficiency-related disorders such as goiter. This review will discuss how iodine can contribute to the development of thyroid disease.

Lead acetate as a superior lead source enables highly efficient and stable all-inorganic lead-tin perovskite solar cells

All-inorganic lead–tin (Pb-Sn) perovskite solar cells (PSCs) offer a promising alternative for the conventional organolead halide hybrid perovskite-based photovoltaic, and lead iodide (PbI2) has been commonly used as the lead source for Pb-Sn PSCs, however it is hard to obtain phase-pure CsPbxSn1-xX3 (X = I, Br) perovskite films with specific composition. Herein, lead acetate (Pb(Ac)2) was applied as an alternative lead source substituting PbI2 along with addition of methylamine iodide (MAI) as a supplementary iodine source, affording homogeneous phase-pure CsPb0.4Sn0.6I2.4Br0.6 perovskite film. Pb(Ac)2 has comparable Pb2+ release rate to that of Sn2+ from SnI2, preventing from inhomogeneous crystallization process. Pb(Ac)2 lead source further helps to suppress the nonradiative recombination, reduce trap states, and improve interfacial charge transport, leading to dramatic PCE enhancement. As a result, the inverted-structure CsPb0.4Sn0.6I2.4Br0.6 PSC device based on Pb(Ac)2 lead source delivers a certified power conversion efficiency (PCE) of 13.88 %, which is the highest value among all-inorganic Pb-Sn PSCs reported up to now. Pb(Ac)2 lead source further benefits simultaneous improvements of the thermal and operational stabilities of PSC devices.

Iodine supplementation through its biofortification in Brassica species depending on the type of soil.

Iodine is an essential microelement for humans and its deficiency leads to iodine deficiency disorder (IDD) which is a common problem faced by people in hilly areas. Biofortification of iodine is an option to overcome the IDD problem. Herein, we investigated the iodine uptake and accumulation in the edible portion of vegetables such as Brassica napus (BNP) and Brassica pekinensis (BPK) which were grown on two different soils such as sandy soil (SS) and silty loam soil (SLS) with different concentrations of iodine application (used in sodium iodide form) such as 0ppm, 50ppm, and 100ppm. The concentration of iodine was determined by the oxidation of iodide, and nutrients were examined by double acid digestion. Different concentrations of iodine were noticed in silty loam and sandy soils, roots, and shoots of BNP and BPK, while the concentration follows the order: soils > roots > shoots. Iodine concentrations in the roots of BNP and BPK ranged from 46 to 223.7μg/g which shows a strong correlation with other soil nutrients. Moreover, a large amount of iodine was lost due to the leaching. It is concluded that the biofortification of iodine increases its concentration in Brassica species. This work provides a reference for the iodine biofortification in plant species which will be helpful to control IDD.

Sustained Elimination of Iodine Deficiency Within the Third Decade After Compulsory Iodine Supplementation Policy in the South of Iran: A Population-Based Cross-Sectional Study

ObjectivesRecently, some studies in Iran have shown mild to moderate iodine concentrations in adult and pregnant women populations despite iodine sufficiency in children. This study aimed to evaluate the urine iodine status and salt intake among adult households in the city of Sadra, Fars province in southern Iran, and to assess its possible influencing factors. MethodParticipant households for this cross-sectional study were selected using randomized cluster sampling in the city of Sadra, Fars province, southern Iran from 1 February, 2021 to 30 November, 2021. Two subjects >18 y of age from each household were invited. Ninety-two subjects (24 men, 68 women) were enrolled. The participants were asked to collect their 24 h urine. They were then examined for thyroid disorders and subjected to thyroid ultrasonography and thyroid function tests. Urine samples were tested for iodine, sodium, and creatinine concentrations. Household salt intake was also estimated. ResultsMedian urine iodine content (UIC) in the participants was 175 (IQR: 117, 250) μg/L, whereas the median salt consumption per person per day was 9.6 (IQR, 7.3-14.5) g. Sex, methods of salt storage, presence of goiter or thyroid nodules, the addition of salt in the cooking stage, and subclinical hypothyroidism had no effect on UIC, whereas individuals with hypertension and lower education had significantly lower iodine concentrations. UIC had a significant positive correlation with urine sodium and thyroid stimulating hormones (TSH) concentrations (P < 0.001, 0.046) and a negative correlation with thyroid volume and T4 (P = 0.029, 0.018). ConclusionIodine status in the adult population of Sadra city was categorized as sufficient, although the iodine concentrations reported in Tehran were insufficient. The contributing factor can be higher salt consumption or possible higher environmental iodine concentrations in Sadra city than Tehran.

Serum lipid profile in relation to free thyroxine and the effect of levothyroxine treatment on lipids in patients with isolated hypothyroxinemia during pregnancy: a single-center retrospective study

BackgroundThyroid function is widely considered a lipid metabolism regulator. However, studies on lipid metabolism in pregnant women with low free thyroxine (FT4) levels are limited and inconclusive. Furthermore, the association between maternal FT4 deficiency and adverse lipid metabolic parameters is unknown. Therefore, we aimed to investigate this association and the effects of levothyroxine (L-T4) treatment on these metabolic indicators.MethodsThis retrospective study included 164 patients with isolated hypothyroidism (IH) (FT4 levels below the 5th percentile with normal thyroid stimulating hormone levels according to the gestational-specific reference range) and 407 euthyroidism patients (control group who had regular antenatal examinations at Zhejiang Provincial People's Hospital, Hangzhou, China) between January 1, 2019, and December 31, 2020. Patients with IH were divided into levothyroxine (L-treatment group, n = 77) and dietary iodine supplement treatment groups (dietary treatment group, n=87) according to the hospital’s treatment policy and clinical experience. The intervention lasted for at least 8 weeks. Metabolic indicators, including thyroid function and lipid parameters, were collected at least twice before and after the intervention. Other data collected included maternal age, history of abortion, prepregnancy BMI, and gestational weight gain (Fig. 1).ResultsCompared with the control group, Patients with IH had a higher degree of dyslipidemia, reflected in elevated total cholesterol (TC), triglycerides (TG), low-density lipoprotein cholesterol (LDL-C), and apolipoprotein B (Apo B) levels. In IH patients, an inverse correlation was found between FT4 and TG levels, which remained after adjusting for prepregnancy BMI. The L-treatment group demonstrated a significantly slower rate of hypercholesterolemia progression during pregnancy than the dietary treatment group. In addition, there was a relationship between the therapeutic effect and the degree of disease, with the main factors being FT4, TSH and TG levels prior to starting treatment.ConclusionsLow FT4 levels were associated with elevated blood lipid levels. Serum FT4 and lipid levels in patients could be improved by medical intervention.

Iodine status in pregnant women in northern Spain. Effect of iodised salt and iodine supplements on thyroid function

IntroductionIodine deficiency is linked to thyroid dysfunction, particularly in pregnant women. The objective of this study was to ascertain the iodine levels of women in the second trimester of pregnancy, analysing the influence of iodine ingestion on urinary iodine concentration (UIC) and maternal thyroid function. MethodsA prospective observational study of pregnant women from Health Area IV of Asturias (northern Spain) recruited before 13 weeks of gestation between May and June 2017. A questionnaire on iodine intake was completed at the first visit, and urine and serum samples were collected at baseline and again during the second trimester. UIC, thyroid stimulating hormone (TSH) and free thyroxine (FT4) obtained in the second trimester of gestation were analysed and related to iodine intake. Thyroid autoimmunity was also analysed in half of the pregnant women at baseline. ResultsA total of 241 pregnant women were studied. Of these, 56.7% used iodised salt, 46.7% consumed ≥2 servings of dairy products daily and 88.1% took iodine supplements. Median UIC was 191μg/l (135.3–294μg/l), with 68.1% of the women having UIC ≥150μg/l. Only iodised salt consumption provided protection against iodine deficiency (odds ratio 0.35 [0.20–0.63], p=0.001). In women with no autoimmune thyroid disease (n=88), mean levels of TSH were lower in those that consumed iodised salt than in those that did not (respectively, 2.08±0.89mIU/l vs. 2.56±1.02mIU/l, p=0.025). In women with autoimmune thyroid disease (n=30), mean levels of TSH were higher in those that took iodine supplements than in those that did not (respectively, 2.97±1.25mIU/l vs. 1.16±0.41mIU/l, p=0.002). ConclusionsThe pregnant women studied from Health Area IV in Asturias maintain adequate nutritional iodine status in the second trimester of gestation. In our sample, only the consumption of iodised salt was associated with adequate iodine nutrition, without affecting maternal thyroid function. Most of the women used iodine supplements, which was linked to higher levels of TSH in pregnant women with autoimmune thyroid disease.

Dietary Supplement Intake and Fecundability in a Singapore Preconception Cohort Study

Subfertility is a global problem affecting millions worldwide, with declining total fertility rates. Preconception dietary supplementation may improve fecundability, but the magnitude of impact remains unclear. This prospective cohort study aimed to examine the association of preconception micronutrient supplements with fecundability, measured by time to pregnancy (TTP). The study was conducted at KK Women's and Children's Hospital, Singapore, between February 2015 and October 2017, on 908 women aged 18-45 years old, who were trying to conceive and were enrolled in the Singapore PREconception Study of long-Term maternal and child Outcomes (S-PRESTO). Baseline sociodemographic characteristics and supplement intake were collected through face-to-face interviews. The fecundability ratio (FR) was estimated using discrete-time proportional hazard modelling. Adjusting for potentially confounding variables, folic acid (FA) (FR 1.26, 95% confidence interval 1.03-1.56) and iodine (1.28, 1.00-1.65) supplement users had higher fecundability compared to non-users. Conversely, evening primrose oil supplement users had lower fecundability (0.56, 0.31-0.99) than non-users. In this study, preconception FA and iodine supplementation were associated with shortened TTP, while evening primrose oil use was associated with longer TTP. Nonetheless, the association between supplement use and the magnitude of fecundability changes will need to be further confirmed with well-designed randomised controlled trials.

Iodine contrast exposure and incident COVID-19 infection.

Iodine and particularly its oxidated forms have long been recognized for its effective antiseptic properties. Limited in vitro and in vivo data suggest that iodine exposure may rapidly inactivate, reduce transmission, and reduce infectivity of SARS-CoV-2. We hypothesized that iodine exposure may be associated with decreased incident COVID-19 infection. A retrospective population-level cohort analysis was performed of the U.S. Veterans Health Administration between 1 March 2020 and 31 December 2020, before the widespread availability of vaccines against SARS-CoV-2. Multivariable logistic regression models estimated the adjusted odds ratios (OR) and 95% confidence intervals (CI) of the associations between iodinated contrast exposure and incident COVID-19 infection, adjusting for age, sex, race/ethnicity, place of residence, socioeconomic status, and insurance status. 530,942 COVID-19 tests from 333,841 Veterans (mean ± SD age, 62.7 ± 15.2 years; 90.2% men; 61.9% non-Hispanic Whites) were analyzed, of whom 9% had received iodinated contrast ≤60 days of a COVID-19 test. Iodine exposure was associated with decreased incident COVID-19 test positivity (OR, 0.75 95% CI, 0.71-0.78). In stratified analyses, the associations between iodinated contrast use and decreased COVID-19 infection risk did not differ by age, sex, and race/ethnicity. Iodine exposure may be protective against incident COVID-19 infection. Weighed against the risks of supraphysiologic iodine intake, dietary, and supplemental iodine nutrition not to exceed its Tolerable Upper Limit may confer an antimicrobial benefit against SARS-CoV-2. A safe but antimicrobial level of iodine supplementation may be considered in susceptible individuals, particularly in geographic regions where effective COVID-19 vaccines are not yet readily available.

Evaluation of Iodine Supplementation in Pregnant Women with Gestational Diabetes: IODIAB Study.

Iodine supplementation is indicated by the French National Authority for Health (HAS) and the World Health Organization (WHO) during pregnancy. This study investigates whether this supplementation is consistently prescribed in line with WHO recommendations in pregnant women diagnosed with gestational diabetes mellitus. A total of 99 women with a diagnosis of gestational diabetes were included in the study and were all closely monitored. Only 17 (17.2%) patients received the recommended iodine supplementation. The follow-up, whether conducted by a gynecologist or midwife, did not influence the prescription of iodine supplements. By contrast, 72 (72.7%) of patients received folic acid supplementation. The prescription of iodine supplementation for the pregnant women included in our study is insufficient. Few practitioners seem aware of the recommendations, even when the pregnancy is complicated by gestational diabetes.

Prevalence and Predictors of Low Breast Milk Iodine Concentration in Women Following Vegan, Vegetarian, and Omnivore Diets.

Purpose: Breast milk iodine concentration (BMIC) from vegan and vegetarian lactating mothers has not previously been evaluated. The goal of this study was to assess BMIC from vegans, vegetarians, and omnivores and to assess intake of iodine by breastfed infants. Materials and Methods: Breast milk samples from vegans (n = 12), vegetarians (n = 6), and omnivores (n = 12) living in the United States were analyzed. BMIC was determined at the mass-to-charge ratio (m/z) 127 by inductively coupled plasma mass spectrometry (ICP-MS) using an Agilent 8800 ICP-MS/MS (Agilent Technologies). Results: There was a significant difference in mean BMIC between participants following a plant-based diet (vegan and vegetarian, n = 18) compared with omnivores [4.42 versus 5.02 Ln(BMIC), respectively; p = 0.0405]. In linear regression to predict BMIC, vegan diet was a negative predictor (standardized β = -0.409) and use of multi- or prenatal supplements was a positive predictor (standardized β = 0.319). There were differences in the percentage of inadequate BMIC per maternal diet (75% vegan, 67% vegetarian, omnivore 58%) but this did not reach statistical significance. In 67% of the samples (20/30) BMIC was lower than the National Academy of Medicine's adequate intake (AI), assuming infant milk consumption of 0.78 L/day. Conclusions: Most samples from vegans and vegetarians contained a lower BMIC than AI for infants 0-6 months. Counseling of pregnant vegans and vegetarians should highlight importance of iodine supplementation during lactation. The findings are based on a small number of samples, especially for vegetarians, and thus, they need to be confirmed by larger studies.

Current Strategies for Selenium and Iodine Biofortification in Crop Plants.

Selenium and iodine are essential trace elements for both humans and animals. Among other things, they have an essential role in thyroid function and the production of important hormones by the thyroid gland. Unfortunately, in many areas, soils are deficient in selenium and iodine, and their amount is insufficient to produce crops with adequate contents to cover the recommended daily intake; thus, deficiencies have an endemic character. With the introduction of iodized table salt in the food industry, the thyroid status of the population has improved, but several areas remain iodine deficient. Furthermore, due to the strong relationship between iodine and selenium in metabolic processes, selenium deficiency often compromises the desired positive impact of salt iodization efforts. Therefore, a considerable number of studies have looked for alternative methods for the simultaneous supplementation of selenium and iodine in foodstuff. In most cases, the subject of these studies is crops; recently, meat has also been a subject of interest. This paper reviews the most recent strategies in agriculture to fortify selenium and iodine in crop plants, their effect on the quality of the plant species used, and the potential impact of food processing on their stability in fortified crops.

PSAT330 Excess Iodine Intake From a Cystic Fibrosis Supplement Induces Symptomatic Hypothyroidism

Abstract A 45-year-old woman with cystic fibrosis (delF508/delF508), pancreatic exocrine insufficiency, and diet-controlled cystic fibrosis-related diabetes presented with new complaints of dry skin, hair loss, and cold intolerance. She had no personal or family history of thyroid disease. Physical exam was notable for a mildly enlarged, non-tender thyroid gland without nodules, and 2+ bicep reflexes with delayed relaxation phase. Labs revealed a TSH of 17 mcIU/mL (n 0.3-4.20 mcIU/mL), free T4 of 0.6 ng/dL (n 0.9-1.7 ng/dL), and a thyroid peroxidase antibody of 15 units/mL (n 0-34 units/mL), consistent with new onset, overt hypothyroidism. Thyroid ultrasound revealed a hypervascular, heterogeneous gland, suggestive of underlying autoimmune thyroid disease. Given such an abrupt and significant change in previously normal thyroid studies, further history was obtained. The patient disclosed taking TauriNac, a supplement discovered online that is believed to help clear heavy metals, which she believed she was exposed to via IV antibiotics, and for treatment of her cystic fibrosis. The patient was taking 3-4 packets of TauriNac per day, totaling 16,000 mcg of potassium iodide, far exceeding the Recommended Dietary Allowance of 150 mcg per day. She discontinued TauriNac and one month later, thyroid function tests normalized. The patient then resumed TauriNac, 2-3 packets per day, and within five months TSH rose to 9.66 mcIU/mL with free T4 0.9 ng/dL. She again stopped taking TauriNac and two months after discontinuation thyroid levels normalized. Later, after yet again resuming TauriNac, 5 packets per week, her TSH increased to 4.71 mcIU/mL. She subsequently discontinued TauriNac with normalization of her TSH after three months. Over one year later, she remains off TauriNac and is clinically and biochemically euthyroid. In the 1970s, development of a goiter and hypothyroidism was reported in CF patients, especially those treated with iodine-based expectorants, raising concern for underlying thyroid dysfunction in CF; however the true prevalence of underlying thyroid dysfunction in CF patients is controversial. A 2016 United States-based study of CF patients revealed abnormal thyroid function tests in 27%, however the abnormalities were mild, and overt thyroid dysfunction was rare. In our center's experience, transient subclinical hypothyroidism associated with CF exacerbations is common and may correlate with poor dietary intake leading to iodine deficiency. In this case, excessive iodide intake via TauriNAC clearly correlated with the development of symptomatic hypothyroidism, presumably due to failure to escape the Wolff-Chaikoff effect. In a 2002 survey of adult CF patients, 70% reported having taken complementary and alternative medicine (CAM) in the past. The high prevalence of CAM use in the CF population as well as prior studies demonstrating iodine induced hypothyroidism in CF patients should inform providers of the potential harmful effects of iodine supplementation in an iodine-replete population. Presentation: Saturday, June 11, 2022 1:00 p.m. - 3:00 p.m.

The prevalence of insufficient iodine intake in pregnancy in Africa: a systematic review and meta-analysis

BackgroundFortification of foodstuffs with iodine, mainly through iodization of salt, which commenced in several African countries after 1995 is the main method for mitigating iodine deficiency in Africa. We assessed the degree of iodine nutrition in pregnancy across Africa before and after the implementation of national iodine fortification programs (CRD42018099434).MethodsElectronic databases and gray literature were searched for baseline data before implementation of population-based iodine supplementation and for follow-up data up to September 2020. R-metamedian and metamean packages were used to pool country-specific median urinary iodine concentration (UIC) estimates and derived mean UIC from studies with similar features.ResultsOf 54 African countries, 23 had data on iodine nutrition in pregnancy mostly from subnational samples. Data before 1995 showed that severe iodine deficiency was prevalent in pregnancy with a pooled pregnancy median UIC of 28.6 μg/L (95% CI 7.6–49.5). By 2005, five studies revealed a trend towards improvement in iodine nutrition state in pregnancy with a pooled pregnancy median UIC of 174.1 μg/L (95% CI 90.4–257.7). Between 2005 and 2020 increased numbers of national and subnational studies revealed that few African countries had sufficient, while most had mildly inadequate, and some severely inadequate iodine nutrition in pregnancy. The pooled pregnancy median UIC was 145 μg/L (95% CI 126–172).ConclusionImprovement in iodine nutrition status in pregnancy following the introduction of fortification of foodstuffs with iodine in Africa is sub-optimal, exposing a large proportion of pregnant women to the risk of iodine deficiency and associated disorders.Systematic review registrationPROSPERO CRD42018099434

Association between Elevated Iodine Intake and IQ among School Children in Portugal.

The goal of this work was to examine whether elevated iodine intake was associated with adverse effects on IQ among school-age children in Portugal. In a representative sample of children from the north of the country, IQ percentiles by age (assessed with Raven's Colored Progressive Matrices) were dichotomized to &lt;50 ("below-average" IQs) and ≥50. Morning urine iodine concentrations, corrected for creatinine, were dichotomized to &lt;250 µg/g and ≥250 µg/g, according to the European Commission/Scientific Committee on Food's tolerable upper level of daily iodine intake for young children. Data were examined with Chi-square tests, logistic regression, and GLM univariate analysis. The sample (N = 1965) was classified as generally iodine-adequate (median urinary iodine concentration = 129 µg/L; median iodine-to-creatinine ratio = 126 µg/g) according to the WHO's criteria. A greater proportion of children in the ≥250 µg/g group had below-average IQs, compared to children with less than 250 µg/g (p = 0.037), despite a sizable (though non-significant) proportion of children in the less-than-250 µg/g group also presenting below-average IQs, at the bottom of the iodine distribution (&lt;50 µg/g). The proportion of below-average IQs increased with increasingly elevated iodine concentrations (p = 0.047). The association remained significant after the adjustment for confounders, with the elevated iodine group showing increased odds of having below-average IQs when compared with the non-elevated iodine group (OR 1.55; 95% CI 1.11-2.17; p = 0.011). Consistently, the former group presented a lower mean IQ than the latter (p = 0.006). High iodine intake was associated with lower IQs even in a population classified as iodine-adequate. These results bear on child cognition and on initiatives involving iodine supplementation.

Nutritional Status of Iodine in a Group of Pregnant Women from the State of Minas Gerais Correlated with Neonatal Thyroid Function.

To evaluate the iodine sufficiency of pregnant women assisted in a University Hospital of Minas Gerais, and to correlate the urinary concentrations of maternal iodine with the fetal thyroid hormone levels at birth. Urinary iodine concentrations from 30 pregnant women with a singleton pregnancy and gestational age lower than 20 weeks were analyzed. Occasional samples of the mothers' urine were collected for the urinary iodine concentration dosage, and these were correlated with the newborns' thyroid-stimulating hormone (TSH) levels. The median iodine urinary concentration of this study's pregnant women population was 216.73 mcg/l, which is proper for the group, following the World Health Organization (WHO). No cases of neonatal hypothyroidism were reported in the study, which corroborates the iodine sufficiency in this population sample. This study shows that despite the increased demand for iodine from pregnant women and the Brazilian Health Regulatory Agency (ANVISA) recommendation of 2013 for reduction of salt iodization levels, the population of pregnant women attended in the prenatal ambulatory of normal risk from the Federal University of Minas Gerais is considered sufficient in iodine. As a higher sample is necessary for the confirmation of these findings, it is too early to recommend the universal supplementation of iodine for Brazilian pregnant women, and more studies must be carried out, considering that iodine supplementation for pregnant women in an area of iodine sufficiency is associated to the risks of the fetus's excessive exposure to iodine.