Current trends of 24-h urinary iodine excretion in German schoolchildren and the importance of iodised salt in processed foods

Worldwide, the iodisation of salt has clearly improved iodine status. In industrialised countries, iodised salt added to processed food contributes most to iodine supply. Yet it is unclear as to what extent changes in the latter may affect the iodine status of populations. Between 2004 and 2009, 24-h urinary iodine excretions (UIE) were repeatedly measured in 278 German children (6 to 12 years old) of the Dortmund Nutritional and Anthropometric Longitudinally Designed Study (n 707). Na excretion measurements and simultaneously collected 3-d weighed dietary records provided data on intakes of the most important dietary sources of iodine in the children's diet. Actual trends of UIE (2004-9) and contributions of relevant food groups were analysed by mixed linear regression models. Longitudinal regression analysis showed a plateau of UIE in 2004-6; afterwards, UIE significantly decreased till 2009 (P = 0·01; median 24-h UIE in 2004-6: 85·6 μg/d; 2009: 80·4 μg/d). Median urinary iodine concentration fell below the WHO criteria for iodine sufficiency of 100 μg/l in 2007-9. Salt, milk, fish and egg intake (g/d) were significant predictors of UIE (P < 0·005); and the main sources of iodine were salt and milk (48 and 38 %, respectively). The present data hint at a beginning deterioration in the iodine status of German schoolchildren. A decreased use of iodised salt in industrially produced foods may be one possible reason for this development. Because of the generally known risks for cognitive impairment due to even mild iodine deficits in children, a more widespread use of iodised salt, especially in industrially processed foods, has to be promoted.     

Sodium reduction and the correction of iodine intake in Belgium: Policy options

Many studies suggest that high salt intakes are related to high blood pressure and consequently cardiovascular diseases. In addition salt intake was found to be related with obesity, renal stones, osteoporosis and stomach cancer. Belgium, such as other European countries, is suffering from both salt intakes that are twice as high as the recommended intakes and mild iodine deficiency. No comprehensive strategy encompassing both public health problems has been developed. While specific salt reduction targets for processed foods are still under discussion using a consensus approach with industry, an agreement was signed between the bakery sector and the Ministry of Health in April 2009, to encourage and increase the use of iodised salt in the production of bread. Based on results of recent surveys on population iodine status it is advised not to currently revise iodine concentrations in salt in bread but to advocate for a higher percentage of bakers using iodised salt and to install a good monitoring system to control the percentage of bakers effectively using adequately iodised salt. With regard to salt reduction, it is of utmost importance that all companies contribute and harmonise the salt content of their products according to the lowest possible thresholds in a first step. In order to achieve this goal, it will be necessary, in addition to the consensus approach, to come up with at least some legislative tools such as a salt tax or mandatory labelling of foods exceeding a specific sodium concentration. Once salt reduction targets have been clearly defined in Belgium over the longer term, a legal framework should be set in place where iodine concentration in salt for the production of bread and household salt is strictly regulated by law, to avoid a large variability in the iodine content of salt brands consumed. In conclusion, it is possible to tackle salt reduction and iodine deficiency at the same time on the condition that the approach is coordinated and well monitored. All the interventions and measures taken should clearly include education and communication directed towards consumers, food producers, public health professionals, pharmacists, healthcare workers, and media representatives.     

Joint action on monitoring injuries in Europe (JAMIE)

Many studies suggest that high salt intakes are related to high blood pressure and consequently cardiovascular diseases. In addition salt intake was found to be related with obesity, renal stones, osteoporosis and stomach cancer. Belgium, such as other European countries, is suffering from both salt intakes that are twice as high as the recommended intakes and mild iodine deficiency. No comprehensive strategy encompassing both public health problems has been developed. While specific salt reduction targets for processed foods are still under discussion using a consensus approach with industry, an agreement was signed between the bakery sector and the Ministry of Health in April 2009, to encourage and increase the use of iodised salt in the production of bread. Based on results of recent surveys on population iodine status it is advised not to currently revise iodine concentrations in salt in bread but to advocate for a higher percentage of bakers using iodised salt and to install a good monitoring system to control the percentage of bakers effectively using adequately iodised salt. With regard to salt reduction, it is of utmost importance that all companies contribute and harmonise the salt content of their products according to the lowest possible thresholds in a first step. In order to achieve this goal, it will be necessary, in addition to the consensus approach, to come up with at least some legislative tools such as a salt tax or mandatory labelling of foods exceeding a specific sodium concentration. Once salt reduction targets have been clearly defined in Belgium over the longer term, a legal framework should be set in place where iodine concentration in salt for the production of bread and household salt is strictly regulated by law, to avoid a large variability in the iodine content of salt brands consumed. In conclusion, it is possible to tackle salt reduction and iodine deficiency at the same time on the condition that the approach is coordinated and well monitored. All the interventions and measures taken should clearly include education and communication directed towards consumers, food producers, public health professionals, pharmacists, healthcare workers, and media representatives.     

Adequate iodine intake of Slovenian adolescents is primarily attributed to excessive salt intake

In Slovenia, table salt iodization has been applied to combat iodine deficiency. Recently, we found that Slovenian adolescents attained iodine sufficiency (median urinary iodine concentration was 140 μg/L; prevalence of goiter was <1%). National data indicate that salt intake of Slovenian population is too high (150% above the recommended limit); therefore, we hypothesized that sufficient iodine intake in adolescents can be primarily attributed to excessive salt intake. In a cross-sectional study, we investigated iodine and salt intake in Slovenian adolescents as well as the contributions of different foods to their intake. We determined the iodine and salt intake of a national representative sample of 2581 adolescents, aged 14 to 17 years, using the Food Frequency Questionnaire (FFQ). The FFQ covered habitual diets over the past year, and 2485 (96%) adolescents completed a valid FFQ (1370 girls, 1115 boys). The iodine intake was 189.7 ± 2.6 μg/d (mean ± standard error of mean), well above the recommended 150 μg/d (P < .001). Table salt was by far the biggest dietary source of iodine and sodium for both sexes. Total salt intake (mean ± standard error of mean, 10.4 ± 0.2 g/d) significantly exceeded the upper World Health Organization limit (<5 g/d, P < .001), especially in boys (11.5 ± 0.3 vs 9.4 ± 0.2 g/d in girls, P < .001). The main food sources of salt were table salt (33%), bread (24%), salty snack products (10%), meat products (8%), fish products (6%), and milk (4%). Salt intake from foods, excluding table salt, was 6.9 g/d (67% of total salt intake). We conclude that although Slovenian adolescents are iodine sufficient, their salt intake, especially among boys, is too high. Several nutritional interventions are proposed to reduce total salt intake while ensuring adequate iodine intake.     

Jodversorgung bei Kindern und Jugendlichen

Background

Over the last 15 years, the supply of iodine has clearly improved in Germany.

Results

Infants, children and adolescents living in Germany were studied. Apart from the broad acceptance of iodised table salt in households, an increase in the use of iodised salt, especially by the food production industry (including bakers and butchers), which was boosted by a simplification of the food labelling decree for iodised salt almost 15 years ago, has had a strong impact. Additional increases in iodine status were brought about by clear increases in the iodine content of milk. Despite this, around 25% of children still appear to have daily intakes below the recommended values, as determined using the gold standard of 24-h urine iodine excretion. This corresponds to the at least moderately increased thyroid volumes in more than 25% of German children and adolescents, as recently reported.

Conclusions

Emerging problems, such as the highly variable and partly excessive iodine content in milk, gender differences in iodine requirements as well as the start of a reduction in the use of iodized salt by bakers and butchers, are also discussed.     

An evaluation of salt intake and iodine nutrition in a rural and urban area of the C?te d'Ivoire.

OBJECTIVE: To evaluate the habitual salt intake of individuals living in the C?te d'Ivoire, and to monitor the iodine nutrition of adults, schoolchildren and pregnant women one year after implementation of a universal salt iodisation programme. DESIGN: A three day weighed food records with estimation of food intake from a shared bowl based on changes on body weight, determination of sodium and iodine concentrations in 24 h (24 h) urine samples from adults, and determination of urinary iodine in spot urines from schoolchildren and pregnant women. SETTING: A large coastal city (Abidjan) and a cluster of inland villages in the northern savannah region of the C?te d'Ivoire. SUBJECTS: For the food records: 188 subjects (children and adults) in the northern villages; for the 24 h urine collections: 52 adults in Abidjan and 51 adults in the northern villages; for the spot urine collections: 110 children and 72 pregnant women in Abidjan and 104 children and 66 pregnant women in the north. MAIN RESULTS: From the food survey data in the north, the total mean salt intake (s.d.) of all age groups and the adults was estimated to be 5.7 g/d (+/- 3.0), and 6.8 g/d (+/- 3.2), respectively. In the 24 h urine samples from adults, the mean sodium excretion was 2.9 g/d (+/- 1.9) in the north and 3.0 g/d (+/- 1.3) in Abidjan, corresponding to an intake of 7.3-7.5 g/d of sodium chloride. In the north the median 24 h urinary iodine excretion in adults was 163 microg/d, and the median urinary iodine in spot urines from children and pregnant women was 263 microg/l and 133 microg/l, respectively. In contrast, in Abidjan the median 24 h urinary iodine was 442 microg/d, with 40% of the subjects excreting > 500 microg/d, and the median urinary iodine in spot urines from children and pregnant women was 488 microg/l and 364 microg/l, respectively. Nearly half of the children in Abidjan and 32% of the pregnant women were excreting > 500 microg/l. CONCLUSION: Based on the estimates of salt intake in this study, an optimal iodine level for salt (at the point of consumption) would be 30 ppm. Therefore the current goals for the iodised salt programme--30-50 ppm iodine appear to be appropriate. However, in adults, children and pregnant women from Abidjan, high urinary iodine levels--levels potentially associated with increased risk of iodine-induced hyperthyroidism--are common. These results suggest an urgent need for improved monitoring and surveillance of the current salt iodisation programme in the C?te d'Ivoire.     

中国非高碘地区人群膳食碘摄入量评估

目的评估中国非高碘地区(水碘含量<150μg/L)人群膳食碘摄入量不足的潜在风险。方法利用中国营养与健康状况调查资料、食盐消费量数据和饮用水推荐摄入量,以及中国食物成分表及盐碘和水碘监测数据,估计我国非高碘地区13个性别-年龄组人群在食用加碘食盐和不加碘食盐情形下的膳食碘摄入量,并与我国的膳食碘摄入量推荐标准进行比较。结果在非高碘地区食用加碘盐情况下,虽然人群的平均碘摄入量均高于推荐摄入量(RNI),但碘摄入量超过最高耐受摄入量(UL)的比例平均为5.8%,而低于RNI的比例平均为13.4%,并且18岁以上成人(含孕妇和乳母)低于平均需要量(EAR)的比例为9.4%,且食盐对膳食碘的贡献率远高于饮用水和各类食物;在非高碘地区食用不加碘盐的情况下,虽然多数性别-年龄组人群的平均碘摄入量高于RNI,但摄入量低于RNI的平均比例高达97.6%,其中18岁以上成人(含孕妇和乳母)低于EAR的比例为97.4%,且各类食物合并的平均碘贡献率高于饮用水。结论中国非高碘地区居民碘缺乏的健康风险大于碘过量的健康风险,这在食用不加碘食盐的情况下尤为明显;加碘食盐应当是非高碘地区居民膳食碘的最主要来源。     

关于成人碘安全摄入量的探讨

目的探讨成人碘的安全摄入量。方法选择甲状腺功能正常的(22.54±2.65岁)健康志愿者。随机分为7组,各组每人每日分别服用500,750,1000,1250,1500,1750,2000μg的碘剂,为期4w。于实验前、实验第2w以及实验结束时分别采集志愿者空腹血、晨尿。用化学发光免疫分析法测定血清FT4、灵敏促甲状腺激素(sTSH),定量放免法测定甲状腺过氧化物酶抗体(thyroid peroxidase antibody,TPOAb)、甲状腺球蛋白抗体(thyroglobulin antibody,TGAb)浓度,用砷铈氧化还原法测定尿碘水平。对被调查者进行为期7 d的膳食调查。采集天津市市售食物、饮用水样品,以及食盐样品,测定其碘含量。结果补碘前人群碘摄入水平充足,尿碘中位数为272.25μg/L,被调查者膳食碘摄入的平均值(含碘盐)为346.24μg/d。与补充碘剂前相比,补碘后各组人群尿碘水平明显增加;血清FT4在正常值范围内下降;各组人群在补充碘剂2 w后血清sTSH明显上升,与补碘前相比增加近1倍多,至4 w后增加近2倍。各剂量组间相比血清sTSH变化幅度基本一致。正常人群补充500～2000μg碘剂2 w后出现了亚临床甲状腺功能减退,各剂量组的发病率在15.00%~47.37%之间。试验结束时未见临床甲减患者。结论正常人群补充500μg/d碘即可引起亚临床甲状腺功能减退。因此,对于生活在碘营养充足地区的人群每日碘的补充剂量不宜超过500μg,结合每日膳食碘的摄入量,我们建议碘的可耐受的最高摄入量(UL)的上限值应低于900μg。     

Iodine status in Melbourne adults in the early 1990s and 2007-08

Objective: To investigate the iodine status of Melbourne adults in 1992–94 and 2007–08, and to assess dietary iodine intake to enable comparison with recommended Nutrient Reference Values. Method: A cross‐sectional study utilising 24‐hr urine samples collected at two time points in a random sample of the Melbourne Collaborative Cohort Study. Two hundred and fifty seven adults (128 males, 129 females) in 1992–94, with a mean age of 56 years, and 265 adults (132 males, 133 females) in 2007–08, with a mean age of 68 years, were assessed, all being Melbourne residents. Urinary iodine concentration (UIC) was determined and daily urinary iodine excretion and daily iodine intake were assessed. Results: In 1992–94, the median UIC was 27 μg/L and 84% had UIC <50 μg/L. The median daily iodine intake was 51 μg/d, and 83% of participants had dietary iodine intakes below the Estimated Average Requirement of 100 μg/d. In 2007–08, the median UIC was 49 μg/L, 51% had UIC <50 μg/L and the median daily iodine intake was 98 μg/d, with 52% of intakes below the EAR. Conclusion: Melbourne adults were moderately iodine deficient in 1992–94, and borderline moderately deficient in 2007–08. Implications: While iodine status appears to have improved, it remains below an adequate level for much of the adult population of Victoria. Adequate monitoring is fundamental to assess whether the mandatory use of iodised salt in bread is effective in reducing iodine deficiency across all population groups.     

Consumption of plant sterols in Belgium: consumption patterns of plant sterol-enriched foods in Flanders, Belgium

The present study describes the consumption of foods enriched with plant sterols (PS) and supplements containing PS, and evaluates PS intakes via the current consumption and for specific consumption scenarios. A market inventory was performed to collate different PS-enriched food items and supplements available in Belgium. An FFQ was developed to investigate the consumption of PS-enriched foods and supplements. A total of 139 pre-school children (2·5-7 years old) and 569 adults (308 women and 261 men) living in Flanders (the northern, Dutch-speaking part of Belgium) participated in the study. Of these, 21 % (Flemish pre-school children) and 28·5 % (Flemish adults) consume PS-enriched food products, leading to a mean PS intake in the consumer group of 0·70 (sd 0·61) g/d for pre-school children and 1·51 (sd 1·42) g/d for adults. Of the adult PS consumers, 23·2 % did not suffer from elevated blood cholesterol levels; 50 % of them had a PS intake less than or equal to 1 g/d and 16·4 % had a PS intake above 3 g/d and 7·8 % even had an intake above 4 g/d. Scenario studies assessed the intake when all Belgian adults would consume PS-enriched margarines without (scenario 1) or with (scenario 2) a daily consumption of a PS-enriched yoghurt drink. This resulted in an intake above 3 g/d in 17 % (women) and 29 % (men) for scenario 1 and 40 % (women) and 53 % (men) for scenario 2. The results indicate that PS-enriched food products are also consumed by the non-target group. Efficient communication tools are needed to inform consumers better about the target group of PS-enriched products, the advised dose per day and alternative dietary strategies to lower the blood cholesterol level.     

Cereal fibre intake in Australia: a cross-sectional analysis of the 2011–12 National Nutrition and Physical Activity Survey

Extensive evidence supports health benefits of cereal fibre, however globally no national intake data exists. This study aimed to determine estimates of intake and food sources of cereal fibre, and relationships to dietary fibre intake in an Australian sample population. A cereal fibre database was applied to dietary intake data from the 2011–12 National Nutrition and Physical Activity Survey (n?=?12,153). Usual intake based on 2-day intake data was weighted to infer population results. Median daily cereal fibre intake was 6.4?g/d (9.7?g/10?MJ/d) for adults (19–85?years) and 6.2?g/d (10.2?g/10?MJ/d) for children/adolescents (2–18?years). Individuals with the highest cereal fibre intake were more likely to meet dietary fibre recommendations than those with the lowest intake (males Q4: 17.1% Q1: 3.9%; females Q4: 20.3% Q1: 6.6%). Breakfast cereals, bread and bread rolls provided the most cereal fibre. This study provides first quantification of cereal fibre from all sources in an Australian national sample.     

Iodine status in preschool children and evaluation of major dietary iodine sources: a German experience

Purpose

Even mild iodine deficiency may negatively affect cognitive performance, especially at a young age. Our aim was to investigate iodine status in very young children and to assess the importance of iodized salt in processed foods of which the use has decreased during the last years in Germany.

Methods

Twenty-four hours urinary iodine excretion (UIE) as a marker of iodine intake was measured in 378 24 h urine samples collected 2003–2010 by 221 3 to <6 years old participants of the DONALD Study. Parallel 3-d weighed dietary records and measurements of urinary sodium excretion provided data on the daily consumption of the most important iodine sources in the children’s diet (iodized salt, milk, fish, meat and eggs). Time trends of UIE (2003–2010) and contributions of the different food groups were analyzed by using linear mixed-effects regression models.

Results

Median UIE of 71 μg/d in boys and 65 μg/d in girls (P = 0.03), corresponding to an iodine intake of 82 and 75 μg/d, respectively (assumption: 15 % non-renal iodine losses), was below the recommended dietary allowance (RDA) of 90 μg/d. Milk, salt and egg intake were significant predictors of UIE; milk and salt together accounted for >80 % of iodine supply. Between 2003 and 2010, UIE decreased significantly by approximately 1 μg/d per year. The contribution of salt intake to UIE decreased from 2003–2006 to 2007–2010.

Conclusion

In countries where salt is a major iodine source, already modest decreases in the iodized proportion of salt used in processed foods may relevantly impair iodine status even in preschool children.     

Iodine content in bread and salt in Denmark after iodization and the influence on iodine intake

Objective To measure the iodine content in bread and household salt in Denmark after mandatory iodine fortification was introduced and to estimate the increase in iodine intake due to the fortification.

Design The iodine content in rye breads, wheat breads and salt samples was assessed. The increase in iodine intake from fortification of bread and the increase in total iodine intake after fortification were estimated.

Subjects Iodine intake before and after fortification was estimated based on dietary intake data from 4,124 randomly selected Danish subjects.

Main results Approximately 98% of the rye breads and 90% of the wheat breads were iodized. The median iodine intake from bread increased by 25 (13–43) µg/day and the total median iodine intake increased by 63 (36–104) µg/day.

Conclusions The fortification of bread and salt has resulted in a desirable increase in iodine intake, and the current fortification level of salt (13 ppm) seems reasonable.     

Dietary sources of energy and macronutrient intakes among Flemish preschoolers

This study aims to identify major food sources of energy and macronutrients among Flemish preschoolers as a basis for evaluating dietary guidelines. Three-day estimated diet records were collected from a representative sample of 696 Flemish preschoolers (2.5-6.5 years old; participation response rate: 50%). For 11 dietary constituents, the contribution of 57 food groups was computed by summing the amount provided by the food group for all individuals divided by the total intake of the respective nutrient for all individuals. Bread (12%), sweet snacks (12%), milk (6%), flavoured milk drinks (9%), and meat products (6%) were the top five energy contributors. Sweet snacks were among the top contributors to energy, total fat, all fatty acids, cholesterol, and complex and simple carbohydrates. Fruit juices and flavoured milk drinks are the main contributors to simple carbohydrates (respectively 14% and 18%). All principal food groups like water, bread and cereals, vegetables, fruit, milk and spreadable fats were under-consumed by more than 30% of the population, while the food groups that were over-consumed consisted only of low nutritious and high energy dense foods (sweet snacks, sugared drinks, fried potatoes, sauces and sweet spreads). From the major food sources and gaps in nutrient and food intakes, some recommendations to pursue the nutritional goals could be drawn: the intake of sweet snacks and sugar-rich drinks (incl. fruit juices) should be discouraged, while consumption of fruits, vegetables, water, bread and margarine on bread should be encouraged.     

浙江省丽水市孕产妇碘营养状况及与婴幼儿生长发育的相关性

[目的]了解浙江省丽水市孕产妇的碘营养情况及孕产妇碘缺乏与婴幼儿生长发育的相关性.[方法]采用分层抽样法抽取2017年1月—2018年12月丽水市莲都区孕妇209例,检测孕妇的尿碘水平以及家中食盐碘含量,分析孕妇碘缺乏的影响因素.对孕妇生产的婴儿进行1年随访,进行代谢性疾病筛查和体格检查,评估生长发育情况.[结果]20...     

Consumption of plant sterols in Belgium: estimated intakes and sources of naturally occurring plant sterols and β-carotene

The objective of the present study was to assess the intake of naturally occurring plant sterols and β-carotene via the overall diet of Belgian pre-school children and adults. Two different Belgian food consumption databases were used: (1) one with consumption data of pre-school children (2·5-6·5 years old) and (2) one with consumption data of adults ( ≥ 15 years old). These consumption data were combined with a newly developed database containing the plant sterol and β-carotene content in all relevant food items based on international food composition databases and scientific literature. The results show that Flemish pre-school children have a median plant sterol intake of 172 (interquartile range (IQR) = 47) and 184 (IQR = 52) mg/d for girls and boys, respectively. Their median β-carotene intake was 1857 (IQR = 1250) μg/d, without significant difference between girls and boys. Belgian women and men have a median plant sterol intake of 218 (IQR = 113) and 280 (IQR = 158) mg/d, respectively, and a median β-carotene intake of 2086 (IQR = 1254) μg/d (not significantly different between the sexes). The main food source of naturally occurring plant sterols was bread and other cereal products. For β-carotene, the main food source was vegetables.     

Variable iodine intake persists in the context of universal salt iodization in china

Iodine deficiency disorders were prevalent in China until the introduction of universal salt iodization in 1995. Concerns have recently arisen about possible excess iodine intake in this context. To document iodine intake and the contribution from iodized salt in China, we surveyed dietary iodine intake during China's nationally representative 2007 total diet study (TDS) and during an additional TDS in 4 coastal provinces and Beijing in 2009. Iodine intake was broken down by age and sex in 2009. Mean daily iodine and salt intake and the contribution from different food and beverage groups (and in 2009, individual items) was measured. The iodine in food cooked with iodized and noniodized salt was also assessed. The mean calculated iodine intake of a standard male in China was 425 μg/d in 2007 and 325 μg/d in coastal areas in 2009, well below the upper limit (UL) in all provinces. In 2009, iodine intake was above the UL in only 1-7% of age-sex groups, except among children (18-19%). A concerning number of individuals consumed less than the WHO-recommended daily allowance, including 31.5% of adult women. Salt contributed 63.5% of food iodine, and 24.6% of salt iodine was lost in cooking. Overall salt consumption declined between the surveys. Salt iodization assures iodine nutrition in China where environmental iodine is widely lacking. The risk of iodine excess is low, but planned decreases in salt iodization levels may increase the existing risk of inadequate intake. Regular monitoring of urinary iodine and more research on the impact of excess iodine intake is recommended.     

Iodine content in bread and salt in Denmark after iodization and the influence on iodine intake

OBJECTIVE: To measure the iodine content in bread and household salt in Denmark after mandatory iodine fortification was introduced and to estimate the increase in iodine intake due to the fortification. DESIGN: The iodine content in rye breads, wheat breads and salt samples was assessed. The increase in iodine intake from fortification of bread and the increase in total iodine intake after fortification were estimated. SUBJECTS: Iodine intake before and after fortification was estimated based on dietary intake data from 4,124 randomly selected Danish subjects. MAIN RESULTS: Approximately 98% of the rye breads and 90% of the wheat breads were iodized. The median iodine intake from bread increased by 25 (13-43) microg/day and the total median iodine intake increased by 63 (36-104) microg/day. CONCLUSIONS: The fortification of bread and salt has resulted in a desirable increase in iodine intake, and the current fortification level of salt (13 ppm) seems reasonable.