Overview of Selenium Deficiency and Toxicity Worldwide: Affected Areas, Selenium-Related Health Issues, and Case Studies

Burden of selenium deficiency and cost-effectiveness of selenium agronomic biofortification of staple cereals in Ethiopia

Selenium (Se) deficiency among populations in Ethiopia is consistent with low concentrations of Se in soil and crops that could be addressed partly by Se-enriched fertilisers. This study examines the disease burden of Se deficiency in Ethiopia and evaluates the cost-effectiveness of Se agronomic biofortification. A disability-adjusted life years (DALY) framework was used, considering goiter, anaemia, and cognitive dysfunction among children and women. The potential efficiency of Se agronomic biofortification was calculated from baseline crop composition and response to Se fertilisers based on an application of 10 g/ha Se fertiliser under optimistic and pessimistic scenarios. The calculated cost per DALY was compared against gross domestic product (GDP; below 1-3 times national GDP) to consider as a cost-effective intervention. The existing national food basket supplies a total of 28·2 µg of Se for adults and 11·3 µg of Se for children, where the risk of inadequate dietary Se reaches 99·1 %-100 %. Cereals account for 61 % of the dietary Se supply. Human Se deficiency contributes to 0·164 million DALYs among children and women. Hence, 52 %, 43 %, and 5 % of the DALYs lost are attributed to anaemia, goiter, and cognitive dysfunction, respectively. Application of Se fertilisers to soils could avert an estimated 21·2-67·1 %, 26·6-67·5 % and 19·9-66·1 % of DALY via maize, teff and wheat at a cost of US$129·6-226·0, US$149·6-209·1 and US$99·3-181·6, respectively. Soil Se fertilisation of cereals could therefore be a cost-effective strategy to help alleviate Se deficiency in Ethiopia, with precedents in Finland.

Nanomaterial-Based Biofortification: Potential Benefits and Impacts of Crops

Nanomaterials (NMs) have shown relevant impacts in crop protection, improvement of yields, and minimizing collateral side effects of fertilizer and pesticides in vegetable and fruit production. The application of NMs to improve biofortification has gained much attention in the last five years, offering a hopeful and optimistic outlook. Thus, we propose comprehensively revising the scientific literature about the use of NMs in the agronomic biofortification of crops and analyzing the beneficial impact of the use of NMs. The results indicated that different species of plants were biofortified with essential elements and macronutrients after the applications of Zn, Fe, Se, nanocomposites, and metalloid NPs. In addition, the physiological performances, antioxidant compounds, and yields were improved with NMs. Using nanofertilizers for the biofortification of crops can be considered a promising method to deliver micronutrients for plants with beneficial impacts on human health, the environment, and agriculture.

Molecular mechanisms of growth promotion and selenium enrichment in tomato plants by novel selenium-doped carbon quantum dots

Selenium (Se)-doped nanoparticles as novel Se fertilizers have a promising potential in the agricultural application. Here, the effects of two novel Se-doped carbon quantum dots (Se-CQDs1 and Se-CQDs2, prepared using co-cracking and adsorption-reduction methods, respectively) on the growth and Se enrichment of tomato plants were studied, where the promoting molecular mechanisms were explored in terms of the related genes expression and soil microbial composition. The results indicated that the soil application of 2.5 mg kg-1 Se-CQDs1 more significantly increased the root growth, plant biomass, and fruit yield than that of Se-CQDs2 and Na2SeO3 treatments (control). Specifically, Se-CQDs1 treatment was more effective to up-regulate the expressions of aquaporin gene (i.e., PIP) and growth hormone synthesis gene (i.e., NIT) than Se-CQDs1 and Na2SeO3 treatments. The expressions of Se methyltransferase gene (smt) and methionine methyltransferase gene (mmt) induced by Se-CQDs1 were 1.45 and 1.18 times higher than that by Se-CQDs2 as well as 1.82 and 2.17 times higher than that by Na2SeO3. Also, Se-CQDs1 more greatly increased the diversity and relative abundance of soil bacterial communities, especially the Actinobacteria phylum, which was beneficial to increase plant growth-promoting substances. These outstanding promoting effects of Se-CQDs1 were mainly ascribed to its higher hydrophilicity and content of the stable doped-Se. The overall results demonstrated that Se-CQDs would be a promising candidate for nano-fertilizer to increase crop growth and development (e.g., tomato plants), where the synthesis modes of Se-CQDs play a critical role in regulating the utilization efficiency of Se.

Identification and Functional Characterization of a Surfactant-like Protein Region in Flagellin FliC for Stabilizing Selenium Nanoparticles and Enhancing Bioavailability

Biogenic selenium nanoparticles (SeNPs) are the most favorable Se form for nutritional supplementation due to their high stability, low toxicity, and high activity. However, the interaction between the surface-binding proteins and their stable biogenic SeNPs, as well as their impact on the stability and bioavailability of SeNPs, remains to be understood. In vitro stabilization experiments revealed an amino acid segment (F(235-386)) in Rahnella aquatilis' flagellin FliC, with surfactant-like properties, stabilizing SeNPs under harsh conditions. FliC and F(235-386) were employed as stabilizers to synthesize SeNPs (FliC@SeNPs and F(235-386)@SeNPs), and surface chemistry analysis revealed coordination reactions between the proteins and Se atoms on the surface of SeNPs. Both FliC and F(235-386) enhanced SeNPs uptake in wheat seedlings but reduced it in bacteria and yeast. This study highlights FliC's core function in stabilizing SeNPs and enhancing their bioavailability, paving the way for agricultural and nutritional applications.

Improved titer and stability of selenium nanoparticles produced by engineered Saccharomyces cerevisiae

Selenium nanoparticles (SeNPs) have gained significant attention in the fields of medicine and healthcare products due to their various biological activities and low toxicity. In this study, we focused on genetically modifying the Saccharomyces cerevisiae strain YW16 (CICC 1406), which has the ability to efficiently reduce sodium selenite and produce red SeNPs. By overexpressing genes involved in glutathione production, we successfully increased the glutathione titer of the modified strain YJ003 from 41.0 mg/L to 212.0 mg/L. Moreover, we improved the conversion rate of 2.0 g/L sodium selenite from 49.3% to 59.6%. Furthermore, we identified three surface proteins of SeNPs, and found that overexpression of Act1, one of the identified proteins, led to increased stability of SeNPs across different acid-base and temperature conditions. Through a 135-h feed fermentation process using 5.0 g/L sodium selenite, we achieved an impressive conversion rate of 88.7% for sodium selenite, and each gram of SeNPs contained 195.7 mg of selenium. Overall, our findings present an efficient method for yeast to synthesize SeNPs with high stability. These SeNPs hold great potential for applications in nanomedicine or as nutritional supplements to address selenium deficiency.

Population status of selenium in Colombia and associated factors: a cross-sectional study

OBJECTIVES

This study aims to investigate the population status of selenium in Colombia and other associated factors.

METHODS

Cross-sectional study, in population of urban or rural origin (n=412). Main outcome measures were: median serum selenium, thyrotropin, the prevalence of and positivity of anti-thyroid peroxidase, anti-thyroglobulin, and anti-TSH receptor.

RESULTS

This study found that 96.6% of the subjects had normal selenium levels, and no significant associations were found between the population median of selenium and overweight/obesity, sociodemographic variables, age, goiter, and thyroid antibody positivity.

CONCLUSIONS

In Colombia, the population status of selenium is normal, and the geological characteristics may contribute to the state of selenium in this population. However, additional studies are required to evaluate the content of selenium in plants and other foods.

Time-Resolved Examination of Fungal Selenium Redox Transformations

Selenium (Se) is both a micronutrient required for most life and an element of environmental concern due to its toxicity at high concentrations, and both bioavailability and toxicity are largely influenced by the Se oxidation state. Environmentally relevant fungi have been shown to aerobically reduce Se(IV) and Se(VI), the generally more toxic and bioavailable Se forms. The goal of this study was to shed light on fungal Se(IV) reduction pathways and biotransformation products over time and fungal growth stages. Two Ascomycete fungi were grown with moderate (0.1 mM) and high (0.5 mM) Se(IV) concentrations in batch culture over 1 month. Fungal growth was measured throughout the experiments, and aqueous and biomass-associated Se was quantified and speciated using analytical geochemistry, transmission electron microscopy (TEM), and synchrotron-based X-ray absorption spectroscopy (XAS) approaches. The results show that Se transformation products were largely Se(0) nanoparticles, with a smaller proportion of volatile, methylated Se compounds and Se-containing amino acids. Interestingly, the relative proportions of these products were consistent throughout all fungal growth stages, and the products appeared stable over time even as growth and Se(IV) concentration declined. This time-series experiment showing different biotransformation products throughout the different growth phases suggests that multiple mechanisms are responsible for Se detoxification, but some of these mechanisms might be independent of Se presence and serve other cellular functions. Knowing and predicting fungal Se transformation products has important implications for environmental and biological health as well as for biotechnology applications such as bioremediation, nanobiosensors, and chemotherapeutic agents.

Effect of selenium nanoparticles on biological and morphofunctional parameters of barley seeds (Hordéum vulgáre L.)

The purpose of this work was to study the effect of selenium nanoparticles (Se NPs) on the biological and morphofunctional parameters of barley seeds (Hordéum vulgáre L.) We used seeds of Hordéum vulgáre L. with reduced morphofunctional characteristics. For the experiment, Se NPs were synthesized and stabilized with didecyldimethylammonium chloride. It was found that Se NPs have a spherical shape and a diameter of about 50 nm. According to dynamic light scattering data, the average hydrodynamic radius of the particles was 28 ± 8 nm. It is observed that the nanoparticles have a positive ζ-potential (+ 27.3 mV). For the experiment, we treated Hordéum vulgáre L. seeds with Se NPs (1, 5, 10 and 20 mg/L). The experiment showed that treatment of Hordéum vulgáre L. seeds with Se NPs has the best effect on the length of roots and sprout at concentration of 5 mg/L and on the number and thickness of roots at 10 mg/L. Germinability and germination energy of Hordéum vulgáre L. seeds were higher in group treated with 5 mg/L Se NPs. Analysis of macrophotographs of samples, histological sections of roots and 3D visualization of seeds by microcomputing tomography confirmed the best effect at 5 mg/L Se NPs. Moreover, no local destructions were detected at concentrations > 5 mg/L, which is most likely due to the inhibition of regulatory and catalytic processes in the germinating seeds. the treatment of Hordéum vulgáre L. seeds with > 5 mg/L Se NPs caused significant stress, coupled with intensive formation of reactive oxygen species, leading to a reorientation of root system growth towards thickening. Based on the results obtained, it was concluded that Se NPs at concentrations > 5 mg/L had a toxic effect. The treatment of barley seeds with 5% Se NPs showed maximum efficiency in the experiment, which allows us to further consider Se NPs as a stimulator for the growth and development of crop seeds under stress and reduced morphofunctional characteristics.

Selenium as a predictor of metabolic syndrome in middle age women

BACKGROUND

Selenium plays an important role in metabolic homeostasis. It has been suggested that it may also affect the expression and activity of PPAR-γ. The aim of study was to analyze the relationships between these variables in the context of the health of women, for whom the risk of MetS increases with age.

MATERIAL AND METHODS

The study involved 390 women in middle age. The stages of study: a survey-based part; anthropometric measurements; analysis of biological material (blood) in terms of glycemia, triglyceride, HDL, and selenium levels, as well as genetic analysis of the PPAR-γ polymorphisms.

RESULTS

It was found that selenium may moderate the effect of the G allele of the PPAR-γ gene on the occurrence of elevated waist circumference (OR=1.030, 95%CI 1.005-1.057, p=0.020); and the effect of the C (OR=1.077, 95%CI 1.009-1.149, p=0.026) and the G alleles (OR=1.052, 95%CI 1.025-1.080, p<0.000) on the odds of elevated blood pressure. Women in whom HDL levels were not significantly reduced, had higher selenium levels (p=0.007).

CONCLUSIONS

1. The effect of selenium on MetS and its components has not been demonstrated. 2. The effect of individual alleles of the PPAR-γ gene on MetS and its components was not demonstrated. 3. The concentration of selenium may affect waist circumference in carriers of the G allele, and arterial hypertension in carriers of the C and G alleles by affecting the expression of PPAR-γ. 4. Higher selenium concentrations increased the odds of higher HDL levels in the group of subjects meeting the MetS criteria.

The Integral Boosting Effect of Selenium on the Secondary Metabolism of Higher Plants

Selenium is a micronutrient with a wide range of functions in animals, including humans, and in microorganisms such as microalgae. However, its role in plant metabolism remains ambiguous. Recent studies of Se supplementation showed that not only does it increase the content of the element itself, but also affects the accumulation of secondary metabolites in plants. The purpose of this review is to analyze and summarize the available data on the place of selenium in the secondary metabolism of plants and its effect on the accumulation of some plant metabolites (S- and N-containing secondary metabolites, terpenes, and phenolic compounds). In addition, possible molecular mechanisms and metabolic pathways underlying these effects are discussed. It should be noted that available data on the effect of Se on the accumulation of secondary metabolites are inconsistent and contradictory. According to some studies, selenium has a positive effect on the accumulation of certain metabolites, while other similar studies show a negative effect or no effect at all. The following aspects were identified as possible ways of regulating plant secondary metabolism by Se-supplementation: changes occurring in primary S/N metabolism, hormonal regulation, redox metabolism, as well as at the transcriptomic level of secondary metabolite biosynthesis. In all likelihood, the confusion in the results can be explained by other, more complex regulatory mechanisms in which selenium is involved and which affect the production of metabolites. Further study on the involvement of various forms of selenium in metabolic and signaling pathways is crucial for a deeper understanding of its role in growth, development, and health of plants, as well as the regulatory mechanisms behind them.

Evaluation of foliar application of selenium and flowering stages on selected properties of Iranian Borage as a medicinal plant

Many of the active constituents of drug or medicines were originally derived from medicinal plants. Iranian Borage are still being used in regular basis. Selenium (Se) is an essential mineral nutrient for animal and human growth. The aim of this research was to determine the effect of (2, 4, 8 and 16 mg L⁻¹) of as sodium selenate (Na₂SeO₄) and as sodium selenite (Na₂SeO₃) on some important properties of Iranian Borage in factorial based on Randomized Complete Block Design via four steps: 2 true leaves stage, ten leaves, 2 weeks and 1 week before flowering. The traits were evaluated during flowering period. Results showed that the highest shoot fresh and dry weight and shoot length, total alkaloid, essential oil percentage were obtained by 4 mg L⁻¹ sodium selenate at the end of flowering. In addition, 4 mg L⁻¹ sodium selenate concentration significantly improved flower yield (diameter, number, weight). The plants were treated with 8 mg L⁻¹ sodium selenate, the higher total phenols and flavonoids, antioxidant activity, soluble sugars, root and fresh weight was seen at end of flowering. When the plants were sprayed with 4 mg L⁻¹ sodium selenite higher total chlorophyll was observed at full of flowering. 16 mg L⁻¹ sodium selenite released the maximum Se acclimation in the petals. 20 composites were discovered containing ɑ-Pinene (23.61%) with sodium selenate in 4 mg L⁻¹. Generally, selenium sources significantly improved morpho-physiological and phytochemical.

Metabolism and Anticancer Mechanisms of Selocompounds: Comprehensive Review

Selenium (Se) is an essential micronutrient with several functions in cellular and molecular anticancer processes. There is evidence that Se depending on its chemical form and the dosage use could act as a modulator in some anticancer mechanisms. However, the metabolism of organic and inorganic forms of dietary selenium converges on the main pathways. Different selenocompounds have been reported to have crucial roles as chemopreventive agents, such as antioxidant activity, activation of apoptotic pathways, selective cytotoxicity, antiangiogenic effect, and cell cycle modulation. Nowadays, great interest has arisen to find therapies that could enhance the antitumor effects of different Se sources. Herein, different studies are reported related to the effects of combinatorial therapies, where Se is used in combination with proteins, polysaccharides, chemotherapeutic agents or as nanoparticles. Another important factor is the presence of single nucleotide polymorphisms in genes related to Se metabolism or selenoprotein synthesis which could prevent cancer. These studies and mechanisms show promising results in cancer therapies. This review aims to compile studies that have demonstrated the anticancer effects of Se at molecular levels and its potential to be used as chemopreventive and in cancer treatment.

Blood Trace Element Status in Camels: A Review

Trace minerals play an important role in animal health and productivity. They are involved also in many physiological activities, and their deficiency causes a variety of pathological problems and metabolic defects, reducing consequently the animal productivity. The demand for animal products in semi-arid areas is rapidly increasing, and the supply is still below the required level, partially due to low animal productivity. Camels (Camelus dromedarius and Camelus bactrianus) are considered one of the main sources of healthy, high-quality meat and milk for human consumption within most of the countries in the semi-arid regions. Despite their efficient adaptation to their environment, camels can suffer from the growth retardation of newborns, low feed efficiency, anemia, poor fertility, poor reproduction and many other metabolic disorders. It is well known that trace mineral deficiencies and trace mineral toxicities can influence camels' production and reproductive efficiency, as well as many aspects of their growth and metabolism. Evaluating the trace minerals status of camels and their variability is an obvious step toward improving camels' productivity and health. Thus, the present article reviews the data regarding the status of trace minerals (copper, zinc, iron, selenium, manganese, cobalt, iodine, fluorine, molybdenum, sulfur, bromide and nickel) in camel blood and their physiological variability, with a focus on their deficiency and toxicity effects.

Evaluation of collision/reaction gases in single-particle ICP-MS for sizing selenium nanoparticles and assessment of their antibacterial activity

Selenium nanoparticles (SeNPs) have recently attracted attention because they combine the benefits of Se and lower toxicity compared to other chemical forms of this element. In this study, SeNPs were synthesized by a green method using ascorbic acid as the reducing agent and polyvinyl alcohol as stabilizer. The nanoparticles were widely characterized. To determine the total concentration of Se by ICP-MS, several isotopes and the use of He as collision gas were evaluated, which was effective in minimizing interferences. A method for sizing SeNPs by single particle ICP-MS (SP-ICP-MS) was developed. For this purpose, He and H₂were evaluated as collision/reaction gases, and the second one showed promising results, providing an average diameter of 48 nm for the SeNPs. These results agree with those obtained by TEM (50.1 nm). Therefore, the SP-ICP-MS can be implemented for characterizing SeNPs in terms of size and size distribution, being an important analytical tool for Se and other widely studied nanoparticles (e.g. Ag, Au, Ce, Cu, Fe, Zn). Finally, the antibacterial activity of SeNPs was assessed. The SeNPs showed bacteriostatic activity against three strains of Gram-positive bacteria and were particularly efficient in inhibiting the growthE. faecaliseven at very low concentrations (MIC < 1.4 mg l^-1). In addition, a bactericidal activity of SeNPs againstS. aureuswas observed. These nanoparticles may have potential application in pharmaceutical industry, biomedicine and agriculture.

Selenium intake is not associated with the metabolic syndrome in Brazilian adolescents: an analysis of the Study of Cardiovascular Risk Factors in Adolescents

Se reduces cellular inflammation and lipid peroxides; therefore, its association with CVD and the metabolic syndrome (MetS) has been studied. We aimed to investigate the association between Se intake and the MetS and its parameters (high waist circumference, hyperglycaemia, high blood pressure, high TAG and low HDL-cholesterol) in Brazilian adolescents between 12 and 17 years old. This research is part of the Study of Cardiovascular Risks in Adolescents (ERICA), a Brazilian nationwide school-based study with regional and national relevance. We assessed: (1) socio-demographic data (sex, age, type of school and maternal education) using a self-administered questionnaire; (2) dietary intake using a 24-h recall applied for the whole sample and a second one applied to a subsample to allow within-person variability adjustment; (3) anthropometric data (weight, height, waist circumference) and blood pressure using standardised procedures; and (4) biochemical analyses (fasting glucose, TAG and HDL-cholesterol). Logistic regression was applied, basing the analysis on a theoretical model. Median Se intake was 98·3 µg/d. Hypertension and hyperglycaemia were more prevalent among boys, while a high waist circumference was more frequent in girls, and low HDL-cholesterol levels were higher among private school students. The prevalence of the MetS was 2·6 %. No association between the MetS and its parameters and Se intake was found. This lack of association could be due to an adequate Se intake in the studied population.

Detoxification difference of cadmium between the application of selenate and selenite in native cadmium-contaminated soil

Cadmium (Cd) has strong mobility and could cause toxicity to plants, and selenium (Se) can effectively detoxify Cd stress. However, differences in the detoxification effects of different species and dosages of exogenous Se on Cd and its mechanism are still unclear. In this study, a pot experiment was conducted to determine the effects of different rates of selenite and selenate application on radish growth, the uptake and translocation of Cd, and the fractions of Cd transformation in native Cd-contaminated soil. Results indicated that the decrease in radish biomass in selenate treatment was significantly greater than that in selenite treatment at a high Se application rate (2.5 mg·kg^-1) (p < 0.05). In contrast to selenite treatments, the application of selenate significantly increased the translocation of Cd from radish roots to shoots (p < 0.05). Cadmium concentration and its bioaccumulation factor in radish decreased gradually with increasing selenite application rates, while these values decreased at low Se rate (1 mg·kg^-1) and increased at high Se rate for selenate treatment. Different Se application rates resulted in Cd fractions distributions to change in soil. Therefore, the application of selenite treatment had a greater detoxification effect on Cd in soil than that in selenate treatment, and the double toxic effect was observed between Se and Cd in high selenate treatment (2.5 mg·kg^-1). Combined with human health risk asseeement, the application of 2.5 mg·kg^-1 selenite could be a good approach for detoxification in native Cd-contaminated soil used in this study.

Survival of Embryos and Fry of Sea Trout (Salmo trutta m. trutta) Growing from Eggs Exposed to Different Concentrations of Selenium during Egg Swelling

Adequate selenium (Se) availability enhances the health and growth of organisms, but overdose of it can be harmful and pathogenic. The study's objective was to analyse the impact of short-term exposure of sea trout fertilised eggs to inorganic selenium (SeO₂) at concentrations from 0 to 32 mg Se L^-1 to find the optimal and toxic dose of Se on early fish development. Se accumulated in the body, embryos' survival rate, and growth in the first four months of life was examined. Swelling of fertilised eggs in water supplemented with Se at a concentration from 0.5 to 8 mg Se L^-1 was associated with a slightly positive impact on the hatching rate. At higher Se concentration, a harmful effect on the survival of the embryo was observed. The survival of fry was similar in all groups, while the fry length and weight correlated positively with Se concentration in its body. Immersion of fertilised eggs in water enriched with Se during egg swelling can constitute a method to supplement the element to non-feeding stages of fish. In selenium-poor areas, this innovative method can be implemented in aquaculture to improve breeding outcomes. Se concentration should be adjusted to the chemical compound, fish species, and Se's content in the yolk.

Selenium alleviates arsenic induced stress by modulating growth, oxidative stress, antioxidant defense and thiol metabolism in rice seedlings

This study aims to investigate the potentiality of selenium in modulating arsenic stress in rice seedlings. Arsenate accumulation along with its transformation to arsenite was enhanced in arsenate exposed seedlings. Arsenite induced oxidative stress and severely affected the growth of the seedlings. Arsenate exposure caused an elevation in ascorbate and glutathione levels along with the activities of their metabolizing enzymes viz., ascorbate peroxidase, glutathione reductase, glutathione-S-transferase, and glutathione peroxidase. Phytochelatins content was increased under arsenic stress to subdue the toxic effects in the test seedlings. Co-application of arsenate and selenate in rice seedlings manifested pronounced alteration of oxidative stress, antioxidant defense, and thiol metabolism as compared to arsenate treatment only. ANOVA analysis (Tukey's HSD test) demonstrated the relevance of using selenate along with arsenate to maintain the normal growth and development of rice seedlings. Thus, exogenous supplementation of selenium will be a beneficial approach to cultivate rice seedlings in arsenic polluted soil.

Selenium speciation and bioavailability from mine discharge to the environment: a field study in Northern Quebec, Canada

The speciation, behaviour, and bioavailability of released selenium (Se) from mine effluent discharge to sediments and plants were assessed. Discharged mine effluent containing 65±0.9 μg/L of total Se subsequently contaminated the exposed sediment with an average total Se concentration of 321 mg/kg as well as exposed Typha latifolia plants where 534 and 92 mg/kg were found in roots and leaves, respectively. The strategy of T. latifolia in Se phytoremediation consisted of a phytostabilization and accumulation of Se predominantly in roots. Se plant root uptake was promoted by synergistic effects of Cu, Pb, Zn, and Cd while Co, Fe, Mn, Ni, Na, K, and Mg had antagonistic effects. Se plant uptake was also governed by sediment characteristics mainly pH, total Se, and iron concentration. Se speciation results demonstrated that the most accumulated Se species by T. latifolia roots were selenite and selenomethionine with average concentrations of 2.68 and 2.04 mg/kg respectively while other Se species were the most translocated (average translocation factor of 1.89). Se speciation in roots was positively correlated with sediment pH, organic matter, electrical conductivity, and iron concentration. This study confirms deploying corrective measures for mine effluent treatment before discharge in a sediment-plant environment to protect living organisms from toxic effects. T. latifolia is recommended as a Se-hyperaccumulator to be used for mine soil phytoremediation in cold regions in Canada.

Selenium yeast promoted the Se accumulation, nutrient quality and antioxidant system of cabbage (Brassica oleracea var. capitata L.)

The application of Se yeast as a Se source to cultivate Se-rich cabbage has a significant effect on cabbage growth and quality indices. Results showed that total plant weight, head weight, and head size in cabbage were notably increased by 48.4%, 88.3%, and 25.4% under 16 mg/kg Se yeast treatment, respectively. Compare with the control, a high proportion of 3874% of Se accumulation in cabbage head was also detected in 16 mg/kg Se yeast treatment. Selenocystine (SeCys₂) and Methyl-selenocysteine (MeSeCys) were the main Se speciations in the cabbage head. Application of 8 mg/kg Se yeast improved cabbage quality and antioxidant system indices, including free amino acid, soluble sugar, ascorbic acid, phenolic acid, glucosinolates, and SOD activity, which had 81.6%, 46.5%, 34.9%, 12.3%, 44.8%, 25.2% higher than that of the control, respectively. In summary, considering 8 mg/kg Se yeast as the appropriate level of Se enrichment during cabbage cultivation. These findings enhanced our understanding of the effects of Se yeast on the growth and quality of cabbage and provided new insights into Se-enrichment vegetable cultivation.

Nutritional approach for increasing public health during pandemic of COVID-19: A comprehensive review of antiviral nutrients and nutraceuticals

Background: The novel coronavirus (COVID-19) is considered as the most life-threatening pandemic disease during the last decade. The individual nutritional status, though usually ignored in the management of COVID-19, plays a critical role in the immune function and pathogenesis of infection. Accordingly, the present review article aimed to report the effects of nutrients and nutraceuticals on respiratory viral infections including COVID-19, with a focus on their mechanisms of action. Methods: Studies were identified via systematic searches of the databases including PubMed/ MEDLINE, ScienceDirect, Scopus, and Google Scholar from 2000 until April 2020, using keywords. All relevant clinical and experimental studies published in English were included. Results: Protein-energy malnutrition (PEM) is common in severe respiratory infections and should be considered in the management of COVID-19 patients. On the other hand, obesity can be accompanied by decreasing the host immunity. Therefore, increasing physical activity at home and a slight caloric restriction with adequate intake of micronutrients and nutraceuticals are simple aids to boost host immunity and decrease the clinical manifestations of COVID-19. Conclusion: The most important nutrients which can be considered for COVID-19 management are vitamin D, vitamin C, vitamin A, folate, zinc, and probiotics. Their adequacy should be provided through dietary intake or appropriate supplementation. Moreover, adequate intake of some other dietary agents including vitamin E, magnesium, selenium, alpha linolenic acid and phytochemicals are required to maintain the host immunity.

Profiling of selenium and other trace elements in breads from rice and maize cultivated in a seleniferous area of Punjab (India)

The objective of the study was to assess selenium and other elements levels in Indian Roti bread from Se-rich maize and rice using inductively coupled plasma mass-spectrometry. Se levels in Roti bread from Se-rich maize and rice exceeded those in the control samples by a factor of more than 594 and 156, respectively. Using Se-enriched maize increased bread Co, Cr, Mn, Mo, and Zn content, whereas Fe and I levels were reduced. In Se-rich rice-based bread a decrease in Co, Cr, Cu, Fe, I, Mo, and Zn contents was observed. Daily consumption of Se-rich maize and rice bread (100 g) could account for 5.665% and 4.309% from recommended dietary allowance, also exceeding the upper tolerable levels by a factor of 7.8 and 5.9, respectively. Therefore, Roti bread from both Se-rich maize and rice may be considered as an additional source of selenium. At the same time, regular intake of Se-rich grains and its products including breads may cause adverse health effects even after a few days and should be regularly monitored in order to prevent Se overload and toxicity.

Iodine Biofortification of Apples and Pears in an Orchard Using Foliar Sprays of Different Composition

Many people across the world suffer from iodine (I) deficiency and related diseases. The I content in plant-based foods is particularly low, but can be enhanced by agronomic biofortification. Therefore, in this study two field experiments were conducted under orchard conditions to assess the potential of I biofortification of apples and pears by foliar fertilization. Fruit trees were sprayed at various times during the growing season with solutions containing I in different concentrations and forms. In addition, tests were carried out to establish whether the effect of I sprays can be improved by co-application of potassium nitrate (KNO3) and sodium selenate (Na2SeO4). Iodine accumulation in apple and pear fruits was dose-dependent, with a stronger response to potassium iodide (KI) than potassium iodate (KIO3). In freshly harvested apple and pear fruits, 51% and 75% of the biofortified iodine was localized in the fruit peel, respectively. The remaining I was translocated into the fruit flesh, with a maximum of 3% reaching the core. Washing apples and pears with running deionized water reduced their I content by 14%. To achieve the targeted accumulation level of 50-100 μg I per 100 g fresh mass in washed and unpeeled fruits, foliar fertilization of 1.5 kg I per hectare and meter canopy height was required when KIO3 was applied. The addition of KNO3 and Na2SeO4 to I-containing spray solutions did not affect the I content in fruits. However, the application of KNO3 increased the total soluble solids content of the fruits by up to 1.0 °Brix compared to the control, and Na2SeO4 in the spray solution increased the fruit selenium (Se) content. Iodine sprays caused leaf necrosis, but without affecting the development and marketing quality of the fruits. Even after three months of cold storage, no adverse effects of I fertilization on general fruit characteristics were observed, however, I content of apples decreased by 20%.

Selenium Deficiency-Induced Pancreatic Pathology Is Associated with Oxidative Stress and Energy Metabolism Disequilibrium

Selenium (Se) is an essential micronutrient that plays a crucial role in development and physiological processes. The present study aimed to investigate the effects of Se deficiency on pancreatic pathology and the potential mechanism in pigs. Twenty-four castrated male Yorkshire pigs were divided into two groups and fed a Se-deficient diet (0.007 mg Se/kg) or a Se-adequate diet (0.3 mg Se/kg) for 16 weeks. The serum concentrations of insulin and glucagon, Se concentration, histologic characteristics, apoptotic status, antioxidant activity, free radical content, and major metabolite concentrations were analyzed. The results showed that Se deficiency reduced the concentrations of insulin and glucagon in the serum and of Se in pancreas, decreased the number of islets and cells in the local islets, and induced pancreatic apoptosis. Se deficiency caused a redox imbalance, which led to an increase in the content of free radicals and decreased the activity of antioxidant enzymes. Of 147 targeted metabolites judged to be present in pancreas, only hypotaurine and D-glucuronic acid had differential concentrations with the false discovery rate < 0.05. Pathway analysis using metabolites with differential expression (unadjusted P < 0.05, fold change > 1.4 or < 0.67) found that 8 glycolytic metabolites were significantly increased by Se-deficient, whereas most of the tricarboxylic acid cycle and pentose phosphate pathway metabolites were not significantly changed. Our studies indicated that Se deficiency-induced pancreatic pathology was associated with oxidative stress and enhanced activity of glycolysis, which may provide gaining insight into the actions of Se as a diabetogenic factor.

Distribution characteristics and main influencing factors of selenium in surface soil of natural selenium-rich area: a case study in Langao County, China

In order to study the distribution of selenium in surface soil and its main influencing factor, we collected 360 surface soil samples and four groups of soil profiles with 210 corresponding parent rock samples in Langao County, Shaanxi Province (a typical high-selenium area of Daba Mountain). Samples were analyzed for trace elements by using ICP-MS, ICP-OES and HG-AFS. The results show the following. (1) selenium content in surface soils of Langao County varies greatly (0.03-16.96 mg/kg). The mean selenium content in surface soils of Langao County is 0.99 mg/kg, higher than the global (0.4 mg/kg) and China (0.29 mg/kg) soil average, and 3.4 times the mean of soil selenium in China. (2) Selenium content of bedrock in Langao County also varies greatly (0.01-56.22 mg/kg), with an average selenium content of 2.02 mg/kg, which is 40 times higher than the upper crust (0.05 mg/kg). (3) Selenium content in the strata of the Late Precambrian-Early Paleozoic and its variation is an important factor affecting the spatial variation of soil selenium content. The black rock series (carbonaceous slate and silicon-bearing carbonaceous slate) of the Upper Ediacaran-Cambrian on the north side has the highest mean selenium content (> 7.92 mg/kg), and the selenium content of the surface soil in the distribution area can reach up to 16.96 mg/kg. The Middle Cambrian, Upper Cambrian, Ordovician and Silurian (limestone and marl) in the south has the lowest mean selenium content (< 2 mg/kg), and the selenium content of surface soil in the distribution area is lower than 0.8 mg/kg mostly. (4) Soil samples at different depths in the same soil profile have similar composition of rare earth elements (REE), and bedrock and corresponding topsoil has similar composition of REE. This study indicates the selenium content in the topsoil varies greatly, even in high-selenium area. And the difference of selenium distribution is closely related to the original selenium content of the bedrock.

Quantification and Tissue Localization of Selenium in Rice (Oryza sativa L., Poaceae) Grains: A Perspective of Agronomic Biofortification

In worldwide production, rice is the second-most-grown crop. It is considered a staple food for many populations and, if naturally enriched in Se, has a huge potential to reduce nutrient deficiencies in foodstuff for human consumption. This study aimed to develop an agronomic itinerary for Se biofortification of Oryza sativa L. (Poaceae) and assess potential physicochemical deviations. Trials were implemented in rice paddy field with known soil and water characteristics and two genotypes resulting from genetic breeding (OP1505 and OP1509) were selected for evaluation. Plants were sprayed at booting, anthesis and milky grain phases with two different foliar fertilizers (sodium selenate and sodium selenite) at different concentrations (25, 50, 75 and 100 g Se·ha⁻¹). After grain harvesting, the application of selenate showed 4.9–7.1 fold increases, whereas selenite increased 5.9–8.4-fold in OP1509 and OP1505, respectively. In brown grain, it was found that in the highest treatment selenate or selenite triggered much higher Se accumulation in OP1505 relatively to OP1509, and that no relevant variation was found with selenate or selenite spraying in each genotype. Total protein increased exponentially in OP1505 genotype when selenite was applied, and higher dosage of Se also increased grain weight and total protein content. It was concluded that, through agronomic biofortification, rice grain can be enriched with Se without impairing its quality, thus highlighting its value in general for the industry and consumers with special needs.

Se Status Prediction by Food Intake as Compared to Circulating Biomarkers in a West Algerian Population

Algeria is the largest country in Africa, located close to the Mediterranean coastal area, where nutrients consumption varies widely. Local data on selenium composition of foods are not available. We postulated a close correlation between selenium status predictions from food consumption analysis with a quantitative analysis of circulating biomarkers of selenium status. Population characteristics were recorded from 158 participants and dietary selenium intake was calculated by 24-h recall. The average total plasma selenium was 92.4 ± 18.5 µg/L and the mean of selenium intake was 62.7 µg/day. The selenoprotein P concentration was 5.5 ± 2.0 mg/L and glutathione peroxidase 3 activity was 247.3 ± 41.5 U/L. A direct comparison of the dietary-derived selenium status to the circulating selenium biomarkers showed no significant interrelation. Based on absolute intakes of meat, potato and eggs, a model was deduced that outperforms the intake composition-based prediction from all food components significantly (DeLong’s test, p = 0.029), yielding an area under the curve of 82%. Selenium status prediction from food intake remains a challenge. Imprecision of survey method or information on nutrient composition makes extrapolating selenium intake from food data providing incorrect insights into the nutritional status of a given population, and laboratory analyses are needed for reliable information.

Agronomic biofortification with selenium impacts storage proteins in grains of upland rice

BACKGROUND

Selenium (Se) is an essential element for humans and animals. Rice is one of the most commonly consumed cereals in the world, so the agronomic biofortification of cereals with Se may be a good strategy to increase the levels of daily intake of Se by the population. This study evaluated the agronomic biofortification of rice genotypes with Se and its effects on grain nutritional quality. Five rates of Se (0, 10, 25, 50, and 100 g ha ^-1 ) were applied as selenate via the soil to three rice genotypes under field conditions.

RESULTS

Selenium concentrations in the leaves and polished grains increased linearly in response to Se application rates. A highly significant correlation was observed between the Se rates and the Se concentration in the leaves and grains, indicating high translocation of Se. The application of Se also increased the concentration of albumin, globulin, prolamin, and glutelin in polished grains.

CONCLUSION

Biofortifying rice genotypes using 25 g Se ha ^-1 could increase the average daily Se intake from 4.64 to 66 μg day^-1 . Considering that the recommended daily intake of Se by adults is 55 μg day^-1 , this agronomic strategy could contribute to alleviating widespread Se malnutrition. © 2019 Society of Chemical Industry.

Selenium intake from tuna in Galicia (Spain): Health risk assessment and protective role against exposure to mercury and inorganic arsenic

This study aims to quantify the selenium contribution from tuna to the Spanish diet and evidence the Se protective role against mercury and inorganic arsenic toxicity. Selenium concentrations in tuna were determined by ICP-MS spectrometry (expressed as mg kg^-1), and the risk assessment was evaluated joined to Hg and iAs contrasting criteria of regulatory agencies with those that consider the Se protective role. Differences between Se average concentrations in fresh (1.24) and preserved (1.17) tuna were not statistically significant. In canned tuna species, Se presented higher mean levels in Thunnus albacares (1.28) than Thunnus alalunga (1.01) with statistically significant differences (p = 0.002), and among canned preparations a decreasing sequence was observed in different preparation-packaging media: oil (1.42) > natural (1.01) > pickled (0.92). Statistical study showed Hg-iAs as the only pair significantly correlated in all samples. The HI (sum of individual target hazard quotients -THQs-) on the consumption of tuna in Spain, due to exposure to Se, Hg and iAs, revealed the possibility of risk of adverse chronic effects in the six-year-old children group (1.09). According to the maximum allowable tuna consumption rate in meals/week (CR_mw) and the THQs obtained, tuna intake, especially in children, should be moderated. The health benefit values (HBV_Se) were positive in all samples, 14.53 and 15.65 in fresh and preserved tuna, respectively, which allows tuna to be considered safe. The benefit-risk value (BRV) evidenced the Se molar excess with respect to Hg that reached a surplus of 14.32% on Se AI in adults. Since iAs reduces the Se bioavailability, applying a new BRV criterion, the aforementioned percentage decreased to 13.49% of Se AI. In conclusion, tuna offers high levels of selenium to counteract adverse effects by the presence of Hg and iAs, and to provide consumers an important source of this essential element safely.

Selenium and Other Elements in Wheat (Triticum aestivum) and Wheat Bread from a Seleniferous Area

The objective of the present study was to assess the levels of Se, as well as other essential and toxic trace elements in wheat grains and traditional Roti-bread from whole-grain flour in a seleniferous area of Punjab (India) using inductively-coupled plasma mass-spectrometry. Wheat grain and bread selenium levels originating from seleniferous areas exceeded the control values by a factor of more than 488 and 179, respectively. Se-rich wheat was also characterized by significantly increased Cu and Mn levels. Se-rich bread also contained significantly higher levels of Cr, Cu, I, Mn, and V. The level of Li and Sr was reduced in both Se-enriched wheat and bread samples. Roti bread from Se-enriched wheat was also characterized by elevated Al, Cd, and Ni, as well as reduced As and Hg content as compared to the respective control values. Se intake with Se-rich bread was estimated as more than 13,600% of RDA. Daily intake of Mn with both Se-unfortified and Se-fortified bread was 133% and 190% of RDA. Therefore, Se-rich bread from wheat cultivated on a seleniferous area of Punjab (India) may be considered as a potent source of selenium, although Se status should be monitored throughout dietary intervention.

Se and I status in pregnant ewes from a pastoral system and the effect of supplementation with Se and I or only Se on wool quality of lambs

Australian Merino ewes and lambs producing fine fibre wool for export are raised in the north-west of Uruguay in pasture-based systems. We studied the status of selenium and iodine in pregnant Merino ewes (10 per treatment) grazing in natural pasture, in natural pasture and supplemented with Se (0.1 mg Se/kg dry matter intake) and I (1 mg I/kg dry matter intake), or in natural pasture and supplemented with Se alone (0.1 mg Se/kg dry matter intake), during the last 30 days of gestation. Further, we evaluated the performance and wool quality of their offspring. Content of Se and I in natural pasture, in the sera of pregnant ewes, and in the wool of their offspring and levels of thyroidal hormones—TSH, T4, and free T3 (FT3)—in the sera of pregnant ewes were determined. The performance of lambs and the commercial parameters of fine fibre wool produced were measured. Results showed normal Se levels in serum (0.12–0.15 mg/l) in the ewes grazing in natural pasture (0.07–0.09 mg/kg DM) during late pregnancy. The observed increase in Se content in the pasture at lambing (0.11–0.16 mg/kg DM) improved serum Se levels (0.216 mg/l); however, the serum levels were not affected by the supplementation.

I content in pasture showed adequate levels (0.50–0.60 mg/kg DM), which were reflected in the blood serum values 30 days prior to lambing (0.197–0.208 mg/l). However, at lambing, the I content in blood serum decreased (0.150 mg/l). Further, the supplementation did not modify the serum I levels (0.163–0.175 mg/l). An increase in FT3 levels in ewes at lambing could be associated with the increase in Se content in pasture and/or the adequate I content in pasture. No effect of supplementation was observed. Lambs showed good results regarding the quality of fine fibre wool and performance after supplementation with Se and I or Se alone and exhibited slightly improved Se and I content in wool. In conclusion, natural pasture provides adequate status in Se and I for the Merino ewes and their offspring without any additional beneficial effects of supplementation with Se and I or only Se.

Selenium Accumulation, Speciation and Localization in Brazil Nuts (Bertholletia excelsa H.B.K.)

More than a billion people worldwide may be selenium (Se) deficient, and supplementation with Se-rich Brazil nuts may be a good strategy to prevent deficiency. Since different forms of Se have different nutritional value, and Se is toxic at elevated levels, careful seed characterization is important. Variation in Se concentration and correlations of this element with other nutrients were found in two batches of commercially available nuts. Selenium tissue localization and speciation were further determined. Mean Se levels were between 28 and 49 mg kg⁻¹, with up to 8-fold seed-to-seed variation (n = 13) within batches. Brazil nut Se was mainly in organic form. While present throughout the seed, Se was most concentrated in a ring 1 to 2 mm below the surface. While healthy, Brazil nuts should be consumed in moderation. Consumption of one seed (5 g) from a high-Se area meets its recommended daily allowance; the recommended serving size of 30 g may exceed the allowable daily intake (400 μg) or even its toxicity threshold (1200 μg). Based on these findings, the recommended serving size may be re-evaluated, consumers should be warned not to exceed the serving size and the seed may be sold as part of mixed nuts, to avoid excess Se intake.

Estimated dietary intake of essential elements from four selected staple foods in Najran City, Saudi Arabia

The estimated dietary intake (EDI) of essential elements selenium (Se), zinc (Zn), manganese (Mn) and copper (Cu) has not been previously investigated for Najran city, Saudi Arabia. This type of information can be valuable for protecting public health. The aim of this study was to estimate the EDI of these elements. A food frequency questionnaire (FFQ) was completed by the study participants (n = 80) to obtain dietary intake of selected staple foods (rice, wheat, meat and chicken). The concentrations of Se, Zn, Mn and Cu in these staple foods were determined using inductively coupled plasma-mass spectrometry (ICP-MS). The ranges of concentrations (mg/kg, wet weight) were as follows: Se (0.07–0.24), Zn (3.91–20.89), Mn (0.63–14.69) and Cu (0.69–2.41). The calculated ranges of EDIs (mg/kg bw/day) for the essential elements were as follows: Se 9.55 × 10⁻⁵–5.75 × 10⁻⁴, Zn 1.33 × 10⁻²–5.83 × 10⁻², Mn 1.49 × 10⁻³–3.31 × 10⁻², Cu 1.65 × 10⁻³–5.42 × 10⁻³. The highest EDI for Cu and Mn came from wheat. In the case of Se and Zn, the foods that contributed the highest EDI were chicken and meat, respectively. The lowest EDIs were found for Se in wheat, Zn in rice and both Mn and Cu in chicken. The percentages (%) of provisional maximum tolerable daily intake (PMTDI) for Se, Zn, Mn and Cu were 13%, 11%, 14% and 3.4%, respectively when contributions from all the four classes of foods were combined. The percentage of the recommended daily allowance (RDA) derived from these foods were 80%, 20%, 17% and 5.6% for Se, Zn, Mn and Cu were, respectively. This raises the possibility of Cu deficiency in the Najran population. However, a total diet study and human biomonitoring study is needed in the future to fully assess if people in Najran city are at risk of deficiency or excessive exposure to trace elements.

The Role of the Status of Selected Micronutrients in Shaping the Immune Function

OBJECTIVE

This narrative review gives an overview on the essential role of adequate nutrition to an optimally functioning immune defence. Micronutrients act as regulators of the immune response, with the focus of this review on the immunomodulatory effects of the trace elements iron, zinc and selenium, and the vitamins A, D, E, C, B6 and B12 and folic acid.

RESULTS

Iron deficiency especially impairs the Th1 cell-borne cellular immunity. T lymphocytes are also most affected by a deficiency of zinc, needed for their maturation and the balance between the different T cell subpopulations and acting as a redox signal in the regulation of many enzymes. Selenium is also involved in redox reactions as the glutathione peroxidases and other redox enzymes are selenoproteins. Selenium status has shown special effects on cellular immunity and resistance to viral infections. Vitamin A in the form of retinoic acid induces a humoral Th2 cell response via antigen-presenting cells and is involved in maintaining intestinal immune defence and tolerance through its nuclear receptor RAR and via kinase signalling cascades. Immune tolerance is particularly promoted by vitamin D acting through dendritic cells to stimulate the differentiation of regulatory T cells. Vitamin E has antiinflammatory effects and stimulates naïve T cells especially in the elderly. Besides its antioxidative properties, vitamin C has effects on cell signalling and epigenetic regulation. The B vitamins are required for cytotoxic cellular immunity and modulate T cell responses.

CONCLUSION

A diverse diet and regular exposure to sunlight are the best sources for a balanced nutrient supply to maintain an optimal immune defence.

Effects of graded concentrations of supplemental selenium on selenium concentrations in tissues and prediction equations for estimating dietary selenium intake in pigs

The experiment was conducted to determine the effects of graded dietary selenium (Se) on organ weight and Se concentrations in tissues and to develop equations for estimating dietary Se intake in pigs. Sixteen barrows (initial body weight = 30.0 ± 2.6) were allotted to four dietary treatments including graded Se supplementations with 0, 1, 5, and 50 mg/kg of diet. The experimental diets fed to the pigs for 30 d, and then the pigs were euthanized, and the organs, muscle, and urine samples were collected. The hair and blood samples of pigs were collected on d 15 and 30. Equations were developed for predicting daily Se intake using the Se concentration in plasma, hair, liver, kidneys, muscle, or urine. For graded dietary Se concentrations, linear and quadratic effects on the final body weight, weight and relative weight of liver and kidneys were not observed. The Se concentration in plasma, hair, liver, kidneys, muscle, and urine were linearly and quadratically increased as dietary Se concentration increased (P < 0.001). The dietary Se concentration was positively correlated with the Se concentrations in the plasma, organs, muscle, and urine (r > 0.81, P < 0.001). The equations for estimating dietary Se intake using the Se concentration in the plasma, hair, or organ as an independent variable were significant (P < 0.05). In conclusion, the dietary Se concentration was well reflected in the Se concentration in the plasma, hair, liver, kidneys, and urine. The Se concentration in the plasma, hair, liver, and kidneys can be used as an independent variable for estimating the Se intake.

Dietary selenium intake based on the Chinese Food Pagoda: the influence of dietary patterns on selenium intake

Background

Selenium (Se) is essential for humans, with many critical roles in physiological and pathophysiological processes. Fish, eggs and meats are usually the rich food sources of Se. To improve the nutritional status of population, a new version of balanced dietary pattern in the form of the Chinese Food Pagoda (2016) was proclaimed. This study aimed to evaluate the contribution of this balanced dietary pattern to daily Se intake, and to assess Se intake status of Chinese residents under this Food Pagoda scenario.

Methods

Based on the food consumption recommended in the Food Pagoda, this study collected the data of Se contents in various food composites and estimated dietary Se intakes (EI_TDS) in 12 provinces from the 4th China Total Diet Study. The estimated Se intakes based on the Chinese Food Pagoda (EI_CHFP) in 12 provinces were calculated. EI_TDS and EI_CHFP in various food groups among different regions were compared.

Results

The average EI_CHFP in all regions, within the range of 66.23–145.20 μg/day, was greater than the China recommended nutrient intake (RNI) (60 μg/day). None of the highest EI_CHFP went beyond the tolerable upper intake level of Se (400 μg/day). Animal source foods should be the primary source of daily Se intake according to the EI_CHFP. The average EI_TDS in China (88 μg/day) was in line with its range of EI_CHFP (81.01–124.25 μg/day), but that in half of the regions failed to achieve their lowest EI_CHFP. Significant differences between EI_TDS and EI_CHFP were observed in cereal food, aquatic and dairy products (P < 0.05), among which Se intake from aquatic and dairy products presented seriously insufficient in almost all regions.

Conclusions

The ideal dietary pattern recommended in the Food Pagoda can meet the daily requirements of Chinese population for Se intake to maintain optimal health. From the perspective of the balanced diet and Se-rich sources, the consumption of aquatic products should be increased appropriately to improve the general Se intake level of Chinese population.