Variability and Seasonal Change of Urinary Selenium, Molybdenum, and Iodine Excretion in Healthy Young Japanese Adults.

Selenium (Se), molybdenum (Mo), and iodine (I) are essential trace elements or nutrients and their adequate intake is essential for human health. These elements in foods are easily absorbed from the digestive tract and excreted predominantly into the urine, and their nutritional status is reflected in urinary excretion; however, information on the variability of urinary excretion is limited. To characterize the urinary Se, Mo, and I concentrations and their intra- and inter-individual coefficients of variation (CV), correlation, and seasonal change, spot urine samples were collected from 24 healthy university students, 10 males and 14 females, with the mean age of 20.

Iodine Metabolism and Thyroid Function During the Perinatal Period: Maternal-Neonatal Correlation and Effects of Topical Povidone-Iodine Skin Disinfectants.

An adequate maternal iodine intake during pregnancy and lactation is essential for growth and mental development in fetuses and newborns. There are limited data on perinatal iodine metabolism in mothers and infants, as well as the effect of povidone-iodine (PVP-I) antiseptics used in cesarean delivery. The urinary iodine concentration (UIC), serum iodine, thyrotropin (TSH), free thyroxine (FT4), and breast milk iodine concentration (BMIC) were measured consecutively in a total of 327 mothers and 249 term-infants in two prospective studies.

Gestational trimester-specific reference ranges for serum thyrotropin and free thyroxine in Japanese.

Thyroid diseases in pregnant and lactating women may result in adverse outcomes for both mothers and infants. A reference range for thyroid function is required in different areas; however, few studies on the gestational change or reference ranges of thyrotropin (TSH) and free thyroxine (FT4) concentrations for Japanese pregnant women have been reported. To establish the gestational trimester-specific reference ranges of serum TSH and FT4 concentrations, our previously published data on 481 pregnant women with the mean age of 30.

Current Iodine Status in Japan: A Cross-sectional Nationwide Survey of Schoolchildren, 2014-2019.

Context: Japan has been regarded as a long-standing iodine-sufficient country without iodine fortification; however, data on nationwide iodine status are lacking.

Objective: This study aimed to characterize the iodine status in Japan.

Methods: From 2014 through 2019, a nationwide school-based survey was conducted across all districts in Japan.

Studies on urinary excretion and variability of dietary iodine in healthy Japanese adults.

The daily consumption of iodine in Japan is higher than in most countries, and there are few reports on iodine metabolism and variance of habitual iodine ingestion in an iodine-sufficient area. To elucidate the patterns of short-term urinary iodine excretion (UIE) and long-term variability of habitual iodine intake, the urinary iodine excretion process after a high dietary iodine load of 3 mg was observed in eight Japanese adults under strict supervision with complete urine collections for three days. In addition, estimated UIE and dietary iodine intake (DII) were assessed in 24 university students using repeated spot urine samples of ten consecutive days and a food frequency questionnaire in each of the four seasons.

High Ingestion Rate of Iodine from Povidone-Iodine Mouthwash.

Iodine-based mouthwash and throat sprays contain povidone iodine (PVP-I) for disinfection. PVP-I mouthwash has been commonly used for decades in Japan and other countries and frequent and/or prolonged use of PVP-I mouthwash can induce transient hypothyroidism. To assess the amount of iodine ingested from an oral rinse, 22 healthy adult volunteers (mean age: 48.

Iodine intake in healthy Japanese aged from 6 to 70 years residing in the same district.

Iodine is an essential component of thyroid hormones and a dietary micronutrient for humans, and adequate iodine intake is necessary to maintain thyroid function. A population's iodine intake and nutritional status are assessed based on urinary iodine excretion. There are few studies on iodine nutritional status for all age groups residing in the same area in Japan.

Gestational changes of thyroid function and urinary iodine in thyroid antibody-negative Japanese women.

Iodine is an essential nutrient for thyroid hormone synthesis, and iodine deficiency especially in pregnant and lactating women results in serious damage to their infants. To characterize iodine nutrition throughout gestation by using a food frequency questionnaire (FFQ) and urinary iodine concentration (UIC) measurement, and to establish appropriate gestational age-specific reference ranges for serum TSH and FT₄ in thyroid autoantibody (ThAb) negative euthyroid Japanese women, a total number of 563 pregnant women including 422 subjects with negative ThAbs, 105 postpartum women and their 297 newborn infants were included in the study. Dietary iodine intake (DII) was evaluated by FFQ.

Iodine status of pregnant and postpartum Japanese women: effect of iodine intake on maternal and neonatal thyroid function in an iodine-sufficient area.

Background: Iodine deficiency in pregnant and lactating women results in serious damage to their fetuses, newborns, and weaning infants. The effect of dietary iodine intake on maternal and infantile thyroid function has not been well studied in iodine-sufficient areas, and there are few data on appropriate gestational age-specific reference ranges for urinary iodine excretion during pregnancy and lactation.

Objectives: The aim of the study was to characterize the gestational change of urinary iodine excretion in Japanese women and to assess the effects of iodine status on thyroid function in mother and infant.

Smaller thyroid gland volume with high urinary iodine excretion in Japanese schoolchildren: normative reference values in an iodine-sufficient area and comparison with the WHO/ICCIDD reference.

Iodine deficiency disorders (IDDs) are serious global public health problems and approximately 2 billion people are at risk of IDD complications. Urine iodine and thyroid size by ultrasound in school-age children are important indicators for assessing IDD in a population. Interpretation of sonographically measured thyroid volume requires valid reference criteria from iodine-sufficient populations, and in 2003 WHO (World Health Organization)/ICCIDD (International Council for the Control of Iodine Deficiency Disorders) proposed new international reference values for thyroid volume in children aged 6-12 years.

Epidemiological survey of thyroid volume and iodine intake in schoolchildren, postpartum women and neonates living in Ulaan Baatar.

Objective: Although endemic goiter had been recognized in most parts of the country, there are few available data on iodine-deficiency disorders (IDDs) in Mongolia. This study aimed to characterize the current status of iodine deficiency in Ulaan Baatar, Mongolia's capital city.

Design: Cross-sectional, observational study designed and performed according to the surveillance methods for IDD prevalence recommended by WHO/UNICEF/ICCIDD.