Iodine Content Of Milk Research Articles

Iodine status in neonates in Denmark: regional variations and dependency on maternal iodine supplementation.

Iodine status of 147 neonates born in five different regions of Denmark was evaluated in relation to the iodine content of breast milk and iodine supplementation taken by the mother. Approximately two-thirds of the women had not received iodine supplementation. They had low iodine concentrations in breast milk and urinary iodine concentrations of the neonates at day 5 were low. The median values (milk/urine) were 33.6/31.7 micrograms/l (Randers 22/26, Ringkøbing 29/16, Aalborg 36/31. Arhus 54/41 and Copenhagen 55/59 micrograms/l). Higher values were found in the group where tablets containing iodine had been taken (milk/urine: 57.0/61.0 micrograms/l). In general, the values are low compared with internationally recommended levels. We suggest that mothers without autoimmune thyroid disease should receive iodine supplementation in the form of vitamin/mineral tablets containing iodine (150 micrograms per tablet).

Milk Iodine Content in Slovakia

The aim of this work was to map actual iodine status and its seasonal differences in raw milk of dairy cows, sheep, and goats in various regions of Slovakia. Iodine concentrations were determined in 457 samples of raw milk from dairy cows, 78 samples of sheep, and 16 samples of goat milk collected in various regions of Slovakia from 2002 to 2007. Among all the 457 samples of bovine milk, iodine content below 50 μg l-1 was recorded in 114 samples (24.94%); 294 samples (64.33%) ranged between 50 and 200 μg l-1; 19 samples (4.16%) from 200 to 500 μg l-1; 17 samples (3.72%) between 500 and 1 000 μg l-1, and 13 samples (2.85%) showed iodine concentrations over 1 000 μg l-1. regional concentrations showed the highest values in the Western, then Middle and Eastern Slovakia, and the lowest values in Northern Slovakia (p < 0.05, p < 0.01). In sheep and goat milk samples, we found iodine concentrations below 80 μg l-1 in 49 sheep (62.8%) and in 6 goats below 60 μg l-1 (37.5%), which are indicative of iodine deficiency. When comparing seasonal differences, sheep and goat milk had higher iodine content during the winter feeding period, however, in dairy cows we recorded the opposite ratio. Except for goat milk (p < 0.01) the seasonal differences were not significant.

Evaluation of urinary iodine excretion as a biomarker for intake of milk and dairy products in pregnant women in the Norwegian Mother and Child Cohort Study (MoBa)

Milk and dairy products are the main sources of iodine in the Norwegian diet. This is due to a high consumption of milk and dairy products combined with a relatively high concentration of iodine in milk because of mandatory iodine fortification of cow fodder. The aim of the present study was to investigate the relation between 24-h urinary iodine excretion and estimated dietary intake, and to explore the use of 24-h urinary iodine excretion as a possible biomarker for the intake of milk and dairy products when assessing the validity of a new food frequency questionnaire for pregnant women participating the Norwegian Mother and Child Cohort Study (MoBa). 119 women participated in a validation study. Iodine was analyzed in 24-h urine. Dietary intakes were estimated by a food frequency questionnaire (FFQ) and a 4-day weighed food diary (FD). Using linear regression, predictors of urinary iodine excretion were identified. The triangular method was applied to calculate validity coefficients. Significant predictors of 24-h urinary iodine excretion were: intake of dairy products, iodine-containing supplements and intake of fruit/vegetables. Fish/seafood intake and time of the year influenced 24-h urinary iodine excretion, although not significantly. The validity coefficients observed for total intake of dairy products were 0.65, 0.94 and 0.52 for the FFQ, the FD and the 24-h urinary iodine excretion, respectively. The present study showed that 24-h urinary iodine excretion may be a useful biomarker for validating the intake of milk and dairy products in pregnant Norwegian women.

Iodine nutrition of pregnant and lactating women in Hong Kong, where intake is of borderline sufficiency

To describe the iodine nutrition of pregnant and lactating women in Hong Kong, where intake is of borderline sufficiency. Review of cross-sectional and prospective studies. China, Hong Kong Special Administrative Region (SAR). Pregnant and lactating women. Studies of pregnant women in Hong Kong SAR have revealed an increase in the urinary iodine (UI) concentration as pregnancy advances. A significant percentage of women had a sub-normal serum thyroid hormone concentration at full term. Although iodine is concentrated by the mammary gland, 19% of all mothers had low iodine concentrations in their breast milk. The moderate correlation between the concentrations of iodine in breast milk and urine suggests that an adequate maternal urinary iodine concentration cannot reliably indicate that an infant is getting enough iodine in breast milk. Therefore, some breast-fed infants may still be at risk of low iodine intake, and additional iodine supplements, other than salt iodisation, would be warranted in this population. The currently recommended intake of iodine through universal salt iodisation may not be adequate for pregnant and lactating women, and supplementation during pregnancy and lactation should be further considered in light of the latest recommendations.

The impact of iodised salt or iodine supplements on iodine status during pregnancy, lactation and infancy

Monitoring of iodine status during pregnancy, lactation and infancy is difficult as there are no established reference criteria for urinary iodine concentration (UI) for these groups; so it is uncertain whether iodized salt programs meet the needs of these life stages. The method used in this paper was: 1) to estimate the median UI concentration that reflects adequate iodine intake during these life stages; and 2) to use these estimates in a review of the literature to assess whether salt iodisation can control iodine deficiency in pregnant and lactating women, and their infants. For pregnancy, recommended mean daily iodine intakes of 220-250 microg were estimated to correspond to a median UI concentration of about 150 microg l- 1, and larger surveys from the iodine sufficient countries have reported a median UI in pregnant women > or = 140 microg l- 1. Iodine supplementation in pregnant women who are mild-to-moderately iodine deficient is beneficial, but there is no clear affect on maternal or newborn thyroid hormone levels. In countries where the iodine intake is sufficient, most mothers have median breast milk iodine concentration (BMIC) greater than the concentration (100-120 microg l- 1) required to meet an infant's needs. The median UI concentration during infancy that indicates optimal iodine nutrition is estimated to be > or = 100 microg l- 1. In iodine-sufficient countries, the median UI concentration in infants ranges from 90-170 microg l- 1, suggesting adequate iodine intake in infancy. These findings suggest pregnant and lactating women and their infants in countries with successful sustained iodised salt programs have adequate iodine status.

Iodine nutrition in pregnancy and lactation in Iran

To describe studies evaluating urinary iodine excretion during pregnancy and lactation in women living in cities with adequate or more than adequate iodine intake. Cross-sectional study conducted between 1996 and 1998 in pregnant women and a study of lactating women conducted in 2003. Pregnant women attending prenatal clinics in four cities in the Islamic Republic of Iran. Urinary iodine excretion and thyroid volume was measured in 403 women. In a second study, 100 lactating women from Taleghani Hospital in Gorgan, Iran were evaluated for thyroid size, and both urinary and breast milk iodine concentrations were determined. In Rasht city, 84% of pregnant women had a urinary iodine concentration of > or = 200 microg l-1, while in the other cities this percentage ranged from 45 to 55%. When data were combined for the cities of Ilam, Isfahan and Tehran, where women have an adequate or more than adequate median urinary iodine concentration, 51% of pregnant women had a urinary iodine concentration less than that recommended during pregnancy. In Rasht, where the median urinary iodine concentration indicates an excessive iodine intake, 15.4% of pregnant women had a urinary iodine concentration < 200 microg l-1. The mean urinary iodine concentration in lactating women was 250 microg l-1, and 16% of women had a urinary iodine concentration < 100 microg l-1. Grade 1 goitre was present in 8% of lactating women, and another 8% had grade 2 goitre. Findings of this study call for further attention to iodine intake during pregnancy and lactation. The currently recommended intake of iodine through universal salt iodisation may not be adequate for pregnant and lactating women, and supplementation during pregnancy and lactation should be further considered in light of the latest recommendations.

Stable and radioiodine concentrations in cow milk: dependence on iodine intake

For testing the potential use of stable iodine as a countermeasure to reduce radioiodine transfer to milk, concentrations of stable iodine and radioiodine in the milk of dairy cows fed different amounts of stable iodine were measured. The results indicated that, compared to a normal average stable iodine intake of about 20 mg d −1 for cows, low iodine dietary intake (<1.5 mg d −1) resulted in a reduced transfer of radioiodine to milk by 25%, varying stable iodine intakes in the range of 10–500 mg d −1 did have no significant effect; at stable iodine intake rates above 1000 mg I d −1, a reduction by a factor of approximately two was achieved. The high dietary iodine intakes – being about 100 times the normal iodine supply – required to reduce the radioiodine transfer significantly, will result in stable iodine concentrations in milk in excess of advised or legal limits for human consumption. Nevertheless, the provision of stable iodine via the milk pathway might be considered for emergency situations when stable iodine is used as a preventative measure for dose reduction to humans.

Assessment of thyroid function and urinary and breast milk iodine concentrations in healthy newborns and their mothers in Tehran

To measure breast milk iodine (MI) and urinary iodine (UI) concentrations in healthy newborns and their nursing mothers from an iodine-sufficient region to determine adequacy and to relate these parameters to thyroid function tests in mothers and infants. Cross-sectional. Forty-eight healthy neonates of 37 to 42 weeks' gestation with normal cord blood TSH values and their mothers were recruited in Tehran, Iran. Serum thyroid function tests were performed, and maternal and infant urinary iodine excretion, and maternal MI concentration were measured. Neonatal age was 12.9 +/- 3.9 (mean +/- SD; range 7-30) days and maternal age was 25.8 +/- 5 years. Median (range) UI in neonates was 271 microg/l (57-800) and in mothers was 107 microg/l (20-710). Median (range) MI was 148 microg/l (45-750). Neonatal and maternal UI did not correlate with serum thyroid function tests. UI < 150, 150-230, and > 230 microg/l was found in 20, 12.5, and 67.5% of neonates and 79.1, 14, and 7% of mothers, respectively. MI was < 150, 150-180, and > 180 microg/l in 52.4, 11.9, and 35.7% of mothers, respectively. Among euthyroid neonates, UI was adequate despite low median maternal UI and MI concentrations. There were no significant correlations between UI or MI and thyroid function tests in the mothers and infants.

Enrichment of cow milk by feeding potassium iodide

Iodine is an essential dietary element for mammals, required for the synthesis of the thyroid hormones; thyroxin (T4, 3,5,3’,5’-tetraiodothyronine), and its active form T3 (3,5,3’-triiodothyronine) (SCF,2002). Thyroid hormones play a major role in the growth and development of brain and central nervous systems, control of several metabolic processes in body including carbohydrate, fat, protein, vitamin and mineral metabolism (EFSA, 2005). Milk and dairy products are an important source of iodine for human. Iodine concentration of cow milk can be influenced by its concentration in the diet or pasteurization process. A Linear correlation between iodine content of the diet and concentration in cow milk has been reported (Hemken; 1979, Fish &amp; Swenson; 1982, Lysbet et. al, 2003). This study was conducted in order to increase the iodine concentration of cow milk in accordance with human requirements by examining (i) inclusion rate of iodine in the animals diet and (ii) the effect of pasteurization process.

Breast Milk Iodine and Perchlorate Concentrations in Lactating Boston-Area Women

Breastfed infants rely on adequate maternal dietary iodine intake. Our objective was to measure breast milk iodine and perchlorate, an inhibitor of iodide transport into the thyroid and potentially into breast milk, in Boston-area women. The study included 57 lactating healthy volunteers in the Boston area. Breast milk iodine and perchlorate concentrations and urine iodine, perchlorate, and cotinine concentrations were measured. For comparison, iodine and perchlorate levels in infant formulae were also measured. Median breast milk iodine content in 57 samples was 155 microg/liter (range, 2.7-1968 microg/liter). Median urine iodine was 114 microg/liter (range, 25-920 microg/liter). Perchlorate was detectable in all 49 breast milk samples (range, 1.3-411 microg/liter), all 56 urine samples (range, 0.37-127 microg/liter), and all 17 infant formula samples (range, 0.22-4.1 microg/liter) measured. Breast milk iodine content was significantly correlated with urinary iodine per gram creatinine and urinary cotinine but was not significantly correlated with breast milk or urinary perchlorate. Perchlorate exposure was not significantly correlated with breast milk iodine concentrations. Perchlorate was detectable in infant formula but at lower levels than in breast milk. Forty-seven percent of women sampled may have been providing breast milk with insufficient iodine to meet infants' requirements.

Rapid acid digestion and simple microplate method for milk iodine determination

Iodine deficiency leads to deficiency of thyroid hormones, which causes mental retardation in infant. Laboratory confirmation is important in its diagnosis. The major problems associated with the existing methods for iodine determination in milk samples are: 1) nonsafe alkaline solution; 2) harsh thermal condition; and 3) extra time required to complete various steps. In this study, a simple and rapid colorimetric method was investigated, which used acid digestion in combination with a rapid microplate reading format method to determine the total iodine content in milk. Sample digestion was done on 50 microL milk in metavanadate/perchloric, at 230 degrees C for 10 min. After digestion, iodine determination was based on the Sandell-Kolthoff reaction. The reaction results were read in 96-well microplates by an enzyme-linked immunosorbent assay (ELISA) reader. The determination range of the assay was between 2 and 40 microg/dL. The within-run coefficient of variation percent in three levels (3, 12, and 36 microg/dL) ranged from 6.7 to 9.3 and between-run coefficients of variation ranged from 8.6 to 12.3%. The results obtained (n=70) by the optimized method have good correlation with the results of alkaline incineration as a reference method (n=70; r2=0.907; y=0.952x+1.77). Recovery tests for accuracy assessment in six levels from 6.2 to 34.2 microg/dL) were between 91.3 and 113%. This method has enabled us to achieve 0.12 microg/dL sensitivity. The results of this study show that a quick acid digestion combined with mild thermal and low sample volume with a quick reading of assay results were the main advantages of the acid digestion and microplate reading format.

Iodine content in raw milk

The paper presents the latest information on iodine content in raw milk, in the CzechRepublic. In 2005, iodine was determined using the Sandell-Kolthoff method in 169 milk samples, taken from transportation tanks (capacity 11 000&amp;ndash;13 000 litres) of collecting milk for dairy processing, from 14 areas of South-western Bohemia. The average iodine content in milk samples was 442.5 &amp;plusmn; 185.6 &amp;micro;g/l, minimum and maximum value were 68.6 and 1 000.6 &amp;micro;g/l respectively. 81.7% of the samples contained more than 250 &amp;micro;g/l. The average iodine content in milk from the collecting areas ranged from 230.2 &amp;plusmn; 133.0 &amp;micro;g/l to 702.7 &amp;plusmn; 166.2 &amp;micro;g/l (P &amp;lt; 0.001). In five collecting areas (i.e. 35.7%), means were higher than 500 &amp;micro;g/l. These values document the continuing trend of an increase in iodine content in raw cow&amp;rsquo;s milk, as well as permanent local and regional differences. Higher mean values were determined in the period of winter feed rations (April 495.9 &amp;plusmn; 50.8 and October 494.3 &amp;plusmn; 176.4 &amp;micro;g/l), while lower values were measured during the period of summer feed rations (September 350.9 &amp;plusmn; 178.4 &amp;micro;g I/l) (P &amp;lt; 0.01). If converted per dry matter, 1 kg of dry milk matter contained, on average, 3.428 &amp;plusmn; 1.497 mg iodine, maximum and minimum values were 0.543 and 7.995 mg respectively.

Hypothyroidism in a breast-fed preterm infant resulting from maternal topical iodine exposure

Hypothyroidism developed in a preterm infant, whose initial screening thyroid function test results were normal, at 2 weeks of life. The infant's mother was packing her Caesarian incision with iodine soaked gauze, resulting in a markedly increased breast milk iodine concentration. Treatment with oral L-thyroxine normalized thyroid function tests.

Selective preconcentration and determination of iodine species in milk samples using polymer inclusion sorbent

A method to determine low levels of iodine species namely I − and IO 3 − in aqueous samples was developed and applied to milk and milk powder samples. It is based on selective preconcentration of I − in polymer inclusion sorbent (PIS) and neutron activation analysis (NAA) of I − sorbed in PIS. The PIS was found to be highly selective for I − in presence of IO 3 − and other anions commonly present in the milk samples. In order to preconcentrate total I − + IO 3 − content in the PIS, IO 3 − was reduced to I − using a mixture of acetic acid and ascorbic acid. It was found that total iodine content in milk could be determined with epithermal neutron activation analysis (ENAA). A scheme was developed to determine I −, IO 3 − and total iodine. The developed method was applied to milk reference materials (NIST SRM-1549 and IAEA-RM-153 milk powder) and a commercially available milk powder. The scheme for estimation of iodine in different forms was validated by using reference material NIST SRM-1549.

Iodine concentrations in cow's milk in Central and Northern Bohemia

Iodine deficiency and related risks of medical and/or developmental disorders in humans are a worldwide problem. In the last years, Czech endocrinologists and paediatricians have observed a significant increase in the occurrence of goitre in children and adolescents caused by a low dietary intake of iodine. Given the low consumption of seafood, milk and dairy products are the main sources of iodine in theCzechRepublic. Iodine contents of milk of dairy cows of different breeds from seven farms located in Central andNorthern Bohemia were studied over a period of 17 months (April 2000 through August 2001). Iodine content was determined by high-performance liquid chromatography with electrochemical detection (HPLC-ECD) based on IDF Standard 167 (1994), following alkaline mineralization of the sample. An analysis of the certified reference material CRM&amp;nbsp;063 was used to examine the accuracy of determination. Two-way analysis of variance (ANOVA) with and without replications, including Scheffe&amp;rsquo;s comparison at a 5% level of significance, was used for statistical evaluation of experimental data. The iodine content of milk ranged from 147 to 605 &amp;micro;g/kg (mean 251  110 &amp;micro;g/kg) during the winter season, and from 35 to 484 &amp;micro;g/kg (mean 212  104 &amp;micro;g/kg) during the summer season. The mean iodine concentration in all samples of milk during the studied period was 225  109 &amp;mu;g/kg.The wide range of iodine concentrations is connected with differences in iodine saturation of dairy cows and it is a result of multiple factors. Iodine reserves in the soil play an important role and influence the content of iodine in feeds for dairy cows and thereby the iodine levels in milk. The presence of goitrogenic substances in feed for dairy cows is another important factor. The iodine content was found to be statistically significantly lower in the milk from dairy cows fed a diet enriched with rapeseed cakes compared to that of dairy cows on a diet without rapeseed cake. Dairy cows on farm F6, which were fed maize silage without added rapeseed cake during winter, had a statistically higher iodine content in milk during the winter season compared to summer, when they were fed fresh fodder. Fresh fodder is supposed to contain goitrogenic substances which significantly reduce iodine levels in milk. This opinion is supported by experimental findings that the date of milk sample collection has no statistically significant influence on milk iodine levels if the dairy cows are fed a diet containing added rapeseed cake (farms F1, F2, F3, and F4) throughout the year. Compared to the other farms, statistically significantly higher milk iodine content was found on farm F5. The mean iodine content in milk from farm F5 was 425  74 &amp;mu;g/kg during the studied period. The main cause is probably that the diet contained no rapeseed cake. &amp;nbsp;

TSH au cordon élevées au Maroc : hypothyroïdie iatrogène ?

A short prospective study was conducted to assess thyroid status in healthy full term newborns (n=90) of a large maternity of Marrakech (Morocco), as part of the validation of a national salt iodisation program. High TSH (>5mU/l) was detected in 89% of infants tested; urinary iodine excretion was measured in 35 of the mothers, and was found to be normal (100-200microg/l) or high (>200microg/l)(n=27) in all of them. Milk iodine concentration was measured in 315 lactating women from the same area. Low values (<41microg/l) were found in 60% of them. The common use of iodinated disinfectants during delivery could be responsible for the high urine iodine values of mothers; however iodine deficiency seems to remain a widespread problem in this population and justifies a large scale survey of iodine status.

Contribution of milk to daily intakes of iodine and bromine in northwestern Ukraine

The concentration of stable iodine and bromine in Ukrainian milk has been determined in relation to the effect of the Chernobyl nuclear power plant accident. The geometric mean of iodine and bromine concentration was 31.0mg/kg and 2.57 mg/kg, respectively. Compared with Japanese milk, it was statistically lower. Bromine concentrations in Ukrainian and Japanese milk were not significantly different. Contribution of milk to daily intake of iodine and bromine in Ukrainian adults has been estimated to 88% and 94%.

Declining iodine content of milk and re‐emergence of iodine deficiency in Australia

Declining iodine content of milk and re‐emergence of iodine deficiency in Australia

Dairy and acne—the iodine connection

To the Editor: I read with interest the study in the February 2005 issue of the Journal by Adebamowo et al1 regarding dietary dairy intake and an increased risk of developing teenaged acne. The authors hypothesize that this association may be caused by the presence of hormones and bioactive molecules in milk. Another hypothesis to help explain this association is that the iodine content of milk may also be playing a role in the development of the acne. It is well established that iodine intake can exacerbate acne.

An Assessment of Urinary and Breast Milk Iodine Concentrations in Lactating Mothers from Gorgan, Iran, 2003

Dietary iodine is essential for the production of thyroid hormones. Breast-fed infants are reliant on maternal iodine intake. The aim of this study was to evaluate iodine sufficiency in lactating women in Iran. The sample consisted of 100 lactating mothers referred to the Taleghani Hospital of Gorgan, Iran. Goiter was graded according to World Health Organization (WHO) classification. Spot urine and breast-milk samples were collected for the measurement of iodine concentrations. Urine iodine concentrations (UIC) less than 100 and breast-milk iodine concentrations (MIC) less than 50 microg/L were considered consistent with iodine deficiency. Forty-three percent of women had grade 1 and 2 goiters, respectively. The median UIC was 259 microg/L. UIC was less than 100 in 16%. Grade 1 and 2 goiters were each present in 8% of mothers with UIC less than 100 microg/L. The median MIC was 93.5 microg /L. MIC was less than 50 microg /L in 19%. Grade 1 and 2 goiters were present in 11% and 8%, respectively, of women with MIC <50 mg/L. MIC and UIC levels were significantly correlated (r = 0.44, p < 0.0001). Iodine deficiency and goiter were associated (p < 0.0001). UIC and MIC concentrations are sufficient in Gorgan, Iran. However, individual infants remain at risk for low iodine intake via breast milk.