Relationship between salt consumption and iodine intake in a pediatric population

Iodine Status and Its Influencing Factors in Hospitalized and Healthy Preschool-Age Children

Iodine is a trace element necessary for synthesizing thyroid hormones. It is especially crucial for the neurodevelopment and intellectual development of children. Preschool-age children admitted to the hospital tend to have more fragile physical and mental health, but few studies demonstrate their iodine status. Our study aimed to investigate the iodine status of hospitalized and healthy preschool-age children and to explore the factors influencing them. From January to December 2021, 426 children aged 3-6 years were admitted to the respiratory department for pneumonia, bronchopneumonia, or bronchiectasis, but they could eat normally and were recruited as hospitalized children. Six hundred ten healthy children aged 3-6 years were included. We collected anthropometric measurements and urine samples from hospitalized and healthy preschool-age children, and iodine status was assessed through urinary iodine concentration (UIC) and urinary iodine/creatinine ratio (UI/Cr). UIC was 40.1 and 166.1 µg/L for hospitalized and healthy preschool-age children, respectively (P < 0.001). Urinary creatinine concentration (UCr) was 0.2 and 0.8 g/L for hospitalized and healthy preschool-age children, respectively (P < 0.001). UIC decreased with increasing height z-scores in hospitalized children (Spearman's rho = -0.11, P = 0.022). A significantly increased risk of UIC < 100 µg/L was found in hospitalized children (OR = 9.1 (6.8, 12.2), P < 0.001) when compared to healthy children. In conclusion, hospitalized preschool-age children are likelier to have iodine insufficiency than healthy preschool-age children, especially those with good linear growth. Measures should be implemented to ensure adequate iodine intake of preschool-age children during hospitalization to avoid affecting their intellectual and physical development. Due to lower UCr in hospitalized children, creatinine is not appropriate for assessing iodine status in hospitalized children.

Iodine Nutrition Status of Children Aged 3-13 Years in Areas with High Groundwater Iodine Content in China

BACKGROUND

Adequate iodine status is crucial for children's health and normal development. However, there is a paucity of research on the iodine status of children from areas with high groundwater iodine content.

OBJECTIVES

The objectives of this were to monitor the iodine status of children in Shandong, China (regions primarily characterized by high iodine concentrations in groundwater) and describe the factors influencing children's iodine status.

METHODS

A cross-sectional study was conducted from 2013 to 2023 on 3253 3- to 13-y-old children. We collected drinking water, spot urine, and 24-h urine samples from children to assess their iodine status [measuring drinking water iodine concentration (WIC), water iodine intake (WII), urine iodine concentration (UIC), 24-h urine iodine excretion (24-h UIE), daily iodine intake (DII), etc.], and analyzed influencing factors.

RESULTS

The median WIC for children was 183 (IQR: 70.2, 362) μg/L, and the median spot UIC was 428 (IQR: 194, 737) μg/L, surpassing the WHO cutoff (300 μg/L). Children at risk of iodine excess numbered 1750 (61.8%). Approximately 61% of iodine intake came from drinking water. Boys had significantly higher iodine intake than girls (P < 0.001). Children's age showed positive correlations with spot UIC, 24-h UIC, and 24-h UIE. There were no significant differences in 24-h UIC and 24-h UIE among children with different BMIs. The logistic regression model revealed that the risk of iodine excess was increased by boy gender, increment in age (OR: 1.05; 95% CI: 1.02, 1.08), and every 10 μg (OR: 1.04; 95% CI: 1.03, 1.04) or 50 μg (OR: 1.19; 95% CI: 1.16, 1.22) increment in WII.

CONCLUSIONS

Children in areas with high groundwater iodine content are at a risk of iodine excess. As age increases, the risk of iodine excess in children rises, with boys at a higher risk than girls.

Household Salt consumption and urinary iodine levels in Schoolchildren aged 8-10 in Darab City, Iran: 2022

Iodized salt serves as an effective intervention strategy, combating iodine deficiency disorders (IDD) and promoting overall health. This study aimed to assess the household salt consumption status and its relationship with urinary iodine (UI) levels among school-aged children. This is a descriptive-cross-sectional study that was selected by cluster-random sampling from 5 girls' schools (182) and 5 boys' schools (169), with a total of 351 primary school students (8-10 years old) of Darab. To explore the relationship between independent variables and dependent variable, urinary iodine (UI) levels, linear regression model was applied. A significance level of 0.05 was adopted for all analyses. The median UI level was 138 µg/L (IQR = 111). Our findings revealed that 66% of used iodized salt. A significant majority of participants properly stored their salt in containers with lids. Nearly half of the students in Darab have insufficient iodine intake. Despite controlling for the effect of iodized foods consumption, no significant association (P-value = 0.693) was observed between the storage method and iodized foods. Our study showed that students do not receive enough iodine or have received more than the required amount of iodine. Therefore, efforts should be focused on increasing awareness of diseases caused by iodine deficiency.

Assessment of Salt, Potassium, and Iodine Intake in the Croatian Adult Population Using 24 h Urinary Collection: The EH-UH 2 Study

Cardiovascular diseases, which are the leading cause of death in Croatia, are linked to the high prevalence of hypertension. Both are associated with high salt intake, which was determined almost two decades ago when Croatian Action on Salt and Health (CRASH) was launched. The main objective of the present study was to evaluate salt, potassium, and iodine intake using a single 24 h urine sample in a random sample of the adult Croatian population and to analyse trends in salt consumption after the CRASH was intensively started.

METHODS

In this study, we analysed data on 1067 adult participants (mean age 57.12 (SD 13.9), men 35%).

RESULTS

Mean salt and potassium intakes were 8.6 g/day (IQR 6.2-11.2) and 2.8 g/day (IQR 2.1-3.5), respectively, with a sodium-to-potassium ratio of 2.6 (IQR 1.8-3.3). We detected a decrease of 17.6% (2 g/day less) in salt consumption compared with our previous salt-mapping study. However, only 13.7% and 8.9% met the WHO salt and potassium recommended targets of 5 g/day and 3.5 g/day, respectively. Salt intake was higher, and potassium ingestion was lower, in rural vs. urban regions and in continental vs. Mediterranean parts of Croatia. Moderate to severe iodine insufficiency was determined in only 3% of the adult participants.

CONCLUSION

In the last fifteen years, salt consumption has been significantly reduced in the Croatian adult population because of the intensive and broad CRASH program. However, salt intake is still too high, and potassium ingestion is too low. Salt reduction programs are the most cost-effective methods of cardiovascular disease prevention and merit greater consideration by the government and health policy makers.

The Role of Nutrition on Thyroid Function

Thyroid function is closely linked to nutrition through the diet-gut-thyroid axis. This narrative review highlights the influence of nutritional components and micronutrients on thyroid development and function, as well as on the gut microbiota. Micronutrients such as iodine, selenium, iron, zinc, copper, magnesium, vitamin A, and vitamin B12 influence thyroid hormone synthesis and regulation throughout life. Dietary changes can alter the gut microbiota, leading not just to dysbiosis and micronutrient deficiency but also to changes in thyroid function through immunological regulation, nutrient absorption, and epigenetic changes. Nutritional imbalance can lead to thyroid dysfunction and/or disorders, such as hypothyroidism and hyperthyroidism, and possibly contribute to autoimmune thyroid diseases and thyroid cancer, yet controversial issues. Understanding these relationships is important to rationalize a balanced diet rich in essential micronutrients for maintaining thyroid health and preventing thyroid-related diseases. The synthetic comprehensive overview of current knowledge shows the importance of micronutrients and gut microbiota for thyroid function and uncovers potential gaps that require further investigation.

Mineral content in commercially branded and local salt in selected villages from Bahi, Iramba, Manyoni, and Singida urban districts, Tanzania

The study examines the mineral content of table salts used by households in villages adjacent to the production areas. A total of 210 samples from commercial and local salts were collected, and analyzed using iodometry titration, spectrophotometry, colorimetry, and atomic absorption spectroscopy (AAS) techniques, followed by a household interview for salt type preference. The lowest detectable concentration LOD, lowest quantifiable concentration LOQ and, recovery of methods ranged (0.32-2.155 μg/kg), (0.117-6.387 μg/kg) and, (94.2-103.6 %), respectively. Significant differences in mineral contents were observed within and between local and commercially branded salts (p < 0.001). The mean iodine in the local salt samples from Kitangiri (SA), Singidani (SB), Kindai (SC), Chibumagwa (SD), and Sulunga (SE) ranged from 10.5 ± 0,02 to 16.9 ± 0.01 mg/Kg, with only SA and SC in the World Health Organization (WHO) limits, while commercially branded salt samples SF (Malindi), and SG (Dar es salaam) ranged from 23.4 ± 0.01 to 35.9 ± 0,02 mg/kg that were in the Tanzania Bureau of Standards (TBS) and WHO agreed range. Other ions recorded were nitrate (3.3-4.4 mg/kg, 5.45-7.40 mg/kg), phosphate (0.02-0.48 mg/kg, 0.03 mg/kg), sulphate (0.31-0.42 mg/kg, 0.03-0.07 mg/kg), ammonia (0.5 mg/kg, 0.5 mg/kg to 0.6 mg/kg), copper (1.0-2.0 mg/kg, 0.9-2.0 mg/kg), iron (0.5-1.8 mg/kg, 0.9 mg/kg), and manganese (0.5-1.8 mg/kg, 0.9 mg/kg) for local and commercially branded salt, respectively. Households preferred local to commercial-branded salts: Nkonkilangi 163 (69.9, 32.1 %), Mangwanjuki 96 (17.2, 82.8 %), Unyanga 54 (26.7, 73.3 %), Chibumagwa 106 (63.0, 37.0 %), and Chali Igongo 51 (74.6, 25.4 %), respectively. Public health interventions are recommended to promote the consumption of adequately iodized salt for informed dietary choices.

The Future for the Children of Tomorrow: Avoiding Salt in the First 1000 Days

It is widely known that optimal nutrition in the first 1000 days of life positively impacts the child's development throughout adulthood. In this setting, salt should not be added to complementary feeding. In developed countries, salt intake is generally higher than recommended for children. Excessive salt intake is the major determinant of hypertension and is associated with several cardiovascular outcomes. Therefore, pediatricians have a key role in raising awareness among parents to avoid salt consumption in the first 1000 days of life to ensure better health for their children. Starting from a review of the literature published in PubMed/MedLine regarding the short- and long-term consequences of salt consumption during the first 1000 days of life, our comprehensive review aims to analyze the beneficial effects of avoiding salt at such a vulnerable stage of life as the first 1000 days. Obesity, hypertension, increased salt sensitivity, high sweet drink consumption, increased mortality, and morbidity persisting in adult age represent the principal consequences of a higher salt intake during the first 1000 days of life.

Eater-oriented knowledge framework for reducing salt and dietary sodium intake (scoping review)

Salt and dietary sodium are ubiquitously present in daily food practices and, at the same time, reducing salt intake presents an important public health issue. Given such an ambivalent position of salt in human diet, we argue that public health guidelines toward dietary sodium reduction require an eater-oriented knowledge framework. In this article we are making the first steps toward a flexible interdisciplinary database which would include nutritional, socio-economic, cultural, material, and socio-psychological determinants of salt consumption for comprehensive public health campaigns. We employ an explorative scoping review of academic articles and reports, limiting our review to the original data on salt or sodium consumption published in English or French between 2000 and 2022. We describe salt consumption as research object, identifying its representation in different research fields, data sources, methodologies, samples, and links with nutritional recommendations. We synthesize existing approaches via four eater-oriented categories: Socio-demographic and cultural descriptors of salt consumers; Knowledge, attitudes, and beliefs on nutritional norms; Salt practices associated with dietary or medical regimes; Salt materialities: interactions and contexts. In each category, we identify the dominant relational features, i.e., what kind of 'eater-salt' relation is being put forward. We thus build an interdisciplinary documentary base of dietary sodium consumption factors. We discuss the results, suggesting that comprehensive nutritional policies for global salt reduction require interdisciplinary eater-oriented data frameworks.

The effect of sodium restriction on iodine prophylaxis: a review

PURPOSE

Sodium is essential to life. However, its dietary excess is detrimental to the cardiovascular system, and sodium restriction is a crucial step in cardiovascular prevention. Iodine deficiency has been fought worldwide for decades, and substantial success has been achieved introducing the use of iodine-enriched salt. Nevertheless, areas of iodine deficiency persist around the world, both in developing and industrialized countries, and a major concern affecting dietary sodium reduction programs is represented by a possible iodine intake deficiency. There are substantial differences in the source of alimentary iodine among countries, such as iodized salt added, household tap water, seafood, or salt employed in packaged food. It is clear that a sodium-restricted diet can induce differences in terms of iodine intake, depending on the country considered. Moreover, iodine status has undergone relevant changes in many countries in the last years.

METHODS

Systematic review of literature evidence about the possible effects of sodium restriction on population iodine status.

RESULTS

To date, the available results are conflicting, depending on country, salt iodization policy, as well as time frame of data collection. However, to ensure an optimal iodine supply by salt fortification, without exceeding the current recommendation by World Health Organization for salt intake, seems to be an achievable goal.

CONCLUSION

A balanced approach may be obtained by an adequate iodine concentration in fortified salt and by promoting the availability of iodized salt for household consumption and food industry use. In this scenario, updated prospective studies are strongly needed.

The burden and trend of gastric cancer and possible risk factors in five Asian countries from 1990 to 2019

The burdens and trends of gastric cancer are poorly understood, especially in high-prevalence countries. Based on the Global Burden of Disease Study 2019, we analyzed the incidence, death, and possible risk factors of gastric cancer in five Asian countries, in relation to year, age, sex, and sociodemographic index. The annual percentage change was calculated to estimate the trends in age-standardized incidence rate (ASIR) and age-standardized death rate (ASDR). The highest ASIR per 100,000 person-years in 2019 was in Mongolia [44 (95% uncertainty interval (UI), 34 to 55)], while the lowest was in the Democratic People's Republic of Korea (DPRK) [23 (95% UI, 19 to 29)]. The highest ASDR per 100,000 person-years was in Mongolia [46 (95% UI, 37 to 57)], while the lowest was in Japan [14 (95% UI, 12 to 15)]. Despite the increase in the absolute number of cases and deaths from 1990 to 2019, the ASIRs and ASDRs in all five countries decreased with time and improved sociodemographic index but increased with age. Smoking and a high-sodium diet were two possible risk factors for gastric cancer. In 2019, the proportion of age-standardized disability-adjusted life-years attributable to smoking was highest in Japan [23% (95% UI, 19 to 28%)], and the proportions attributable to a high-sodium diet were highest in China [8.8% (95% UI, 0.21 to 33%)], DPRK, and the Republic of Korea. There are substantial variations in the incidence and death of gastric cancer in the five studied Asian countries. This study may be crucial in helping policymakers to make better decisions and allocate appropriate resources.

Iodine Requirements in Pediatrics: From Fetal Life to Adolescence

The aim of this mini-review is to present the current knowledge on iodine requirements in developmental age, from conception to adolescence. It is based on the analysis of updated national and international guidelines on iodine intake and the prevention of iodine deficiency. Health policy initiatives carried out in industrialized countries in previous decades have led to a dramatic improvement in nutritional iodine status in the general population. However, the prevention of iodine deficit continues to be a concern, especially for vulnerable categories, like adolescents and pregnant women.

Iodine Intake from Food and Iodized Salt as Related to Dietary Salt Consumption in the Italian Adult General Population

Since the Italian iodoprophylaxis strategy is based on the use of iodized salt, we assessed the relationship between dietary salt consumption and iodine intake in the Italian adult population. We estimated the relative contribution given by the use of iodized salt and by the iodine introduced by foods to the total iodine intake. The study population included 2219 adults aged 25-79 years (1138 men and 1081 women) from all Italian regions, participating to the Osservatorio Epidemiologico Cardiovascolare/Health Examination Survey 2008-2012 (OEC/HES), and examined for sodium and iodine intake in the framework of the MINISAL-GIRCSI Programme. Dietary sodium and total iodine intake were assessed by the measurement of 24 h urinary excretion, while the EPIC questionnaire was used to evaluate the iodine intake from food. Sodium and iodine intake were significantly and directly associated, upon accounting for age, sex, and BMI (Spearman rho = 0.298; p < 0.001). The iodine intake increased gradually across quintiles of salt consumption in both men and women (p < 0.001). The European Food Safety Authority (EFSA) adequacy level for iodine intake was met by men, but not women, only in the highest quintile of salt consumption. We estimated that approximately 57% of the iodine intake is derived from food and 43% from salt. Iodized salt contributed 24% of the total salt intake, including both discretionary and non-discretionary salt consumption. In conclusion, in this random sample of the Italian general adult population examined in 2008-2012, the total iodine intake secured by iodized salt and the iodine provision by food was insufficient to meet the EFSA adequate iodine intake.