Iodine Content Of Milk Research Articles

The Assessment of Iodine Concentrations in Colostrum and Breast Milk Using ICP-MS: The Impact of Delivery Type, Thyroid Function and Gestational Diabetes-A Pilot Study.

Considering the spectrum of benefits of breast milk feeding, determining the essential components of an infant's only food-mother's milk-seems justified, especially in the case of those whose deficiency (e.g., iodine) may result in developmental disorders. The main aim of this study was the determination of the total iodine content of breast milk (including colostrum and mature milk). A secondary objective was to assess the influence of factors such as the type of delivery, hypothyroidism, gestational diabetes or the stage of lactation on this parameter. The study materials were colostrum and milk after 1 (n = 14), 2 and 3 months (n = 8) of lactation with a range of iodine concentrations (µg/L): 195-1648 and 170-842, 174-650 and 273-751, respectively. Iodine was determined using the inductively coupled plasma mass spectrometry (ICP-MS). Multivariate statistical analysis revealed, e.g., that delivery by caesarean section or dose of L-thyroxine taken by women to normalise thyroid hormones, had a significant effect on iodine concentrations in breast milk. Further research aimed at assessing the quality of breast milk should also include determining the factors influencing it.

Ecological monitoring of iodine in pastoral ecosystems

The problem of iodine deficiency is relevant in many countries, including Ukraine, and has serious health consequences due to the insufficient iodine content in food. In order to overcome iodine deficiency, it is important to be based on monitoring the iodine content in food and water in the relevant area. An excessive increase in iodine in salt can cause hyperthyroidism. Monitoring iodine-deficient areas in rural areas becomes especially important, as plants grown on soils with low iodine content may contain insufficient amounts of this element, which can lead to severe iodine deficiency among the population. Iodine is also important for animal health and can improve animal performance. Some plants accumulate iodine from the soil, which can improve their resistance to diseases and negative factors, and the interaction of iodine with other chemical elements is also important. The article summarizes scientific data on the peculiarities of the iodine cycle in the soil-plant-animal chain in pastoral ecosystems, develops recommendations for assessing and overcoming iodine deficiency in ecosystems of this type. The iodine content was determined by a method based on the oxidation of iodide to iodine with the subsequent addition of NH2CONH2 to destroy excess nitrite. The subject of the study were soils., plants of pastoral ecosystems and milk. In the mountainous zone of pastoral ecosystems, a significant iodine deficiency in soils was detected, due to the iodine-deficient nature of the territory. A similar, but less pronounced deficit is observed in the foothills and plains of Northern Bukovina. The iodine content in the green mass of plants does not have general patterns and is not confined to natural zones. The lowest iodine content was found in Plantago major L. Iodine deficiency in milk is more pronounced and decreases from the plain to the mountainous zone. A close correlation was established between the iodine content in the soil and the density of livestock, as well as the indicators of pasture digression. A high correlation between the iodine content in milk and its content in plants was found. Crops adapted to iodine deficiency conditions cannot withstand the effects of recommended iodine concentrations, which can adversely affect yields. However, lower iodine concentrations can stimulate seed germination.

Asparagopsis taxiformis inclusion in grass silage-based diets fed to Norwegian red dairy cows: Effects on ruminal fermentation, milk yield, and enteric methane emission

Efforts to mitigate enteric methane (CH4) emission from ruminants by using the red macroalgae Asparagopsis taxiformis (AT) have demonstrated promising results both in vitro and in vivo. We assessed the effects of wild harvested and freeze-dried AT inclusion in the grass silage-based diets of Norwegian Red dairy cows on feed intake, milk yield and composition, rumen fermentation and CH4 emission. Fifteen (9 rumen cannulated and 6 intact) multiparous cows with an average (±SD) covariate period milk yield (MY) of 33.0 (3.8) kg/day were used in the experiment. The cows were divided into three groups (n = 5) after blocking for cannulation, and initial MY. After feeding on a common diet for 21 days (i.e., Covariate period), the groups were randomly allocated to three treatments: Control (no seaweed), 0.125%AT (Control + 0.125%AT, on organic matter (OM) basis) and 0.25%AT (Control + 0.25%AT, on OM basis). The cows were adapted to their diets for 13 days, followed by 39 experimental days for data collection. Inclusion of AT at 0.125% level did not affect dry matter intake (DMI, kg/d) but signicantly reduced both MY and energy corrected milk yield (ECM, kg/d) (P < 0.05) with a tendency for lower CH4 production (g/d) relative to the control group. Dry matter intake, ECM and CH4 production were reduced (P < 0.05) by 0.25%AT inclusion relative to the Control group. Apparent total tract nutrient digestibility (%), ECM per kg DMI, CH4 yield (g CH4/kg DMI) and CH4 intensity (g CH4/kg ECM) were not affected by AT inclusion. Inclusion of AT, at both levels, significantly reduced (P < 0.05) ruminal fluid total short chain fatty acids and molar proportions of actate, while increasing (P < 0.05) the molar proportion of propionate and isovalerate. Inclusion of AT decreased contents (%) of milk fat (P = 0.018) and protein (P = 0.010) resulting in significanly lower fat and protein yields. Lactose content (%) was higher for the AT groups (P = 0.021) but this did not compensate for lower MY resulting in lower milk lactose yield. Milk iodine content increased in a dose dependent manner with AT inclusion. In conclusion, AT inclusion at 0.25% level reduced CH4 emission from dairy cows with a grass silage-based diets. However, the reduced DMI for the 0.25%AT group along with reduced MY and elevated milk iodine content for both AT groups, for this particular harvest of AT, would suggest possible constraints for large scale inclusion of AT in dairy cow production.

Iodine Metabolism in Urine and Breast Milk among Lactating Women with Adequate Iodine

BackgroundIn lactating women, iodine metabolism is regulated and maintained by the kidneys and mammary glands. Limited research exists on how iodine absorbed by lactating women is distributed between the kidneys and breasts. ObjectivesThis study aimed to accurately evaluate the total iodine intake (TII), urinary iodine excretion (UIE), and breast milk iodine excretion (BMIE) in lactating women and explore the relationship between TII and total iodine excretion (TIE). MethodsA 7-d iodine metabolism study was conducted on 41 lactating women with a mean age of 30 y in Yuncheng and Gaoqing, China, from December 2021 to August 2023. TII and TIE were calculated by measuring the iodine content in food, water, 24-h urine, feces, and breast milk. The urinary iodine excretion rate (UIER), breast milk iodine excretion rate (BMIER), and partitioning of iodine excretion between urine and breast milk were determined. ResultsIodine metabolism studies were performed for 285 d. The median TII and TIE values were 255 and 263 μg/d, respectively. With an increase in TII, UIER, and BMIER, the UIE and BMIE to TII ratio exhibited a downward trend. The median UIER, BMIER, and proportion of iodine excreted in urine and breast milk were 51.5%, 38.5%, 52%, and 37%, respectively. When the TII was <120 μg/d, the BMIER decreased with the increase of the TII (β: −0.90; 95% confidence interval: −1.08, −0.72). ConclusionsWhen maternal iodine intake is low, the proportion in breast milk increases, ensuring sufficient iodine nutrition for infants. In addition, the UIE of lactating women with adequate iodine concentrations is higher than their BMIE.This study was registered at clinicaltrials.gov as NCT04492657.

Factors affecting iodine content of cow milk-A review

This review discusses the importance of iodine as an essential nutrient for human health and the factors that can influence the concentration of iodine in cow milk. For an adult, the daily recommended requirement of iodine is 150 µg/day and the maximum tolerable limit ranges from 600 to 1100 µg/day. Cow milk is a significant source of iodine in many countries, particularly in areas where iodine-rich foods are not readily available. Therefore, evaluating the variables that affect the iodine content of cow milk is important. The iodine concentration of cow milk can vary depending on several factors such as genetics, diet, environment, management practices, season, and processing. Particularly, dietary supplementation and feed composition have been identified as the most impactful on milk's iodine levels, offering a practical approach to mitigating iodine deficiency. Furthermore, environmental factors like soil and water iodine content and management practices, including the type of farming, play substantial roles. Seasonal changes also significantly affect iodine levels, with higher concentrations typically observed in winter due to different feeding practices. The iodine content of cow milk falls between 147 to 605 µg/kg and the highest value of 11100 µg/L was recorded in camel milk. Milk could supply up to 60% of the daily dietary requirement of iodine for an adult person. To fight iodine deficiency through the appropriate approach to such concerns, one must have an in-depth understanding of these issues. This review paper aims to provide a comprehensive analysis of these factors and their implications for human and public health strategies. Bangladesh Journal of Animal Science 53 (1): 1-12, 2024

The Potential Significance of Algae in Agriculture Field By IJISRT

As a vast and varied collection of microbes, algae are capable of photosynthesis, which allows them to convert energy from sunlight into chemical compounds. The agricultural sector relies heavily on algae due to their usefulness as biofertilizers and soil stabilizers. The use of algae, especially seaweeds, as fertilizers leads to a decrease in nitrogen and phosphorus discharge compared to that produced by animal dung. The water that eventually makes its way into rivers and seas is therefore of higher quality. As dietary supplements for humans, these creatures are farmed all over the globe. They need very little water to grow, and they may be cultivated on desert and abandoned land, producing food that is both clean and carbon neutral. Iodine is abundant in seaweeds. The dietary intake of the milking cow determines the milk's iodine content. If you want more iodine in your milk, feed your cows seaweed. Incorporating algae into chicken feed speeds up the egg- laying process. This article provided a concise overview of algae and its agricultural applications, covering the essentials for anyone involved in this field.

Assessment of energy dispersive X-ray fluorescence (ED-XRF) for quantification of iodine in non-lyophilized milk.

Iodine represents a fundamental element for human health, with particular regard to thyroid function. Dietary intake of milk naturally rich in iodine becomes of primary importance in the prevention of syndromes related to iodine deficiency. The concentration of iodine in milk is characterized by wide variability, mainly related to animal feed and level of mineral supplementation. Therefore, there is interest in the development of fast analytical techniques which are able to predict milk iodine concentration. The aim of the present study was to investigate the effectiveness of energy-dispersive X-ray fluorescence (ED-XRF) for the prediction of iodine in cow milk. Results showed moderate accuracy of the ED-XRF technique, with a coefficient of determination in cross validation of 0.60. This study represents a first contribution towards the possibility to discriminate milk with high or low iodine concentration, as an essential preliminary step for the introduction into the market of naturally fortified milk.

The effects of dietary iodine content, milking system, and farming practices on milk iodine concentration and quality traits

Various management practices can influence milk quality traits in dairy cattle. As an example, an increasing investment in automatic milking system to substitute milking parlors has been observed in the last 2 decades in dairy farms which could have affected certain bulk milk quality traits. What is more, milking practices can also affect certain milk parameters; as an example, teat disinfectants containing I are used in commercial farms where pre- or postdipping is performed, leading to presence of some I in the bulk milk. However, this trace mineral is also supplied in cows' diet to fulfill their nutritional requirements, partly contributing to the milk I final concentration. Therefore, the aim of this study was to evaluate the sources of variation of milk I along with other traditional milk quality traits. A total of 91 dairy farms in northeastern Italy were enrolled in the study. In each farm, diet and bulk milk samples were collected on the same day for chemical analysis. Concentration of I, in particular, was determined in both milk and feed with gold standard. Pearson correlations were calculated among the traits available for milk and diet, and a general linear model was used to test significance of fixed effects (feeding system, milking system, farming system, herd size, herd stage of lactation, and sampling month) on milk quality traits including the I concentration. In the case of milk I, diet I and presence of I-based predipping and postdipping teat disinfect application were also tested as fixed effects. Results showed a positive linear correlation between milk and diet I content (correlation coefficient [r] = 0.78). Although milk I was also positively correlated with lactose content (r = 0.25), dietary I was not correlated with other milk traits. Milk I content was significantly affected by dietary I, I-based predipping teat disinfectant application, and herd composition. Compared with conventional farms, organic farms showed lower protein content and greater somatic cell score (SCS) but similar milk I. Milking system significantly affected only lactose content and SCS of milk. Sampling month was only significant for milk urea nitrogen and herd composition, feeding system, herd size, and herd average days in milk did not modify milk gross composition and SCS. In conclusion, dietary supply of I is the main factor affecting milk I concentration and findings suggest that I level in milk can be naturally improved in dairy cows by modulating the I content in the diet administered. However, further research is needed to evaluate the effect of I-based sanitizers on milk I.

Iodine concentration and palatability of milk from cows fed the common red seaweed species Himanthalia elongata

Iodine concentration and palatability of milk from cows fed the common red seaweed species Himanthalia elongata

Iodine Concentration in the Breast Milk and Urine as Biomarkers of Iodine Nutritional Status of Lactating Women and Breastfed Infants in Taiwan.

Breast milk iodine concentration (BMIC) can be different when median urinary iodine concentration (UIC) is similar. The BMIC, UIC/creatinine (Cr), estimated 24-h urinary iodine excretion (24-h UIE) of lactating women in Taiwan is unknown. This study enrolled lactating women from Taipei Veterans General Hospital (August 2021-February 2023). Each participant provided a random spot urine sample, two breast milk samples, a blood sample, and completed a food frequency questionnaire on the same day. Iodine measurement was performed by inductively coupled plasma mass spectrometry. The median UIC of the enrolled 71 women was 91.1 μg/L, indicating insufficient iodine status; however, the median BMIC was 166.6 μg/L and this suggested that the amount of iodine delivered through breast milk was adequate for the breastfed infants. BMIC was correlated with UIC/Cr and 24-h UIE (both rs = 0.49) but not with UIC (rs = 0.18) or thyroid stimulating hormone (rs = 0.07). Women who did not consume dairy products (adjusted odds ratio: 24.41, 95% confidence interval: 1.26-471.2) and multivitamins (adjusted odds ratio: 8.26, 95% confidence interval: 1.76-38.79) were at increased odds for having lower BMIC. The results suggest that measuring maternal UIC alone may not be sufficient, as BMIC, UIC/Cr, and 24-h UIE are all important biomarkers. Ingestion of dairy products and multivitamins were independently associated with BMIC.

Iodine Nutrition in Children ≤2 years of Age in Norway

BackgroundAs a component of the thyroid hormones (THs), iodine is vital for normal neurodevelopment during early life. However, both deficient and excess iodine may affect TH production, and data on iodine status in young children are scarce. ObjectivesTo describe iodine nutrition (iodine status and intake) in children ≤2 y of age in Innlandet County (Norway) and to describe the associations with maternal iodine nutrition. MethodsA cross-sectional study was performed in a representative sample of mother–child pairs selected from 30 municipalities from November 2020 until October 2021. Iodine status [child urinary iodine concentration (UIC), maternal UIC, and breast milk iodine concentration (BMIC)] was measured. Child’s iodine intake was estimated using 2 24-h dietary recalls (24-HR) and a food frequency questionnaire. The Multiple Source Method was used to estimate the usual iodine intake distributions from the 24-HR assessments. ResultsThe median UIC in 333 children was 145 μg/L, indicating adequate iodine status according to the WHO cutoff (100 μg/L). The median usual iodine intake was 83 μg/d. Furthermore, 35% had suboptimal usual iodine intakes [below the proposed Estimated average requirement (72 μg/d)], whereas <1% had excessive usual iodine intakes [above the Upper intake level (200 μg/d)]. There was a positive correlation between children’s iodine intake and BMIC (Spearman rank correlation coefficient r = 0.67, P < 0.001), and between children’s UIC and BMIC (r = 0.43, P < 0.001), maternal UIC (r = 0.23, P = 0.001), and maternal iodine intake (r = 0.20, P = 0.004). ConclusionDespite a median UIC above the cutoff for iodine sufficiency, more than a third of the children had suboptimal usual iodine intakes. Our findings suggest that many children will benefit from iodine fortification and that risk of iodine excess in this age group is low.

The use of breast milk iodine concentration in the first week of lactation as a biomarker of iodine status in breast-feeding women.

Breast milk iodine concentration (BMIC) is a promising indicator of iodine status in lactating women. However, there are limited data on its usefulness to reflect maternal iodine deficiency. Therefore, the aim of our study was to assess iodine concentration in breast milk and urine samples in exclusively breast-feeding women. Eligible pregnant women undergoing routine antenatal care in a large hospital in Shaanxi Province, China, were followed up from the third trimester of pregnancy until the first week of lactation. Urine samples (20 ml) were collected during pregnancy and lactation. Iodine concentration in samples was measured based on Sandell-Kolthoff reaction. Breast milk samples (5 ml) were provided during lactation. A receiver operating curve (ROC) was constructed to determine the diagnostic performance of BMIC. An iodine-specific FFQ was completed twice during pregnancy and lactation. A total of 200 women completed the study. The overall median BMIC was 89 μg/l, indicating iodine sufficiency (i.e. BMIC reference range between 60 and 465 μg/l). Women reported similar median urinary iodine concentration (UIC) during pregnancy and lactation (112 and 113 μg/l, respectively), but their iodine status differed - mild-to-moderate iodine deficiency during pregnancy and iodine sufficiency during lactation. The ROC for BMIC using UIC as a reference standard was 0·755 (95 % CI: 0·644, 0·866). In conclusion, this study demonstrated that women were iodine sufficient in the first week of lactation as assessed by UIC, which was consistent with BMIC. These findings suggested that BMIC is a useful biomarker to assess iodine status in lactating women.

Estimation of appropriate dietary intake of iodine among lactating women in China based on iodine loss in breast milk.

Data on iodine loss in breast milk, which are critical for establishing the appropriate dietary iodine intake for lactating women, is currently limited. A study was conducted to assess iodine loss in breast milk among Chinese lactating women to estimate the appropriate dietary intake of iodine. A total of 54 pairs of healthy, lactating women and their infants aged 0-6months were recruited from Tianjin and Luoyang cities in China. A 4days infant weighing study was conducted to assess iodine loss in the breast milk of lactating women. Mothers were required to weigh and record their infants' body weights before and after each feeding for a 24h period from 8:00 am to 8:00 am. During the weighing study, 2812 breast milk samples and 216 24-h urine samples were collected from each lactating mother for four consecutive days. In addition, a 3days 24h dietary record, including salt weighing and drinking water samples collecting, was performed by each lactating mother to determine dietary iodine intake during the weighing study. The average dietary iodine intake of lactating women was 323 ± 80μg/d. The median breast milk iodine concentration and 24h urinary iodine concentration of lactating women were 154 (122-181) and 135 (104-172)μg/L, respectively. The mean volume of breast milk and the mean iodine loss in the breast milk of lactating women were 711 ± 157mL/d and 112 ± 47μg/d, respectively. The appropriate dietary intake of iodine among lactating Chinese women is approximately 260µg/d. Based on the iodine loss in breast milk (110μg/d) found in this study, and the estimated average requirement of iodine for adults, the appropriate dietary intake of iodine among lactating Chinese women is 260µg/d, which is higher than the 240μg/d recommended by the China Nutrition Science Congress in 2013.

Assessment of the Iodine Status of Lactating Women and Infants in Shanghai, China.

There is a risk of iodine deficiency among pregnant women in China. However, research on the iodine status of lactating women and infants is scarce. In this study, we aimed to evaluate the iodine status of lactating women and their infants and explore the relationship between breast milk iodine concentrations (BMICs) and urinary iodine concentrations (UICs). In total, 257 lactating women and their infants were recruited from the Shanghai Sixth People's Hospital East campus between May 2018 and May 2019. The BMIC and UIC were measured by inductively coupled plasma‒mass spectrometry (ICP‒MS). One-day 24-h dietary recall was used to determine the dietary intake of iodine. The mean dietary intake of iodine among the lactating women was 145.1μg/day, and 97.83% (n = 225) of the lactating women had a dietary iodine intake below 240μg/day. The median BMIC and UIC of the lactating women was 150.7μg/L (interquartile range, IQR 102.9, 205.5) and 110.0μg/L (IQR 65.8, 171.4), respectively, and the median UIC of the infants was 212.7μg/L (IQR 142.1, 320.6). The BMIC of lactating women who consumed iodized salt was significantly higher than that of lactating women who did not consume iodized salt (p = 0.015). The infants' UIC values were significantly correlated with the BMIC values (r = 0.597**, p < 0.001). The iodine nutritional status of lactating women and infants in Shanghai was generally sufficient according to the WHO's iodine nutritional status recommendation. The use of iodized salt was related to increasing dietary iodine intake and the BMIC. Improvements in BMICs have positive effects on the nutritional levels of iodine in infants.

A systematic review of the iodine concentration in milk from around the world

A systematic review of the iodine concentration in milk from around the world

Variations in Breast Milk Iodine Concentration over 24 h among Lactating Women in Northern China

BackgroundAdequate breast milk iodine concentration (BMIC) is essential for the growth and cognitive development of exclusively breastfed infants; however, data on variations in BMIC over 24 h are limited. ObjectiveWe aimed to explore in lactating women the variation in 24-h BMIC. MethodsThirty pairs of mothers and breastfed infants aged 0–6 mo were recruited from the cities of Tianjin and Luoyang, China. A 3-d 24-h dietary record, including salt intake, was performed to assess the dietary iodine intake of lactating women. Breast milk samples before and after each feeding for 24 h and 24-h urine samples were collected from the women for 3 d to estimate iodine excretion. A multivariate linear regression model was used to analyze the factors influencing BMIC. A total of 2658 breast milk samples and 90 24-h urine samples were collected. ResultsThe median BMIC and 24-h urine iodine concentration (UIC) of lactating women for a mean of 3.6 ± 1.48 mo were 158 μg/L and 137 μg/L, respectively. The interindividual variability of BMIC (35.1%) was higher than that observed within individuals (11.8%). The variation in BMIC showed a “V” shaped curve over 24 h. The median BMIC at 08:00−12:00 (137 μg/L) was significantly lower than that at 20:00−24:00 (163 μg/L) and 00:00−04:00 (164 μg/L). A progressively increasing curve was obtained for BMIC until it peaked at 20:00 and plateaued at a higher concentration from 20:00 to 04:00 than at 08:00−12:00 (all P < 0.05). BMIC was associated with dietary iodine intake (β: 0.366; 95% CI: 0.004, 0.018) and infant age (β: −0.432; 95% CI: −1.07, −0.322). ConclusionsOur study shows that the BMIC presents a “V” shaped curve over 24 h. We recommend that breast milk samples be collected between 08:00 and 12:00 for evaluation of the iodine status of lactating women.

Uberdermin is a new transdermal anti-mastitiс drug

The work on creating an iodine-containing preparation for transdermal use was completed, and its physicochemical properties, stability during long-term storage, local irritant effect, exfoliating ability, harmlessness for the body, therapeutic effectiveness for mastitis and udder diseases in cows were studied. The drug of the new generation – uberdermin- results from the interaction of polyiodbismuthsulfamide (PIVS) and dimethyl sulfoxide in a ratio of 10: 1. It is a pasty product of orange color, with a slight garlic smell and a bitter, astringent taste. The study of the physical stability of uberdermin lasted 12 months; he did not reveal significant changes in the controlled indicators (color, smell, taste, consistency, homogeneity, impurities). Cutaneous applications of uberdermin did not reveal an irritating effect of the drug on the glandular tissue of the udder of cows; this is confirmed by counting the number of somatic cells in milk and lysozyme titer. Skin resorptive capacity of uberdermin, visual control of the speed of its discoloration after an application was completed 2.3 times faster compared to PIVS. Control of the translocation of active components of uberdermin in the parenchyma of the mammary gland of lactating cows was based on changes in the concentration of molecular iodine in milk after applying the drug to the skin. of the udder. As it turned out, already 6 hours after its application in a therapeutic dose, the concentration of iodine in milk increased almost twice. Uberdermin showed relatively high antibacterial activity against all tested strains, but the advantages over PIVS are not obvious. Treatment of dry cows with purulent catarrhal mastitis by uberdermin ensured 100% recovery, and 2–3 applications of the drug were needed for the course of treatment; it is two times less than the pre-dry period. Research studies on using uberdermin for udder diseases (frostbite of the tips, bruises, wounds, skin cracks) indicate the prospects of thorough research in this direction.

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

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

Characteristics and predictors of breast milk iodine in exclusively breastfed infants: Results from a repeated-measures study of iodine metabolism.

The iodine supply of exclusively breastfed infants entirely depends upon breast milk. Changes in breast milk iodine affect infants' iodine nutritional status. This study aimed to comprehensively assess the characteristics and predictors of breast milk iodine concentration (BMIC). This 7-day iodine metabolism experiment was conducted in 25 exclusively breastfed mother-infant pairs. The duplicate portion method was used to measure the mother's daily iodine intake from foods and water, and maternal 24-h urine excretion was assessed. We recorded the number of breastfeeds per mother per day and collected breast milk samples before and after each feeding. The median [quartile (Q)1-Q3 range] of BMIC was 115 (86.7, 172) μg/L. The BMIC before breastfeeding was generally higher than that after breastfeeding. Time-sequential analysis found that morning BMIC was most highly correlated with the prior day's iodine intake. Breast milk samples taken in the afternoon or after midnight are closer to the median level of BMIC throughout the day. The number of breast milk samples needed to estimate the iodine level with 95% CI within precision ranges of ± 20% was 83 for a population, 9 for an individual, and 2 for an individual's single day. Maternal total iodine intake (TII) and urine iodine were significantly associated with BMIC. 24-h urinary iodine excretion (24-h UIE) was found to be the best predictive indicator for the BMIC (β = 0.71, 95% CI: 0.64, 0.79). BMIC is a constantly changing indicator and trended downward during each breastfeeding. Breast milk samples taken in the afternoon or after midnight are most representative. BMIC was significantly associated with recent iodine intake. Maternal 24-h UIE was the best predictor of BMIC.

Assessment of Iodine Concentration in Human Milk from Donors: Implications for Preterm Infants.

Preterm infants are particularly vulnerable to developing iodine deficiency. Donor human milk (DHM) is the preferred feeding option if the mother’s own milk (MOM) is not available, but information on DHM iodine concentration (DHMIC) is lacking. Hence, we aimed to assess DHMIC to further evaluate the adequacy of iodine provision in preterm infants. Finally, associations that might influence DHMIC were studied. In 113 donors, we measured iodine intake by evaluating dietary records for five consecutive days with the DIAL® Software. From the second day of dietary record, donors provided human milk samples (at least one per day) for four consecutive days. Daily human milk samples were analyzed for DHMIC. A DHMIC ≥ 200 µg/L was considered an adequate iodine content for preterm infants. DHMIC and urine iodine concentration (UIC) were determined using ICP-MS. In our study, 83.2% of donors had a full-term infant. Breastfeeding time range was 1.5–49.4 months. During the dietary record, 55.8% took iodine-containing supplements, providing 40–200 µg/day of iodine. The medians (p25, p75) UIC and DHMIC were 112.4 (75.8, 160.1) and 148.5 (97.6, 206.1) µg/L, respectively. In this iodine-sufficient population, 70% had a DHMIC of <200 µg/L. Donors’ intake of iodine-containing supplements was associated with higher DHMIC.