Combined biofortification of carrot with iodine and selenium.

The aim of a three-year study was to assess the effect of combined biofortification with I and Se in carrot. Four cultivars ('Askona' F1, 'Samba' F1, 'Kazan' F1 and 'White Satin') were grown in soil fertilized with KI (4 kg I ha-1) and Na2SeO4 (0.25 kg Se ha-1). The I + Se fertilization did not affect yield but the plants of all cultivars accumulated both elements in leaves and roots. On average, the I and Se contents in roots increased 7.7-times for I and 4.9-times for Se as well as the average I:Se molar ratio was 0.28:1. The contents of both elements in roots remained well below the hazard threshold thus the intake of 100 g of biofortified carrot would substantially cover the RDA for I and Se. The changes in chemical composition of roots (nitrates, phenolic compounds, sugars, carotenoids, macro-, microelements and cadmium) were rather year-dependent than affected by the applied I + Se fertilization.

Effects of feed iodine concentrations and milk processing on iodine concentrations of cows' milk and dairy products, and potential impact on iodine intake in Swiss adults.

The contribution of milk and dairy products to daily iodine intake is high but variable in many industrialised countries. Factors that affect iodine concentrations in milk and dairy products are only poorly understood. Our aim was to: (1) assess the effect of feed iodine concentration on milk iodine by supplementing five groups of five cows each with one of five dosages from 0-2 mg iodine/kg DM; (2) quantify iodine losses during manufacturing of cheese and yogurt from milk with varying iodine concentrations and assess the effect of cellar-ripening; and (3) systematically measure iodine partitioning during heat treatment and skimming of milk. Milk iodine reached a near-steady state after 3 weeks of feeding. Median milk iodine (17-302 µg/l for 0-2 mg iodine/kg DM) increased linearly with feed iodine (R2 0·96; P < 0·001). At curd separation, 75-84 % of iodine was lost in whey. Dairy iodine increased linearly with milk iodine (semi-hard cheese: R2 0·95; P < 0·001; fresh cheese and yogurt: R2 1·00; P < 0·001), and cellar-ripening had no effect. Heat treatment had no significant effect, whereas skimming increased (P < 0·001) milk iodine concentration by only 1-2 µg/l. Mean daily intake of dairy products by Swiss adults is estimated at 213 g, which would contribute 13-52 % of the adults' RDA for iodine if cow feed is supplemented with 0·5-2 mg iodine/kg DM. Thus, modulation of feed iodine levels can help achieve desirable iodine concentrations in milk and dairy products, and thereby optimise their contribution to human iodine nutrition to avoid both deficiency and excess.

Assessing bioaccessibility of Se and I in dual biofortified radish seedlings using simulated in vitro digestion.

Selenium (Se) and iodine (I) are essential elements for humans, and biofortification of vegetables with these elements is an effective way to amend their deficiencies in the diet. In this study, the distribution and transformation of Se and I species were investigated in radish seedlings that were simultaneously supplemented with these two elements; the fate and the bioaccessibility of Se and I species were dynamically surveyed in the oral, gastric and intestinal phases using a simulated in vitro digestion method. The radish seedlings were cultivated in hydroponic conditions with Se (IV), Se (VI), I- and IO3- (each 1 mg L-1). The results revealed that Se-methylselenocysteine (MeSeCys), selenocystine (SeCys2), selenomethionine (SeMet) and Se (VI) were present in radish, and MeSeCys was the dominant species in both gastric and intestinal extracts, comprising 32.7 ±â€¯1.5% and 39.6 ±â€¯1.1% of the total content, respectively. I- was also the dominant species, which accounted for 57.1 ±â€¯2.1%, 46.6 ±â€¯1.5% and 68.8 ±â€¯1.8% of the total digested content respectively in the oral, gastric and intestinal extracts. Meanwhile, IO3- was absent and organic I accounted for approximately 20%. The bioaccessibility of Se and I in the intestinal phase reached 95.5 ±â€¯2.5% and 85.8 ±â€¯0.9%, respectively; although after dialysis through membranes, the data reduced to 60.1 ±â€¯2.8% and 39.6 ±â€¯0.8%, respectively. Contents of MeSeCys and I- increased from the oral to intestinal phase and the bioaccessibility of both Se and I in radish was above 85%. So radish is suitable as a potential dietary source of Se and I with biofortification.

Magnetite- and Iodine-Containing Nanoemulsion as a Dual Modal Contrast Agent for X-ray/Magnetic Resonance Imaging.

Noninvasive diagnostic by imaging combined with a contrast agent (CA) is by now the most used technique to get insight into human bodies. X-ray and magnetic resonance imaging (MRI) are widely used technologies providing complementary results. Nowadays, it seems clear that bimodal CAs could be an emerging approach to increase the patient compliance, accessing different imaging modalities with a single CA injection. Owing to versatile designs, targeting properties, and high payload capacity, nanocarriers are considered as a viable solution to reach this goal. In this study, we investigated efficient superparamagnetic iron oxide nanoparticle (SPION)-loaded iodinated nano-emulsions (NEs) as dual modal injectable CAs for X-ray imaging and MRI. The strength of this new CA lies not only in its dual modal contrasting properties and biocompatibility, but also in the simplicity of the nanoparticulate assembling: iodinated oily core was synthesized by the triiodo-benzene group grafting on vitamin E (41.7% of iodine) via esterification, and SPIONs were produced by thermal decomposition during 2, 4, and 6 h to generate SPIONs with different morphologies and magnetic properties. SPIONs with most anisotropic shape and characterized by the highest r2/ r1 ratio once encapsulated into iodinated NE were used for animal experimentation. The in vivo investigation showed an excellent contrast modification because of the presence of the selected NEs, for both imaging techniques explored, that is, MRI and X-ray imaging. This work provides the description and in vivo application of a simple and efficient nanoparticulate system capable of enhancing contrast for both preclinical imaging modalities, MRI, and computed tomography.

Is foliar enrichment of pea plants with iodine and selenium appropriate for production of functional food?

Pea (Pisum sativum L.) plants were sown in a field and foliar sprayed at blooming stage with solutions of different forms of iodine (I) - I- and IO3- and selenium (Se) - SeO32- and SeO42-. The possibility of enrichment of pea seeds to nutritionally important levels of both elements and their distribution through the plant parts were studied. To evaluate stress caused by application of I and Se, some morphological, physiological and biochemical characteristics were determined. The results showed elevated concentrations of both elements in all parts of pea plants. In seeds, I content was more than 6-fold higher, while Se content was up to 12-fold higher than in control plants. Although the plants were in good condition, some differences in pod characteristics and electron transport system activity were observed. Glutathione content was not affected by any treatment and only the I- + SeO42- combination decreased the amount of anthocyanins in plants.

Hybrid spectral CT reconstruction.

Current photon counting x-ray detector (PCD) technology faces limitations associated with spectral fidelity and photon starvation. One strategy for addressing these limitations is to supplement PCD data with high-resolution, low-noise data acquired with an energy-integrating detector (EID). In this work, we propose an iterative, hybrid reconstruction technique which combines the spectral properties of PCD data with the resolution and signal-to-noise characteristics of EID data. Our hybrid reconstruction technique is based on an algebraic model of data fidelity which substitutes the EID data into the data fidelity term associated with the PCD reconstruction, resulting in a joint reconstruction problem. Within the split Bregman framework, these data fidelity constraints are minimized subject to additional constraints on spectral rank and on joint intensity-gradient sparsity measured between the reconstructions of the EID and PCD data. Following a derivation of the proposed technique, we apply it to the reconstruction of a digital phantom which contains realistic concentrations of iodine, barium, and calcium encountered in small-animal micro-CT. The results of this experiment suggest reliable separation and detection of iodine at concentrations ≥ 5 mg/ml and barium at concentrations ≥ 10 mg/ml in 2-mm features for EID and PCD data reconstructed with inherent spatial resolutions of 176 µm and 254 µm, respectively (point spread function, FWHM). Furthermore, hybrid reconstruction is demonstrated to enhance spatial resolution within material decomposition results and to improve low-contrast detectability by as much as 2.6 times relative to reconstruction with PCD data only. The parameters of the simulation experiment are based on an in vivo micro-CT experiment conducted in a mouse model of soft-tissue sarcoma. Material decomposition results produced from this in vivo data demonstrate the feasibility of distinguishing two K-edge contrast agents with a spectral separation on the order of the energy resolution of the PCD hardware.

Daily Consumption of Lipid-Based Nutrient Supplements Containing 250 µg Iodine Does Not Increase Urinary Iodine Concentrations in Pregnant and Postpartum Women in Bangladesh.

Background: Maternal iodine deficiency during pregnancy and lactation is common in Bangladesh.Objective: We evaluated the effect of lipid-based nutrient supplements for pregnant and lactating women (LNS-PL) on urinary iodine concentration (UIC).Methods: We conducted a cluster-randomized controlled effectiveness trial in which we enrolled 4011 pregnant women at ≤20 gestational weeks. Women in 48 clusters received iron and folic acid (IFA; 60 mg Fe/d + 400 µg folic acid/d) and women in 16 clusters received LNS-PL (20 g/d, 118 kcal) containing 22 vitamins and minerals (including 250 µg I). We randomly selected a subsample of 1159 women for repeated urine sample collection, i.e., at enrollment, at 36 wk of gestation, and at 6 mo postpartum, for UIC analysis, a secondary outcome of the trial.Results: The geometric mean UIC at 36 wk of gestation and at 6 mo postpartum did not differ significantly between the IFA and LNS-PL groups. The median (quartile 1, quartile 3) UIC at 36 wk was 27.4 µg/L (16.9, 52.7 µg/L) in the IFA group and 30.2 µg/L (17.7, 56.6 µg/L) in the LNS-PL group; at 6 mo, these were 23.0 µg/L (10.0, 45.9 µg/L) in the IFA group and 22.2 µg/L (9.1, 50.4 µg/L) in the LNS-PL group.Conclusion: Daily consumption of LNS-PL containing 250 µg I did not increase the UICs of pregnant and lactating women in Bangladesh. Iodine from lipid-based nutrient supplements may have been stored in the thyroid gland or secreted in breast milk instead of being excreted in urine. Additional research that uses other biomarkers of iodine status is needed to determine how to meet the iodine requirements of pregnant and lactating women in Bangladesh and similar settings. This trial was registered at clinicaltrials.gov as NCT01715038.

The Impact of Carrot Enriched in Iodine through Soil Fertilization on Iodine Concentration and Selected Biochemical Parameters in Wistar Rats.

Iodine is one of the trace elements which are essential for mammalian life. The major objective of iodine biofortification of plants is to obtain food rich in this trace element, which may increase its consumption by various populations. Additionally, it may reduce the risk of iodine deficiency diseases. In this research for the first time we have assessed the bioavailability of iodine from raw or cooked carrot biofortified with this trace element on iodine concentration in selected tissues and various biochemical parameters as well as mRNA expression of some genes involved in iodine metabolism in Wistar rats. Statistically, a significantly higher iodine level was determined in urine, faeces and selected tissues of rats fed a diet containing biofortified raw carrot as compared to a diet without iodine and a diet containing control cooked carrot. Biofortified raw carrot significantly increased triiodothyronine concentration as compared to animals from other experimental groups. The highest thyroid stimulating hormone level was determined in rats fed control cooked carrots. mRNA expression of selected genes was affected by different dietary treatment in rats' hearts. Biofortified raw and cooked carrot could be taken into account as a potential source of iodine in daily diets to prevent iodine deficiency in various populations.

Evaluating the response of gastric carcinomas to neoadjuvant chemotherapy using iodine concentration on spectral CT: a comparison with pathological regression.

AIM: To investigate the potential of iodine concentration (IC) determined using virtual monochromatic spectral computed tomography (CT) to predict the response of gastric carcinomas to preoperative neoadjuvant chemotherapy (NC). MATERIALS AND METHODS: A total of 20 patients were enrolled who underwent two spectral CT examinations (1 week before and two cycles after NC). The percentage change in tumour thickness (%ΔCWT) and in IC on the arterial phase (%ΔIC-a) and venous phase (%ΔIC-v) after NC were calculated and compared for different histopathological regression grades and response groups. The diagnostic efficacies to discriminate good response (GR) and poor response (PR) of the above three parameters were evaluated using receiver operating characteristic (ROC) curves. RESULTS: The decrease rate of %ΔIC-a for the GR group was higher than that for the PR group (-0.59 [-0.76, -0.20] versus -0.11 [-0.75, 0.92], p=0.012). There was no significant difference in the %ΔIC-v and %ΔCWT values between the GR and PR groups (p=0.076 and p=0.779, respectively). The areas under the ROC curve (AUC) values were 0.857, 0.762, and 0.542 for %ΔIC-a, %ΔIC-v, and %ΔCWT, respectively, in the response prediction. The cut-off value for identifying PR was a decrease rate of <52.9% for %ΔIC-a, and the sensitivity and specificity values were 0.857 and 0.833. CONCLUSION: Changes in the IC for gastric carcinomas following NC were detected using spectral CT and correlated with histopathological regression. The prediction efficacy for IC was better than that for tumour thickness, with IC on the arterial phase being a better predictor than IC on the venous phase.

Low-level seaweed supplementation improves iodine status in iodine-insufficient women.

Iodine insufficiency is now a prominent issue in the UK and other European countries due to low intakes of dairy products and seafood (especially where iodine fortification is not in place). In the present study, we tested a commercially available encapsulated edible seaweed (Napiers Hebridean Seagreens® Ascophyllum nodosum species) for its acceptability to consumers and iodine bioavailability and investigated the impact of a 2-week daily seaweed supplementation on iodine concentrations and thyroid function. Healthy non-pregnant women of childbearing age, self-reporting low dairy product and seafood consumption, with no history of thyroid or gastrointestinal disease were recruited. Seaweed iodine (712 µg, in 1 g seaweed) was modestly bioavailable at 33 (interquartile range (IQR) 28-46) % of the ingested iodine dose compared with 59 (IQR 46-74) % of iodine from the KI supplement (n 22). After supplement ingestion (2 weeks, 0·5 g seaweed daily, n 42), urinary iodine excretion increased from 78 (IQR 39-114) to 140 (IQR 103-195) µg/l (P< 0·001). The concentrations of thyroid-stimulating hormone increased from 1·5 (IQR 1·2-2·2) to 2·1 (IQR 1·3-2·9) mIU/l (P< 0·001), with two participants having concentrations exceeding the normal range after supplement ingestion (but normal free thyroxine concentrations). There was no change in the concentrations of other thyroid hormones after supplement ingestion. The seaweed was palatable and acceptable to consumers as a whole food or as a food ingredient and effective as a source of iodine in an iodine-insufficient population. In conclusion, seaweed inclusion in staple foods would serve as an alternative to fortification of salt or other foods with KI.

Dietary iodine absorption is not influenced by malabsorptive bariatric surgery.

BACKGROUND: Bariatric surgery is accompanied by malabsorption of protein, carbohydrates, fats, vitamins, and trace elements. Iodine is essential to the synthesis of thyroid hormones. The aim of this study was to estimate the daily iodine intake in severely obese patients before and after bariatric surgery. METHODS: Thirty-five severely obese patients (obese group) with a BMI of 51.3 ± 8.3 kg/m(2) were studied before, 3 months, and 6 months after bariatric surgery. Eleven out of 35 patients were subjected to gastric bypass operation Roux-en-Y and 24 were subjected to a variant of biliopancreatic diversion with long limb procedure. The patients did not use any iodine supplements and no iodine antiseptics were administered during the operation. The messmates of the patients, following a similar diet (control group) with a BMI of 31.2 ± 10.7 kg/m(2), were also studied. Serum T3, T4, TSH, thyroid peroxidase antibodies, urinary iodine excretion (UIE) in a spot urine, and thyroid volume were measured in all subjects, at baseline and at 3- and 6-month follow-up in the obese group. RESULTS: UIE at baseline was similar in obese and control group (median (min-max), 129.5 (24.9-462) vs. 138.9 (30.8-381) µg/L, ns). In the obese group, a transient increase of UIE was observed 3 months after the operation and returned to baseline levels 6-months postsurgery. CONCLUSIONS: The UIE is not reduced after malabsorptive bariatric surgery, although all stomach, duodenum, and a substantial part of jejunum were bypassed. It appears that iodine is absorbed sufficiently along the remaining gastrointestinal tract.

An innovative approach for iodine supplementation using iodine-rich phytogenic food.

Iodine, as one of the essential trace elements for human body, is very important for the proper function of thyroid gland. In some regions, people are still suffering from iodine deficiency disorder (IDD). How to provide an effective and cost-efficient iodine supplementation has been a public health issue for many countries. In this review, a novel iodine supplementation approach is introduced. Different from traditional iodine salt supplement, this approach innovatively uses cultivated iodine-rich phytogenic food as the supplement. These foods are cultivated using alga-based organic iodine fertilizer. The feasibility, mechanics of iodine absorption of plants from soil and the bioavailability of iodine-rich phytogenic food are further discussed.

The impact of iodinated contrast agent administered during preoperative computed tomography scan on body iodine pool in patients with differentiated thyroid cancer preparing for radioactive iodine treatment.

BACKGROUND: Iodine in iodinated contrast agents (ICAs) interferes with radioactive iodine treatment (RAIT) and diagnostic scans in patients with differentiated thyroid carcinoma (DTC) because it can compete with ¹³¹I. Published guidelines recommend delaying RAIT for three to four months in patients who have been exposed to ICA. Spot urinary iodine concentration is a useful marker to reflect the body iodine pool. We investigated the impact of ICAs administered at preoperative computed tomography (CT) scan on the body iodine pool to determine the proper time interval between preoperative CT and RAIT in DTC patients. METHODS: We performed a retrospective review of 1023 patients with DTC who underwent a preoperative CT scan with ICA, total thyroidectomy, and one week of low-iodine diet in preparation for RAIT. Urine iodine excretion (UIE) was measured in spot urine by inductively coupled plasma mass spectrometry and reported both in simple concentration (µg/L) and divided by gram creatinine (µg/gCr). Patients were divided into five groups by time interval in days between preoperative CT scan and spot urine iodine measurement (A, 31-60 [n=29]; B, 61-90 [n=155]; C, 91-120 [n=546]; D, 121-150 [n=226]; E, 151-180 [n=67]). RESULTS: The median (interquartile range) of UIE (µg/gCr) in each group was 44.4 (27.7-73.2) in group A, 33.3 (22.8-64.7) in group B, 32.7 (20.8-63.0) in group C, 32.0 (20.6-67.0) in group D, and 30.4 (19.6-70.8) in group E. There was no significant difference between group A and the remaining groups (p>0.05) Also, the proportion of patients who achieved the appropriate UIE for RAIT according to our hospital's cutoff (≤66.2 µg/gCr) was not different between groups (A, 72.4%; B, 76.1%; C, 77.5%; D, 74.8%; E, 74.6%) (p=0.78). CONCLUSION: This study shows that a UIE of one month after preoperative CT scan with ICA was not higher than that of six months after CT scan in patients who underwent total thyroidectomy for DTC. Thus, current guidelines that recommend delay of RAIT for three to four months after CT scan with ICA should be revisited and future studies to clarify the appropriate time interval between CT scan with ICA and RAIT are warranted.

Iodine uptake and prostate cancer in the TRAMP mouse model.

Iodine supplementation exerts antitumor effects in several types of cancer. Iodide (I⁻) and iodine (I2) reduce cell proliferation and induce apoptosis in human prostate cancer cells (LNCaP and DU-145). Both chemical species decrease tumor growth in athymic mice xenografted with DU-145 cells. The aim of this study was to analyze the uptake and effects of iodine in a preclinical model of prostate cancer (transgenic adenocarcinoma of the mouse prostate [TRAMP] mice/SV40-TAG antigens), which develops cancer by 12 wks of age. ¹²5I⁻ and ¹²5I2 uptake was analyzed in prostates from wild-type and TRAMP mice of 12 and 24 wks in the presence of perchlorate (inhibitor of the Na⁺/I⁻ symporter [NIS]). NIS expression was quantified by quantitative polymerase chain reaction (qPCR). Mice (6 wks old) were supplemented with 0.125 mg I⁻ plus 0.062 mg I2/mouse/day for 12 or 24 wks. The weight of the genitourinary tract (GUT), the number of acini with lesions, cell proliferation (levels of proliferating cell nuclear antigen [PCNA] by immunohistochemistry), p53 and p21 expression (by qPCR) and apoptosis (relative amount of nucleosomes by enzyme-linked immunosorbent assay) were evaluated. In both age-groups, normal and tumoral prostates take up both forms of iodine, but only I⁻ uptake was blocked by perchlorate. Iodine supplementation prevented the overexpression of NIS in the TRAMP mice, but had no effect on the GUT weight, cell phenotype, proliferation or apoptosis. In TRAMP mice, iodine increased p53 expression but had no effect on p21 (a p53-dependent gene). Our data corroborate NIS involvement in I⁻ uptake and support the notion that another transporter mediates I2 uptake. Iodine did not prevent cancer progression. This result could be explained by a strong inactivation of the p53 pathway by TAG antigens.

EURRECA-Estimating iodine requirements for deriving dietary reference values.

Iodine is an essential component of thyroid hormones, and current recommendations for intake are based on urinary iodine excretion, assessment of thyroid size, thyroidal iodine accumulation and turnover, radioactive iodine uptake, balance studies, and epidemiological studies. Dietary iodine is rapidly and almost completely absorbed. The prevalence of inadequate iodine intake is high: 29% of the world's population lives in iodine-deficient areas and 44% of Europe remains mildly iodine deficient. To assess current data and update evidence for setting dietary recommendations for iodine, the EURRECA Network of Excellence has undertaken systematic review and evaluation of (i) the usefulness of iodine status biomarkers (ii) the relationship between iodine status biomarkers and dietary iodine intake, and (iii) the relationship between iodine intake and health outcomes (endemic goiter, hypothyroidism, and cognitive function). This review summarizes the main research outputs: the key findings of the literature review, results of the meta-analyses, and discussion of the main conclusions. Currently, data for relevant intake-status-health relationships for iodine are limited, particularly for population groups such as children under two years, pregnant women, and the elderly. The EURRECA Network developed best practice guidelines for the identification of pertinent iodine studies based on a systematic review approach. This approach aimed to identify comparable data, suitable for meta-analysis, for different countries and across all age ranges. When new data are available, the EURRECA Network best practice guidelines will provide a better understanding of iodine requirements for different health outcomes which could be used to set evidence-based dietary iodine recommendations for optimal health.

One month is sufficient for urinary iodine to return to its baseline value after the use of water-soluble iodinated contrast agents in post-thyroidectomy patients requiring radioiodine therapy.

BACKGROUND: There is a concern regarding the use of iodinated contrast agents (ICA) for chest and neck computed tomography (CT) to localize metastatases in patients with differentiated thyroid cancer (DTC). This is because the iodine in ICA can compete with (131)I and interfere with subsequent whole scans or radioactive iodine treatment. The required period for patients to eliminate the excess iodine is not clear. Therefore, knowing the period for iodine levels to return to baseline after the injection of ICA would permit a more reliable indication of CT for DTC patients. The most widely used marker to assess the plasmatic iodine pool is the urinary iodine (UI) concentration, which can be collected over a period of 24 hours (24U) or as a single-spot urinary sample (sU). As 24U collections are more difficult to perform, sU samples are preferable. It has not been established, however, if the measurement of iodine in sU is accurate for situations of excess iodine. METHODS: We evaluated 25 patients with DTC who received ICA to perform chest or neck CT. They collected 24U and sU urinary samples before the CT scan and 1 week and 1, 2, and 3 months after the test. UI was quantified by a semiautomated colorimetric method. RESULTS: Baseline median UI levels were 21.8 µg/dL for 24U and 26 µg/dL for sU. One week after ICA, UI median levels were very high for all patients, 800 µg/dL. One month after ICA, however, UI median levels returned to baseline in all patients, 19.0 µg/dL for 24U and 20 µg/dL for sU. Although the values of median UI obtained from sU and 24U samples were signicantly different, we observed a significant correlation between samples collected in 24U and sU in all evaluated periods. CONCLUSION: One month is required for UI to return to its baseline value after the use of ICA and for patients (after total thyroidectomy and radioiodine therapy) to eliminate the excess of iodine. In addition, sU samples, although not statistically similar to 24U values, can be used as a good marker to evaluate patients suspected of contamination with iodine.

Iodine nutrition in pregnancy and lactation.

Adequate iodine intake is required for the synthesis of thyroid hormones that are important for normal fetal and infant neurodevelopment. In this review, we discuss iodine physiology during pregnancy and lactation, methods to assess iodine sufficiency, the importance of adequate iodine nutrition, studies of iodine supplementation during pregnancy and lactation, the consequences of hypothyroidism during pregnancy, the current status of iodine nutrition in the United States, the global efforts toward achieving universal iodine sufficiency, and substances that may interfere with iodine use.

Utilisation of iodine from different sources by sows and their progeny.

OBJECTIVES: The aim of the study was to compare iodine utilization from different sources by sows and their progeny and the levels of T3 and T4 in their serum. DESIGN: Pregnant Czech Large White × Landrace sows were fed with an experimental KPK diet (a diet for lactating sows) 14 days before parturition until weaning (at a piglet age of 28 days). In group A (n=50, 10 sows, 40 piglets) the feed was supplemented with KI (0.6 mg of iodine per kg of feed). Iodine enriched alga Chlorella spp. (0.6 mg of iodine per kg of feed) was used as a supplement in group B (n=50, 10 sows, 40 piglets). In group C (n=50, 10 sows, 40 piglets) the sows were injected i.m. with IFAE at a dose of 100 mg of iodine per sow. Iodine, T3 and T4 were measured in each group for comparison of iodine utilization. RESULTS: The use of IFAE resulted in higher serum concentrations in sows compared to KI and alga. In contrast, iodine concentrations in milk and piglets were lower when IFAE were used. We found a wide variation in the concentrations of T3 and T4 in the serum of piglets in all groups. CONCLUSION: Our results indicate a good utilization of iodized oil by sows. However, its transfer into milk is lower compared to the other iodine sources.

Biofortification of lettuce (Lactuca sativa L.) with iodine: the effect of iodine form and concentration in the nutrient solution on growth, development and iodine uptake of lettuce grown in water culture.

BACKGROUND: Iodine is an essential trace element for humans. Two billion individuals have insufficient iodine intake. Biofortification of vegetables with iodine offers an excellent opportunity to increase iodine intake by humans. The main aim was to study the effect of iodine form and concentration in the nutrient solution on growth, development and iodine uptake of lettuce, grown in water culture. RESULTS: In both a winter and summer trial, dose rates of 0, 13, 39, 65, and 90 or 129 microg iodine L(-1), applied as iodate (IO(3)(-)) or iodide (I(-)), did not affect plant biomass, produce quality or water uptake. Increases in iodine concentration significantly enhanced iodine content in the plant. Iodine contents in plant tissue were up to five times higher with I(-) than with IO(3)(-). Iodine was mainly distributed to the outer leaves. The highest iodide dose rates in both trials resulted in 653 and 764 microg iodine kg(-1) total leaf fresh weight. CONCLUSION: Biofortification of lettuce with iodine is easily applicable in a hydroponic growing system, both with I(-) and IO(3)(-). I(-) was more effective than IO(3)(-). Fifty grams of iodine-biofortified lettuce would provide, respectively, 22% and 25% of the recommended daily allowance of iodine for adolescents and adults.

Iodine excess.

Several mechanisms are involved in the maintenance of normal thyroid hormone secretion, even when iodine intake exceeds physiologic needs by a factor of 100. The sodium-iodide symporter system contributes most to this stability. Faced with an iodine excess, it throttles the transport of iodide into the thyroid cells, the rate-limiting step of hormone synthesis. Even before the iodine symporter reacts, a sudden iodine overload paradoxically blocks the second step of hormone synthesis, the organification of iodide. This so-called Wolff-Chaikoff effect requires a high (>or=10(-3) molar) intracellular concentration of iodide. The block does not last long, because after a while the sodium-iodide symporter shuts down; this allows intracellular iodide to drop below 10(-3) molar and the near-normal secretion to resume. In some susceptible individuals (e.g., after radio-iodine treatment of Graves' disease or in autoimmune thyroiditis), the sodium-iodide symporter fails to shut down, the intracellular concentration of iodide remains high and chronic hypothyroidism ensues. To complicate matters, iodine excess may also cause hyperthyroidism. The current explanation is that this happens in persons with goitres, for example, after long-standing iodine deficiency. These goitres may contain nodules carrying a somatic mutation that confers a 'constitutive' activation of the TSH receptor. Being no more under pituitary control, these nodules overproduce thyroid hormone and cause iodine-induced hyperthyroidism, when they are presented with sufficient iodine. These autonomous nodules gradually disappear from the population after iodine deficiency has been properly corrected. More recent studies suggest that chronic high iodine intake furthers classical thyroid autoimmunity (hypothyroidism and thyroiditis) and that iodine-induced hyperthyroidism may also have an autoimmune pathogenesis.