Arsenic Cerium Catalytic Spectrophotometry Research Articles

Analysis of iodine nutritional status of children aged 8-10 years in Zhejiang Province from 2016 to 2021

Objective: To analyze the iodine nutrition status of children aged 8 to 10 years in Zhejiang Province from 2016 to 2021. Methods: A multi-stage stratified sampling method was used to select non-residential children aged 8 to 10 years from 90 counties in Zhejiang Province. A total of 114 103 children were included in the study from 2016 to 2021. Direct titration method and arsenic-cerium catalytic spectrophotometry were used to detect salt iodine content and urinary iodine level, respectively, to evaluate the iodine nutritional status of children. Ultrasound was used to detect thyroid volume and analyze the current prevalence of goiter in school-age children. Results: The age of 114 103 children was (9.04 ± 0.81) years old, with 50.0% of (57 083) boys. The median of iodine content M (Q1, Q3) in children's household salt was 23.00 (19.80, 25.20) mg/kg, including 17 242 non-iodized salt, 6 173 unqualified iodized salt, and 90 688 qualified iodized salt. The coverage rate of iodized salt was 84.89%, and the coverage rate of qualified iodized salt was 79.48%. The proportion of non-iodized salt increased from 11.85% in 2016 to 16.04% in 2021 (χ2trend=111.427, P<0.001). The median of urinary iodine concentration M (Q1, Q3) in children was 182.50 (121.00, 261.00) μg/L, among which the proportions of iodine deficiency, iodine suitability, iodine over suitability, and iodine excess were 17.25% (19 686 cases), 39.21% (44 745 cases), 26.85% (30 638 cases), and 16.68% (19 034 cases), respectively. The median of urinary iodine concentration in children in inland areas [M (Q1, Q3): 190.90 (128.80, 269.00) μg/L] was significantly higher than that in children in coastal areas [M (Q1, Q3): 173.00 (113.00, 250.30) μg/L] (P<0.001). From 2016 to 2021, a total of 39 134 ultrasound examinations were conducted, and 1 229 cases of thyroid enlargement were detected. The goiter rate was 3.14% (95%CI: 2.97%-3.32%). The incidence of goiter in children in coastal areas [3.45% (95%CI: 3.19%-3.72%), 641/18 604] was higher than that in children in inland areas [2.86% (95%CI: 2.64%-3.10%), 588/20 530] (P=0.001). Conclusion: From 2016 to 2021, the iodine nutrition level of children aged 8-10 years in Zhejiang Province is generally suitable, and the rate of goiter in children meets the limit of iodine deficiency disease elimination standards.

Dietary Iodine Intake and Pattern of Thyroid Disorders among the Ethnic Population of Eastern Himalayan Ranges of India

Background and Aim: In the present study, dietary iodine intake and thyroid functioning were assessed among the ethnic adolescent group of Eastern Himalayan range with the hypothesis that insufficient iodine intake negatively affects normal thyroid functions. The aim of the study was to see the prevalence and relation between iodine deficiency and thyroid functioning. Materials and Methods: It is a hospital-based study conducted in the health care facilities of Dima Hasao district, Assam, from April 2021 to March 2022. The study included 821 subjects including both male and female of adolescent age group (10–19 years). The thyroid profiling, anti-Thyroid peroxidase antibody (anti-TPO Ab), and urinary iodine content (UIC) were carried out. Thyroid hormone analysis was carried out by chemiluminescence assay. The anti-TPO Ab was determined using the electrochemiluminescence immunoassay analyzer. The dietary iodine intake was measured on the basis of UIC and was determined by arsenic cerium catalytic spectrophotometry method by the Sandell-Kolthoff reaction. Results: The prevalence of thyroid disorder among the studied population was found to be 13.8%. Among different conditions of thyroid disorders, hypothyroidism was present in 10.6% and hyperthyroidism in 3.13%. 4.18% had elevated anti-TPO Ab. Among the euthyroid subjects with different thyroid disorders, 1.48% and 21% had anti-TPO Ab positivity, respectively. The median UIC was 99.97 µg/l. 25.78% of the population had iodine deficiency. Thyroid disorders were common in subjects with iodine deficiency (61.34%) than iodine sufficient subjects (20%). Conclusion: The work was an attempt to demonstrate how the dietary iodine intake influences thyroid functioning among the adolescent ethnic population of Eastern Himalayas which is manifested as high prevalence of subclinical hypothyroidism with iodine deficiency. The work underscores region specific recommendation on iodine supplementation for populations living in geographically remote locations.

Chronic Iodine Intake Excess Damages the Structure of Articular Cartilage and Epiphyseal Growth Plate.

This study aimed to explore the influence of excess iodine on the articular cartilage and epiphyseal growth plate in rats. Wistar rats (n = 200) were randomly divided into five groups with 40 rats in each: normal iodine (NI), 5-fold high iodine group (5HI), 10-fold high iodine group (10HI), 50-fold high iodine group (50HI), and 100-fold high iodine group (100HI). The rats were executed in 6 and 12months. 24-h urinary iodine concentration (UIC) was monitored by arsenic-cerium catalytic spectrophotometry. The chemiluminescence method was used to determine the thyroid function. The pathological changes in the epiphyseal plate, articular cartilage, and thickness of the epiphyseal plate were observed. The mRNA expression of collagen II (ColII), collagen X, matrix metalloproteinase-13 (MMP-13), and fibroblast growth factor receptor 1 in articular chondrocytes was detected by RT-PCR. 24-h UIC increased as iodine intake increased. In the 12th month, there was a significant increase in serum sTSH and a decrease in serum FT4 in HI groups, compared to the NI group. There was a decrease in the number of proliferating cells in the epiphyseal plate and an increase in the number of mast cell layers. The chondrocytes appeared disorganized, and the tidal lines were disturbed or even broken. Growth plate thickness decreased with increasing iodine intake. Compared with the NI group, ColII and MMP-13 mRNA expression in chondrocytes in all HI groups significantly increased. Chronic iodine overdose increases the risk of hypothyroidism. Chronic iodine overdose leads to abnormal morphology of epiphyseal growth plates and articular cartilage, increasing the risk of osteoarthritis.

Serum iodine concentration and its associations with thyroid function and dietary iodine in pregnant women in the southeast coast of China: a cross-sectional study.

Iodine deficiency is a major public health problem in pregnant women. Serum iodine (SI) may represent a useful biomarker for iodine nutrition evaluation. We aimed to assess the relationship between serum iodine concentration (SIC) and urinary iodine concentration (UIC), dietary iodine, thyroid function, and thyroid diseases in pregnant women in the southeast coast of China, and to provide a normal reference range of SIC for pregnant women. A multistage random sampling method was used to select the study population. We collected urine and blood samples from pregnant women and determined UIC and SIC as well as thyroid function using Arsenic-Cerium Catalytic Spectrophotometry, inductively coupled plasma mass spectrometry, and Beckman Coulter Access2 chemiluminescent immunoanalyzer and kit, respectively, and administered a questionnaire on dietary iodine intake in pregnant women. There was a significant negative correlation between SI and thyroid-stimulating hormone (TSH) (r = -0.141) and a significant positive correlation between SI and free triiodothyronine (FT3) (r = 0.106), free thyroxine (FT4) (r = 0.236), triiodothyronine (TT3) (r = 0.229), total thyroxine (TT4) (r = 0.433), and dietary iodine intake (r = 0.068). There was a significant difference in SI levels of pregnancy between the second (78.13 μg/L) and third trimester (75.37 μg/L) (p = 0.018). SI levels between inadequate intake (74.58 μg/L) and appropriate intake (77.92 μg/L) groups were statistically different (p = 0.036). Low SIC was a risk factor for the development of hypothyroxinemia (adjusted OR = 3.14, 95% confidence interval: 1.75-5.66). The reference range for SIC in normal pregnant women is 45.03-112.44 μg/L. SI may be a composite indicator of iodine nutritional status and thyroid function.

A study of programmed death-1/programmed death ligand and iodine-induced autoimmune thyroiditis in NOD.H-2h4 mice.

Excess iodine will trigger the occurrence of autoimmune thyroiditis (AIT), and programmed death-1 (PD-1)/programmed death ligand (PD-L) will also contribute to the development of AIT. The purpose of this study was to explore the role that negative regulatory signals mediated by PD-1/PD-L play in the development of spontaneous autoimmune thyroiditis (SAT) in NOD.H-2h4 mice when they are exposed to iodine. Programmed death ligand 1 (PD-L1) antibody was administered intraperitoneally to NOD.H-2h4 mice. The relevant indicators were determined by flow cytometry, real-time quantitative polymerase chain reaction, enzyme-linked immunosorbent assay, immunohistochemistry, pathological hematoxylin and eosin staining, and arsenic-cerium catalytic spectrophotometry. Results showed that the level of urinary iodine, the level of thyroid lymphocyte infiltration, the level of thyroglobulin antibodies (TgAb) and interferon (IFN-γ)/tumor necrosis factor (TNF-α)/interleukin (IL-2)/IL-17, and the relative expression of PD-1/PD-L1/programmed death-2 (PD-L2) increased with the intervention of excess iodine. After the intervention of the PD-L1 antibody, the expression of PD-1/PD-L1/PD-L2 in different degrees was inhibited, but the level of thyroid lymphocyte infiltration and serum TgAb/IFN-γ/TNF-α/ IL-2/IL-17 did not decrease. Collectively, although PD-1/PD-L participates in the occurrence of SAT and induces inflammation, administration of the PD-L1 antibody does not effectively improve the pathological process of SAT. More research is needed to determine whether PD-1/PD-L intervention can treat autoimmune thyroid disease.

Effects of Excessive Iodine on the BDNF-TrkB Signaling Pathway and Related Genes in Offspring of EAT Rats.

Excess iodine can cause autoimmune thyroiditis (AIT) in women, but it is unclear whether this has any implications for neurodevelopmental mechanisms in offspring. We studied the effects of experimental autoimmune thyroiditis (EAT) rats with different amounts of iodine intake on offspring brain development via the brain-derived neurotrophic factor (BDNF)-tropomycin receptor kinase B (TrkB) signaling pathway, because BDNF plays an important role in neurodevelopment. Rats in three thyroglobulin (Tg) immunized groups with varying iodine intakes (Tg (100µg/L iodine), Tg + High-iodine I group (Tg + HI, 20mg/L iodine), and Tg + High-iodine II group (Tg + HII, 200mg/L iodine)) were injected with 800µg Tg once every 2weeks for 3 times. Rats in the control group (NI, 100µg/L iodine) were immunized with saline. Arsenic-cerium catalytic spectrophotometry was used to measure urine iodine levels. The lymphocytic infiltration in the thyroids was observed by histopathological studies. Thyroid autoantibodies levels were measured using radioimmunoassay. The norepinephrine (NE) contents were measured by an enzyme-linked immunosorbent assay. The levels of the BDNF-TrkB signaling pathway and related genes were measured by quantitative real-time PCR and Western blot. Urinary iodine levels increased as iodine intake increased. Lymphocytes were significantly aggravated in Tg-immunized rats. Serum thyroglobulin antibody (TgAb) and thyroid peroxidase antibody (TPOAb) levels were clearly elevated in Tg-immunized rats. Tg-immune groups had significantly lower NE levels. The BDNF-TrkB signaling pathway and related gene mRNA and protein levels were found to be significantly lower in Tg-immune groups with higher iodine levels. Maternal AIT may reduce the levels of certain neurodevelopmental mechanisms in the offspring, such as the BDNF-TrkB signaling pathway and related factors, while excessive iodine consumption by the mother may exacerbate this effect.

Iodine nutrition level and thyroid function in pregnant women in the Yongchuan district of Chongqing

This study aims to investigate thyroid function-associated parameters and the incidence of thyroid disorders in pregnant women, with the overarching aim to ensure that pregnant women do not develop said disorders due to aberrant iodine levels during the course of pregnancy. A total of 300 pregnant women who underwent routine check-ups at the Yongchuan Hospital Affiliated to Chongqing Medical University from January to December 2021 were enrolled. Venous blood and morning urine were collected. Serum thyroid-stimulating hormone (TSH), free thyroxine (FT4), and free triiodothyronine (FT3) were determined by chemiluminescence immunoassay. Urinary iodine concentration (UIC) was detected by arsenic cerium catalytic spectrophotometry. Thyroid disorders were extrapolated from the measured parameters. The overall median UIC was 203 μg/L, which was within normal range. Subgroup analysis revealed that the median UIC in the first trimester was 187.5 μg/L, 211.8 μg/L in the second trimester, and 239.9 μg/L in the third trimester. However, based on the WHO criteria, 32%, 30%, and 18% of pregnant women were iodine deficient during their first, second, and third trimester, respectively. The proportion of women with iodine deficiency in the first and second trimesters was higher compared to the third trimester (P < 0.05). Serum FT3 and FT4 concentrations were higher in subjects in their first and second trimester versus the third trimester, while serum TSH levels were lower in subjects in their first and second trimester versus the third trimester (P < 0.05). The TSH concentration in subjects with inadequate iodine intake (UIC < 150 μg/L) was lower compared to subjects with adequate iodine intake (UIC 150 - 249 μg/L), but higher than in subjects with more than adequate intake (UIC 250 - 499 μg/L) and excess iodine intake (UIC ≥ 500 μg/L) (P < 0.05). TSH concentration and UIC were positively correlated (r = 0.1945, P = 0.0007), while no relationship was observed between UIC and FT3 and FT4 serum levels (r1 = -0.0593, P1 = 0.3053; r2 = -0.0149, P2 = 0.7968). There was no significant difference in FT3 and FT4 concentration between different UIC strata (P > 0.05). The incidence of thyroid disease during pregnancy in iodine-deficient women was greater compared to pregnant women with adequate iodine intake (P < 0.05) and higher in subjects in the more than adequate as well as excessive iodine intake cohorts (P < 0.05). The iodine nutritional intake by pregnant women in Yongchuan District, Chongqing, was generally sufficient to meet developmental and metabolic needs. However, about a third of women in their first and second trimester exhibited iodine deficiency. Iodine deficiency was associated with an increased incidence of thyroid diseases. In clinical practice, the UIC of pregnant women should be measured during key stages in the pregnancy to prevent the manifestation of thyroid diseases.

Effects of high potassium iodate intake on iodine metabolism and antioxidant capacity in rats

BackgroundKIO3 and KI are the most common salt iodization agents. Coincidentally, iodine exists naturally in high-iodine drinking water in the form of iodide (I−) or iodate (IO3−). As an oxidizing substance, IO3− should be reduced to I− before it can be effectively used by the thyroid. However, there is a lack of systematic studies on the metabolic process of high dose KIO3in vivo. MethodsThe iodine metabolism processes in the thyroid and serum of rats after high KIO3 intake were determined using high-performance liquid chromatography-inductively coupled plasma-mass spectrometry (HPLC/ICP–MS) and arsenic cerium catalytic spectrophotometry. The changes of redox activity in the serum, thyroid, liver, and kidneys were observed by detecting total antioxidative activity (TAA). ResultsHigh doses of IO3− were completely reduced to I−in vivo within 0.5 h. The level of organic bound iodine in the serum was stable, while the organic bound iodine in the thyroid increased to a plateau after intake of high-dose KIO3. The levels of total iodine and I− in serum and thyroid increased quickly, then all decreased after reaching the maximum absorption peak, and I− had two absorption peaks in serum. The thyroid blocking dose of I− was 0.5 mg/kg in rat. Additionally, high KIO3 intake did not influence the TAA in serum and other tissues. ConclusionThe body is able to reduce and utilize high doses of KIO3 ingested through the digestive tract. The metabolism of high KIO3in vivo is characterized by two absorption process of I− in serum and the thyroid blocking effect. Moreover, a single intake of high-dose KIO3 does not affect TAA in vivo. The results suggest that such excess IO3− may have be reduced in the digestive tract before I− enters the blood.

Iodine deficiency in pregnant women after the adoption of the new provincial standard for salt iodization in Zhejiang Province, China

BackgroundZhejiang has achieved the goal of elimination of iodine deficiency disorders (IDD) via the implementation of universal salt iodization (USI) since 2011. Iodine content in household table salt decreased from the national standard (35 ppm) to the Zhejiang provincial standard (25 ppm) in 2012. It is crucial to periodically monitor iodine status in pregnant women because IDD in pregnancy have adverse effects on fetal neurodevelopment.MethodsWe carried out a cross-sectional study between April 2014 and September 2015 in the eight sentinel surveillance counties across Zhejiang Province, where IDD was previously known to be endemic. A total of 1304 pregnant women participated and provided a random spot urine sample and a household table salt sample. Urinary iodine concentration (UIC) was determined using arsenic-cerium catalytic spectrophotometry. Iodine content in salt was measured using a titration method with sodium thiosulphate.ResultsOverall, the median UIC of the total study population of pregnant women was 129.3 μg/L, with a higher UIC in inland (152.54 μg/L) and a lower UIC in coastal counties (107.54 μg/L). Household coverage of iodized salt was 94.6% and the rate of adequately iodized salt was 89.9%.ConclusionsOur results indicate deficient iodine status in the pregnant population of Zhejiang, according to the lower cut-off value of optimal iodine nutrition (150 μg/L) recommended by the World Health Organization. In addition to sustaining USI, more efforts are urgently needed to improve iodine intake in women during pregnancy, especially those residing in the coastal counties.

Sample preparation for iodine measurement by arsenic cerium catalytic spectrophotometry

Objective To screen the suitable sample digestion method for measuring iodine in serum by arsenic cerium catalytic spectrophotometric method, and to carry out the methodology test for the newly developed arsenic cerium catalytic spectrophotometry for determination of iodine in serum. Methods Methodology evaluation. Experimentswere on the sample on the sample digestion method of serum iodine with several common digestive agents. After digestion treatment, the concentration of iodine in serum was determined by arsenic cerium catalytic spectrophotometry. The linearity and linear range of the standard curve, detection limit, precision, recovery rate and anti-interference ability of the newlydeveloped arsenic cerium catalytic spectrophotometry were tested. Results Sample pretreatment method included in the newly developed arsenic cerium catalytic spectrophotometry was selected as follows: perchloric acid-sodium chlorate solution was used as the digestive agent to digest 120 min at 130℃. The calibration relation of C=a+ blgA(C: iodine concentration, A: measuring absorbance) of the newly developed method existed when arsenic ceriumcatalytic reaction was kept at a certain stable temperature range from 13℃ to 30℃ and in certain stable reacting time. The linear range of the calibration curvewas 0 -300 μg/Land the linear correlative coefficient was -0.9996--0.9999. The intra assay coefficients of variation(CVs ) were 0.70%, 0.70% and 0.74% (n=6), and the inter assay CVs were 0.57%, 0.51% and 0.57% (n=6) for 3 serum samples. The average recovery was 97.9% with a range from 92.3% to 105.8% for 3 serum samples. Conclusions The newly developed arsenic cerium catalytic spectrophotometry has good precision and accuracy. The sample digestion agent is easy to be prepared and reserved, and the instrument is simple and easy to be operated. The method can be widely used as a reliable technique for measuring iodine in serum.(Chin J Lab Med, 2017, 40: 119-125) Key words: Iodine; Serum; Reference standards; Spectrophotometry; Arsenicals; Cerium

Survey of iodine nutritional status in 2011, Zhejiang, China.

Universal salt iodization (USI) was introduced in China in 1995, but whether the iodine status is optimal is questionable. This study was conducted to assess the iodine nutrition among Zhejiang population in coastal regions in China. A cross-sectional survey for iodine nutritional status was conducted with general population (n=10,350), including pregnant and lactating women (n=450 each) selected by stratified multistage sampling. Iodine content in drinking water, table salt and urine, were determined using arsenic-cerium catalytic spectrophotometry, the direct titration and the arsenic-cerium catalytic spectrophotometry, respectively, and daily iodine intake was estimated by 3 days of 24-hour recall method. The median iodine content in drinking water was 2.46 μg/L, Zhejiang belonged to the region of iodine deficiency in outer environment according to China standard. The median iodine content in table salt was 27.9 mg/kg, conforming to the standard requirements; the household coverage rate of qualified iodized salt reached 76.8%, which does not reach the standard requirement of WHO >90%. The dietary iodine intake of a reference individual averaged 379 μg/d, which indicated that the current iodine intake in diet was appropriate. In addition, the median urinary iodine concentration (UIC) was 162 μg/L in general population, and 130 μg/L in pregnant women, which didn't reach the standard requirements. The current dietary iodine intake in Zhejiang was generally sufficient and safe, but there is a risk of iodine deficiency among pregnant women and the population who do not consume iodized salt.

The prospective study on thyroid carcinoma correlated with urine iodine level in Urmuqi region

Objective To investigate the association of thyroid carcinoma and urine iodine level in Urumqi region, intent to provide the evidence of individual iodine supplement of this region. Methods In this case-control study, there were 100 patients with thyroid carcinoma and 300 patients with normal thyroid function as the control group in Xinjiang Tumor Hospital between February 2012 and December 2012 as the case group. All the cases were detected for urine iodine concentration by arsenic-cerium catalytic spectrophotometry. Results The mean level of urinary iodine in the case group (272.69 μg/L) was higher than that in the control group (161.40 μg/L) (P 300 μg/L) in 34 % (34/100) patients in the case group and 10 % (30/300) patients in control group (P<0.05). Conclusion The average urinary iodine content of the thyroid carcinoma in Urmuqi region are generally higher than that of the healthy control group, which indicates that the iodine nutritional status in patients with thyroid carcinoma are better than that in the general population. The relationship between thyroid carcinoma and excessive iodine intake should be necessary for further study. Key words: Thyroid neoplasms; Urine iodine; Urmuqi

The nutritional status of iodine in children and its correlation with thyroid size in Kashi, Xinjiang

Objective To investigate the nutritional status of iodine in children in Kashi and to evaluate the relationship between urinary iodine and thyroid size.Methods Twelve counties in Kashi were investigated.Urinary iodine was determined by arsenic-cerium catalytic spectrophotometry,and iodine in water by arsenic-cerium oxidationreduction method,and iodized salt was tested by direct titration.Type B ultrasonography to determine length and thickness of thyroid gland was performed in selective counties.Result The median water iodine was ＜ 10 μg/L,but with the rise of coverage rate and qualified rate of iodized salt,the median urinary iodine became 177.05 μg/L.The frequency distribution was different among different counties,there were 6 counties (＞20％) being iodine deficient,and 5 counties (＞20％) with iodine excess.Moreover,urinau iodine showed no difference between Uygur and Han,upland and plain,city and countryside.Furthermore,urinary iodine was correlated with right lobe width and thickness (r=0.113,P=0.012; r=0.092,P=0.04).Conclusion The iodine deficient situation is basically corrected in Kashi,however a more refined iodine supplement project is needed to prevent thyroid diseases. Key words: Nutritional status of iodine ; Urinary iodine ; Thyroid size

Application of iodine metabolism analysis methods in thyroid diseases

The main physiological role of iodine in the body is to synthesize thyroid hormone. Both iodine deficiency and iodine excess can lead to severe thyroid diseases. While its role in thyroid diseases has increasingly been recognized, few relevant platforms and techniques for iodine detection have been available in China. This paper summarizes the advantages and disadvantages of currently iodine detection methods including direct titration, arsenic cerium catalytic spectrophotometry, chromatography with pulsed amperometry, colorimetry based on automatic biochemistry, inductively coupled plasma mass spectrometry, so as to optimize the iodine nutrition for patients with thyroid diseases.

Study on the iodine status of pregnant women and thyroid function of neonate in high iodine area

To reveal the iodine status of pregnant women and its impact on thyroid function of neonates in high iodine area. A total of 210 pregnant women were chosen from a hospital in Haixing county, Hebei province. Pregnant women's random urinary and neonates' cord blood were collected. The urinary iodine concentration (UIC) was examined by arsenic-cerium catalytic spectrophotometry. The levels of free triiodothyronine (FT3), free thyroxine (FT4) and sensitive thyroid-stimulating hormone (sTSH) in serum were measured by chemiluminescence. The age of 210 pregnant women was (27.69 +/- 4.73) years old, whose urinary iodine median (inter-quartile range ) was 1240.70 (1292.68) microg/L. 84.3% (177/210) of the pregnant women had excessive iodine intake (UIC > or = 500 microg/L), 13.8% (29/210) had more than adequate iodine intake( UIC within 250 - 499 microg/L), 0.5% (1/210) had adequate iodine intake (UIC within 150 - 249 microg/L) and 1.4% (3/210) had insufficient iodine intake (UIC < 150 microg/L). The average serum level of FT3, FT4 in neonates were (2.93 +/- 0.59), (15.03 +/- 1.92) pmol/L, respectively. The median (inter-quartile range) of serum sTSH in neonates were 7.33 (5.59) mU/L 78.1% (164/210) of the neonates' serum TSH were beyond 5 mU/L. There were no correlation between pregnant women's urinary iodine level and neonates' serum FT3 and sTSH level (P > 0.05), but there was a positive correlation between pregnant women's urinary iodine level and neonates' serum FT4 level (P < 0.01). Serum FT4 level of the neonates with whose mothers had insufficient iodine intake ((12.99 +/- 1.10) pmol/L) were statistically lower than those with their mothers had excessive iodine intake (15.16 +/- 1.83) pmol/L) (P < 0.05). Most of the pregnant women in high iodine area were excessive for iodine nutrition, but still a few pregnant women had insufficient iodine nutrition. The level of neonates' serum sTSH were relatively high and monitoring of risk of hypothyroidism and subclinical hypothyroidism should be strengthened.

Study on content of iodine in food in Tianjin market and iodine nutrition conditions among college students

To know about content of iodine in foods sold in Tianjing markets presently, and the iodine nutrition conditions in college students. It was also aimed to probe the functions of the iodized salt complement with the dietary iodine intake, and whether the urine iodine could reflect dietary iodine intake. 278 food samples in markets were collected by a randomly stratified sampling method, while the arsenic-cerium catalytic contact method was used to determine the content in food. The dietary information of students for seven days was recorded, and the urine iodine was determined through the arsenic-cerium catalytic spectrophotometry. The determination of 47 kinds and 278 food samples indicated that the content of iodine within animal foods (7.8 microg/100 g - 30.8 microg/100 g) was higher than that within plant foods (1.8 microg/100 g - 16.1 microg/100 g). The investigation also showed that students who regarded vegetarian food as principle accounted for 70. 19%. The amount of dietary iodine intake among those students, based on the dietary survey, was (111.67 +/- 53.18) microg/d, while supplementary iodine from iodized salt was about (230.27 +/- 45.55) microg/d. Therefore, the total iodine provided from diet would be (341.95 +/- 89.58) microg/d. Modified by urine creatinine, the median of urine iodine was 271.28 microg/gCr, and the urine iodine and dietary iodine intake was found positively related (r(s) = 0.463, P < 0.01). Regarding the vegetarian food as the principle, most of students investigated are not rich. The dietary iodine intake is lower than RDA (150 microg), but it can be obtained the iodized salt by 230. 27 microg, which is the possible supplement to the shortage from foods.