Pharmaconutrition revisited for critically ill patients with coronavirus disease 2019 (COVID-19): Does selenium have a place?

Micronutrient Status of Critically Ill Patients with COVID-19 Pneumonia

Micronutrient deficiencies can develop in critically ill patients, arising from factors such as decreased intake, increased losses, drug interactions, and hypermetabolism. These deficiencies may compromise important immune functions, with potential implications for patient outcomes. Alternatively, micronutrient blood levels may become low due to inflammation-driven redistribution rather than consumption. This explorative pilot study investigates blood micronutrient concentrations during the first three weeks of ICU stay in critically ill COVID-19 patients and evaluates the impact of additional micronutrient administration. Moreover, associations between inflammation, disease severity, and micronutrient status were explored. We measured weekly concentrations of vitamins A, B6, D, and E; iron; zinc; copper; selenium; and CRP as a marker of inflammation state and the SOFA score indicating disease severity in 20 critically ill COVID-19 patients during three weeks of ICU stay. Half of the patients received additional (intravenous) micronutrient administration. Data were analyzed with linear mixed models and Pearson's correlation coefficient. High deficiency rates of vitamins A, B6, and D; zinc; and selenium (50-100%) were found at ICU admission, along with low iron status. After three weeks, vitamins B6 and D deficiencies persisted, and iron status remained low. Plasma levels of vitamins A and E, zinc, and selenium improved. No significant differences in micronutrient levels were found between patient groups. Negative correlations were identified between the CRP level and levels of vitamins A and E, iron, transferrin, zinc, and selenium. SOFA scores negatively correlated with vitamin D and selenium levels. Our findings reveal high micronutrient deficiency rates at ICU admission. Additional micronutrient administration did not enhance levels or expedite their increase. Spontaneous increases in vitamins A and E, zinc, and selenium levels were associated with inflammation resolution, suggesting that observed low levels may be attributed, at least in part, to redistribution rather than true deficiencies.

Selenium in the Prevention of SARS-CoV-2 and Other Viruses

The rapid spread of new pathogens (SARS-CoV-2 virus) that negatively affect the human body has huge consequences for the global public health system and the development of the global economy. Appropriate implementation of new safety regulations will improve the functioning of the current model supervising the inhibition of the spread of COVID-19 disease. Compliance with all these standards will have a key impact on the health behavior of individual social groups. There have been demonstrably effective treatments that proved to be effective but were rapidly dismissed for unknown reasons, such as ivermectin and hydroxychloroquine. Various measures are used in the world to help inhibit its development. The properties of this element provide hope in preventing the development of the SARS-CoV-2 virus. The aim of this review is to synthesize the latest literature data and to present the effect of sodium selenite in reducing the incidence of COVID-19 disease.

Biogenic Selenium Nanoparticles in Biomedical Sciences: Properties, Current Trends, Novel Opportunities and Emerging Challenges in Theranostic Nanomedicine

Selenium is an important dietary supplement and an essential trace element incorporated into selenoproteins with growth-modulating properties and cytotoxic mechanisms of action. However, different compounds of selenium usually possess a narrow nutritional or therapeutic window with a low degree of absorption and delicate safety margins, depending on the dose and the chemical form in which they are provided to the organism. Hence, selenium nanoparticles (SeNPs) are emerging as a novel therapeutic and diagnostic platform with decreased toxicity and the capacity to enhance the biological properties of Se-based compounds. Consistent with the exciting possibilities offered by nanotechnology in the diagnosis, treatment, and prevention of diseases, SeNPs are useful tools in current biomedical research with exceptional benefits as potential therapeutics, with enhanced bioavailability, improved targeting, and effectiveness against oxidative stress and inflammation-mediated disorders. In view of the need for developing eco-friendly, inexpensive, simple, and high-throughput biomedical agents that can also ally with theranostic purposes and exhibit negligible side effects, biogenic SeNPs are receiving special attention. The present manuscript aims to be a reference in its kind by providing the readership with a thorough and comprehensive review that emphasizes the current, yet expanding, possibilities offered by biogenic SeNPs in the biomedical field and the promise they hold among selenium-derived products to, eventually, elicit future developments. First, the present review recalls the physiological importance of selenium as an oligo-element and introduces the unique biological, physicochemical, optoelectronic, and catalytic properties of Se nanomaterials. Then, it addresses the significance of nanosizing on pharmacological activity (pharmacokinetics and pharmacodynamics) and cellular interactions of SeNPs. Importantly, it discusses in detail the role of biosynthesized SeNPs as innovative theranostic agents for personalized nanomedicine-based therapies. Finally, this review explores the role of biogenic SeNPs in the ongoing context of the SARS-CoV-2 pandemic and presents key prospects in translational nanomedicine.

Nutritional management of individuals with obesity and COVID-19: ESPEN expert statements and practical guidance

The COVID-19 pandemics has created unprecedented challenges and threats to patients and healthcare systems worldwide. Acute respiratory complications that require intensive care unit (ICU) management are a major cause of morbidity and mortality in COVID-19 patients. Among other important risk factors for severe COVID-19 outcomes, obesity has emerged along with undernutrition-malnutrition as a strong predictor of disease risk and severity. Obesity-related excessive body fat may lead to respiratory, metabolic and immune derangements potentially favoring the onset of COVID-19 complications. In addition, patients with obesity may be at risk for loss of skeletal muscle mass, reflecting a state of hidden malnutrition with a strong negative health impact in all clinical settings. Also importantly, obesity is commonly associated with micronutrient deficiencies that directly influence immune function and infection risk. Finally, the pandemic-related lockdown, deleterious lifestyle changes and other numerous psychosocial consequences may worsen eating behaviors, sedentarity, body weight regulation, ultimately leading to further increments of obesity-associated metabolic complications with loss of skeletal muscle mass and higher non-communicable disease risk. Therefore, prevention, diagnosis and treatment of malnutrition and micronutrient deficiencies should be routinely included in the management of COVID-19 patients in the presence of obesity; lockdown-induced health risks should also be specifically monitored and prevented in this population. In the current document, the European Society for Clinical Nutrition and Metabolism (ESPEN) aims at providing clinical practice guidance for nutritional management of COVID-19 patients with obesity in various clinical settings.

Antioxidant, Anti-inflammatory, and Immunomodulatory Roles of Nonvitamin Antioxidants in Anti-SARS-CoV-2 Therapy

Viral pathologies encompass activation of pro-oxidative pathways and inflammatory burst. Alleviating overproduction of reactive oxygen species and cytokine storm in COVID-19 is essential to counteract the immunogenic damage in endothelium and alveolar membranes. Antioxidants alleviate oxidative stress, cytokine storm, hyperinflammation, and diminish the risk of organ failure. Direct antiviral roles imply: impact on viral spike protein, interference with the ACE2 receptor, inhibition of dipeptidyl peptidase 4, transmembrane protease serine 2 or furin, and impact on of helicase, papain-like protease, 3-chyomotrypsin like protease, and RNA-dependent RNA polymerase. Prooxidative environment favors conformational changes in the receptor binding domain, promoting the affinity of the spike protein for the host receptor. Viral pathologies imply a vicious cycle, oxidative stress promoting inflammatory responses, and vice versa. The same was noticed with respect to the relationship antioxidant impairment-viral replication. Timing, dosage, pro-oxidative activities, mutual influences, and interference with other antioxidants should be carefully regarded. Deficiency is linked to illness severity.

Hyperferritinemia, Low Circulating Iron and Elevated Hepcidin May Negatively Impact Outcome in COVID-19 Patients: A Pilot Study

Inflammation in COVID-19 produces intracellular iron overload with low circulating iron available for metabolic processes. The accumulated intracellular iron generates reactive species of oxygen and results in ferroptosis, a non-programmed cell death. Since no organ is spared, iron dysmetabolism increases the mortality and morbidity. Hepcidin and the mediator interleukin 6 are believed to play a role in the process. Our aim is to evaluate the predictive values of serologic iron and inflammatory parameters in COVID-19 critically ill patients. Hence, 24 patients were included. Hepcidin and interleukin 6, along with routine blood parameters, were determined and outcomes, such as death, multiple organ damage (MOD), anemia, and need for transfusions, were assessed. The results of this pilot study indicate that iron metabolism parameters individually, as well as models consisting of multiple laboratory and clinical variables, may predict the outcomes. Further larger studies are needed to validate the results of this pilot stud. However, this paper identifies a new direction for research.

Trace element homeostasis in the neurological system after SARS-CoV-2 infection: Insight into potential biochemical mechanisms

BACKGROUND

Several studies have suggested that COVID-19 is a systemic disease that can affect several organs, including the brain. In the brain, specifically, viral infection can cause dyshomeostasis of some trace elements that promote complex biochemical reactions in specialized neurological functions.

OBJECTIVE

Understand the neurovirulence of SARS-CoV-2 and the relationship between trace elements and neurological disorders after infection, and provide new insights on the drug development for the treatment of SARS-CoV-2 infections.

METHODS

The main databases were used to search studies published up September 2021, focusing on the role of trace elements during viral infection and on the correct functioning of the brain.

RESULTS

The imbalance of important trace elements can accelerate SARS-CoV-2 neurovirulence and increase the neurotoxicity since many neurological processes can be associated with the homeostasis of metal and metalloproteins. Some studies involving animals and humans have suggested the synapse as a vulnerable region of the brain to neurological disorders after viral infection. Considering the combined evidence, some mechanisms have been suggested to understand the relationship between neurological disorders and imbalance of trace elements in the brain after viral infection.

CONCLUSION

Trace elements play important roles in viral infections, such as helping to activate immune cells, produce antibodies, and inhibit virus replication. However, the relationship between trace elements and virus infections is complex since the specific functions of several elements remain largely undefined. Therefore, there is still a lot to be explored to understand the biochemical mechanisms involved between trace elements and viral infections, especially in the brain.

The Effect of Circulating Zinc, Selenium, Copper and Vitamin K1 on COVID-19 Outcomes: A Mendelian Randomization Study

Background & Aims: Previous results from observational, interventional studies and in vitro experiments suggest that certain micronutrients possess anti-viral and immunomodulatory activities. In particular, it has been hypothesized that zinc, selenium, copper and vitamin K1 have strong potential for prophylaxis and treatment of COVID-19. We aimed to test whether genetically predicted Zn, Se, Cu or vitamin K1 levels have a causal effect on COVID-19 related outcomes, including risk of infection, hospitalization and critical illness. Methods: We employed a two-sample Mendelian Randomization (MR) analysis. Our genetic variants derived from European-ancestry GWAS reflected circulating levels of Zn, Cu, Se in red blood cells as well as Se and vitamin K1 in serum/plasma. For the COVID-19 outcome GWAS, we used infection, hospitalization or critical illness. Our inverse-variance weighted (IVW) MR analysis was complemented by sensitivity analyses including a more liberal selection of variants at a genome-wide sub-significant threshold, MR-Egger and weighted median/mode tests. Results: Circulating micronutrient levels show limited evidence of association with COVID-19 infection, with the odds ratio [OR] ranging from 0.97 (95% CI: 0.87-1.08, p-value = 0.55) for zinc to 1.07 (95% CI: 1.00-1.14, p-value = 0.06)-i.e., no beneficial effect for copper was observed per 1 SD increase in exposure. Similarly minimal evidence was obtained for the hospitalization and critical illness outcomes with OR from 0.98 (95% CI: 0.87-1.09, p-value = 0.66) for vitamin K1 to 1.07 (95% CI: 0.88-1.29, p-value = 0.49) for copper, and from 0.93 (95% CI: 0.72-1.19, p-value = 0.55) for vitamin K1 to 1.21 (95% CI: 0.79-1.86, p-value = 0.39) for zinc, respectively. Conclusions: This study does not provide evidence that supplementation with zinc, selenium, copper or vitamin K1 can prevent SARS-CoV-2 infection, critical illness or hospitalization for COVID-19.

Impact of Nutrition in the Management of Nutritional Status of Covid-19 Patients

Abstract:

The second outbreak of severe acute respiratory syndrome coronavirus (SARS-CoV-2) is of great concern due to its awful mortality and morbidity rate with decreasing nutritional status and poor lifestyle as well as noteworthy food crisis and affected economy of the world. Increasing food prices, food crisis, global hunger and decreasing availability and feasibility of food are the foremost causes of decreasing nutritional status, which increases the risk of susceptibility to infection and, in turn, leads to unfavorable outcomes of the diseases. Although, in times of the Covid- 19 pandemic, nutrition is of potential attention, and there is a requirement for more exploration in the field of nutrition for the prevention of diseases arising from coronavirus infection. Elderly and individuals with co-morbidity, such as respiratory diseases, cardiovascular diseases, diabetes mellitus and metabolic diseases, are more prone towards getting infected with the coronavirus. Good nutrition is mandatory for healthy immune responses, which can be improved by the inclusion of vitamin A, B6, B12, C, D, E, zinc, selenium, iron, copper and an antioxidant-rich diet.

Effects of Selenium Supplementation on Rumen Microbiota, Rumen Fermentation, and Apparent Nutrient Digestibility of Ruminant Animals: A Review

Enzymes excreted by rumen microbiome facilitate the conversion of ingested plant materials into major nutrients (e.g., volatile fatty acids (VFA) and microbial proteins) required for animal growth. Diet, animal age, and health affect the structure of the rumen microbial community. Pathogenic organisms in the rumen negatively affect fermentation processes in favor of energy loss and animal deprivation of nutrients in ingested feed. Drawing from the ban on antibiotic use during the last decade, the livestock industry has been focused on increasing rumen microbial nutrient supply to ruminants through the use of natural supplements that are capable of promoting the activity of beneficial rumen microflora. Selenium (Se) is a trace mineral commonly used as a supplement to regulate animal metabolism. However, a clear understanding of its effects on rumen microbial composition and rumen fermentation is not available. This review summarized the available literature for the effects of Se on specific rumen microorganisms along with consequences for rumen fermentation and digestibility. Some positive effects on total VFA, the molar proportion of propionate, acetate to propionate ratio, ruminal NH3-N, pH, enzymatic activity, ruminal microbiome composition, and digestibility were recorded. Because Se nanoparticles (SeNPs) were more effective than other forms of Se, more studies are needed to compare the effectiveness of synthetic SeNPs and lactic acid bacteria enriched with sodium selenite as a biological source of SeNPs and probiotics. Future studies also need to evaluate the effect of dietary Se on methane emissions.

Selenium-Containing Compound Ameliorates Lipopolysaccharide-Induced Acute Lung Injury via Regulating the MAPK/AP-1 Pathway

Abstract-Acute lung injury (ALI) is characterized by a series of inflammatory reactions and serves as the main cause of mortality in intensive care unit patients. Although great progress has been made in understanding the pathophysiology of ALI, there are no effective treatments in clinic. Recently, we have synthesized a selenium-containing compound, which possesses obvious anti-inflammatory activity. The aim of the present study is to evaluate the protective effects of the selenium-containing compound 34# in LPS-induced ALI in mice as well as its underlying mechanism. Compound 34# was found to inhibit LPS-induced macrophage inflammatory cytokine release. These effects were observed to be produced via suppression of the MAPK/AP-1 pathway. Compound 34# was also noted to attenuate the LPS-induced lung inflammation in mice with ALI. The corresponding results suggested that compound 34# possesses remarkable protective effects on LPS-induced ALI. Furthermore, the MAPK/AP-1 pathway may prove to be the underlying mechanism. Accordingly, compound 34# may serve as a potential candidate for the prevention of ALI.

Clinical Significance of Micronutrient Supplementation in Critically Ill COVID-19 Patients with Severe ARDS

The interplay between inflammation and oxidative stress is a vicious circle, potentially resulting in organ damage. Essential micronutrients such as selenium (Se) and zinc (Zn) support anti-oxidative defense systems and are commonly depleted in severe disease. This single-center retrospective study investigated micronutrient levels under Se and Zn supplementation in critically ill patients with COVID-19 induced acute respiratory distress syndrome (ARDS) and explored potential relationships with immunological and clinical parameters. According to intensive care unit (ICU) standard operating procedures, patients received 1.0 mg of intravenous Se daily on top of artificial nutrition, which contained various amounts of Se and Zn. Micronutrients, inflammatory cytokines, lymphocyte subsets and clinical data were extracted from the patient data management system on admission and after 10 to 14 days of treatment. Forty-six patients were screened for eligibility and 22 patients were included in the study. Twenty-one patients (95%) suffered from severe ARDS and 14 patients (64%) survived to ICU discharge. On admission, the majority of patients had low Se status biomarkers and Zn levels, along with elevated inflammatory parameters. Se supplementation significantly elevated Se (p = 0.027) and selenoprotein P levels (SELENOP; p = 0.016) to normal range. Accordingly, glutathione peroxidase 3 (GPx3) activity increased over time (p = 0.021). Se biomarkers, most notably SELENOP, were inversely correlated with CRP (r_s = −0.495), PCT (r_s = −0.413), IL-6 (r_s = −0.429), IL-1β (r_s = −0.440) and IL-10 (r_s = −0.461). Positive associations were found for CD8⁺ T cells (r_s = 0.636), NK cells (r_s = 0.772), total IgG (r_s = 0.493) and PaO₂/FiO₂ ratios (r_s = 0.504). In addition, survivors tended to have higher Se levels after 10 to 14 days compared to non-survivors (p = 0.075). Sufficient Se and Zn levels may potentially be of clinical significance for an adequate immune response in critically ill patients with severe COVID-19 ARDS.

Selenium (Se) plays a key role in the biological effects of some viruses: Implications for COVID-19

Host nutrition is an important factor affecting disease progression. Selenium (Se) is an essential trace element for the human body with anti-inflammatory, antioxidant, and immune effects, and Se deficiency increases RNA-virus replication and virulent mutations, which lead to more severe tissue damage and symptoms. Low Se status in the host may be an important cause of health complications induced by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In this article, we describe the metabolic mechanisms by which Se is involved in anti-inflammatory, antioxidant, and immune effects, and review the role and clinical effects of Se in viral infection. We then discuss the potential relationship between Se and coronavirus disease 2019 (COVID-19). The association between soil Se level and the incidence of COVID-19 was observed in different cities of Hubei Province. The incidence of COVID-19 was more than 10 times lower in Se-enriched cities (Enshi, Shiyan, and Xiangyang) than in Se-deficient cities (Suizhou and Xiaogan). Although the relationship between soil Se levels and the incidence of COVID-19 in Hubei still needs further study, these findings provide baseline information demonstrating the effect of Se levels on SARS-CoV-2, which could contribute to the prevention and management of COVID-19.

The effects of some essential and toxic metals/metalloids in COVID-19: A review

Thousands of studies have been conducted in order to understand in depth the characteristics of the novel coronavirus SARS-CoV-2, its infectivity and ways of transmission, and very especially everything related to the clinical and severity of the COVID-19, as well as the potential treatments. In this sense, the role that essential and toxic metals/metalloids have in the development and course of this disease is being studied. Metals/metalloids such as arsenic, cadmium, lead, mercury or vanadium, are elements with known toxic effects in mammals, while trace elements such as cobalt, copper, iron, manganese, selenium and zinc are considered essential. Given the importance of metals/metalloids in nutrition and human health, the present review was aimed at assessing the relationship between various essential and toxic metals/metalloids and the health outcomes related with the COVID-19. We are in the position to conclude that particular attention must be paid to the load/levels of essential trace elements in COVID-19 patients, mainly zinc and selenium. On the other hand, the exposure to air pollutants in general, and toxic metal/metalloids in particular, should be avoided as much as possible to reduce the possibilities of viral infections, including SARS-CoV-2.

Approaches to Nutritional Screening in Patients with Coronavirus Disease 2019 (COVID-19)

Malnutrition is common among severe patients with coronavirus disease 2019 (COVID-19), mainly elderly adults and patients with comorbidities. It is also associated with atypical presentation of the disease. Despite the possible contribution of malnutrition to the acquisition and severity of COVID-19, it is not clear which nutritional screening measures may best diagnose malnutrition in these patients at early stages. This is of crucial importance given the urgency and rapid progression of the disease in vulnerable groups. Accordingly, this review examines the available literature for different nutritional screening approaches implemented among COVID-19 patients, with a special focus on elderly adults. After a literature search, we selected and scrutinized 14 studies assessing malnutrition among COVID-19 patients. The Nutrition Risk Screening 2002 (NRS-2002) has demonstrated superior sensitivity to other traditional screening measures. The controlling nutritional status (CONUT) score, which comprises serum albumin level, cholesterol level, and lymphocytes count, as well as a combined CONUT-lactate dehydrogenase-C-reactive protein score expressed a predictive capacity even superior to that of NRS-2002 (0.81% and 0.92% vs. 0.79%) in midlife and elder COVID-19 patients. Therefore, simple measures based on routinely conducted laboratory investigations such as the CONUT score may be timely, cheap, and valuable alternatives for identifying COVID-19 patients with high nutritional risk. Mini Nutritional Assessment (MNA) was the only measure used to detect residual malnutrition and high malnutrition risk in remitting patients-MNA scores correlated with hypoalbuminemia, hypercytokinemia, and weight loss. Older males with severe inflammation, gastrointestinal symptoms, and pre-existing comorbidities (diabetes, obesity, or hypertension) are more prone to malnutrition and subsequently poor COVID-19 prognosis both during the acute phase and during convalescence. Thus, they are in need of frequent nutritional monitoring and support while detecting and treating malnutrition in the general public might be necessary to increase resilience against COVID-19.

Micronutrients early in critical illness, selective or generous, enteral or intravenous?

PURPOSE OF REVIEW

Micronutrients have essential antioxidant and immune functions, while low blood concentrations are frequently observed in critically ill patients. This has led to the concepts of complementation, repletion, or even pharmacological supplementation. Over the last three decades, many clinical studies have tested the latter strategy, with controversial or negative results. Therefore, this review aims at evaluating micronutrient-related interventions that are mandatory or need to be assessed in future trials or clinical registries in all or specific critically ill patients.

RECENT FINDINGS

In the critically ill, low plasma/serum micronutrient levels not always reflect a true deficiency in the absence of demonstrable losses. Current practices of micronutrient provision and monitoring in critical care, vary substantially across the world. Also, recent clinical trials testing high dose as monotherapy (selenium, thiamine, vitamin C, vitamin D) or in combination have failed to demonstrate clinical benefits in sepsis. However, these studies have not applied a physiological integrative approach of micronutrient action.

SUMMARY

Micronutrients are essential in nutrition but their administration and monitoring are difficult. So far, different well designed RCTs on intravenous and oral high dose micronutrient supplementation have been conducted. Nevertheless, very high-dose single micronutrients cannot be advocated at this stage in sepsis, or any other critical condition. By contrast, studies using combination of moderate doses of micronutrients in specific diseases, such as burns and trauma have been associated with improved outcomes. Intravenous administration seems to be the most efficient route. Future clinical trials need to integrate the physiology underlying the interconnected micronutrient activity, and choose more specific primary and secondary endpoints.