Selenium as a Bioactive Micronutrient in the Human Diet and Its Cancer Chemopreventive Activity.
This review answers the question of why selenium is such an important trace element in the human diet. Daily dietary intake of selenium and its content in various food products is discussed in this paper, as well as the effects of its deficiency and excess in the body. Moreover, the biological activity of selenium, which it performs mainly through selenoproteins, is discussed. These specific proteins are responsible for thyroid hormone management, fertility, the aging process, and immunity, but their key role is to maintain a redox balance in cells. Furthermore, taking into account world news and the current SARS-CoV-2 virus pandemic, the impact of selenium on the course of COVID-19 is also discussed. Another worldwide problem is the number of new cancer cases and cancer-related mortality. Thus, the last part of the article discusses the impact of selenium on cancer risk based on clinical trials (including NPC and SELECT), systematic reviews, and meta-analyses. Additionally, this review discusses the possible mechanisms of selenium action that prevent cancer development.
Potential molecular mechanisms of zinc- and copper-mediated antiviral activity on COVID-19.
Nutrition research (New York, N.Y.). 2021;:109-128
Novel coronavirus disease 2019 (COVID-19) has spread across the globe; and surprisingly, no potentially protective or therapeutic antiviral molecules are available to treat severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection. However, zinc (Zn) and copper (Cu) have been shown to exert protective effects due to their antioxidant, anti-inflammatory, and antiviral properties. Therefore, it is hypothesized that supplementation with Zn and Cu alone or as an adjuvant may be beneficial with promising efficacy and a favorable safety profile to mitigate symptoms, as well as halt progression of the severe form of SARS-CoV-2 infection. The objective of this review is to discuss the proposed underlying molecular mechanisms and their implications for combating SARS-CoV-2 infection in response to Zn and Cu administration. Several clinical trials have also included the use of Zn as an adjuvant therapy with dietary regimens/antiviral drugs against COVID-19 infection. Overall, this review summarizes that nutritional intervention with Zn and Cu may offer an alternative treatment strategy by eliciting their virucidal effects through several fundamental molecular cascades, such as, modulation of immune responses, redox signaling, autophagy, and obstruction of viral entry and genome replication during SARS-CoV-2 infection.
A literature review on beneficial role of vitamins and trace elements: Evidence from published clinical studies.
Journal of trace elements in medicine and biology : organ of the Society for Minerals and Trace Elements (GMS). 2021;:126789
COVID-19 is a kind of SARS-CoV-2 viral infectious pneumonia. This research aims to perform a bibliometric analysis of the published studies of vitamins and trace elements in the Scopus database with a special focus on COVID-19 disease. To achieve the goal of the study, network and density visualizations were used to introduce an overall picture of the published literature. Following the bibliometric analysis, we discuss the potential benefits of vitamins and trace elements on immune system function and COVID-19, supporting the discussion with evidence from published clinical studies. The previous studies show that D and A vitamins demonstrated a higher potential benefit, while Selenium, Copper, and Zinc were found to have favorable effects on immune modulation in viral respiratory infections among trace elements. The principles of nutrition from the findings of this research could be useful in preventing and treating COVID-19.
Selenium Deficiency Due to Diet, Pregnancy, Severe Illness, or COVID-19-A Preventable Trigger for Autoimmune Disease.
International journal of molecular sciences. 2021;(16)
The trace element selenium (Se) is an essential part of the human diet; moreover, increased health risks have been observed with Se deficiency. A sufficiently high Se status is a prerequisite for adequate immune response, and preventable endemic diseases are known from areas with Se deficiency. Biomarkers of Se status decline strongly in pregnancy, severe illness, or COVID-19, reaching critically low concentrations. Notably, these conditions are associated with an increased risk for autoimmune disease (AID). Positive effects on the immune system are observed with Se supplementation in pregnancy, autoimmune thyroid disease, and recovery from severe illness. However, some studies reported null results; the database is small, and randomized trials are sparse. The current need for research on the link between AID and Se deficiency is particularly obvious for rheumatoid arthritis and type 1 diabetes mellitus. Despite these gaps in knowledge, it seems timely to realize that severe Se deficiency may trigger AID in susceptible subjects. Improved dietary choices or supplemental Se are efficient ways to avoid severe Se deficiency, thereby decreasing AID risk and improving disease course. A personalized approach is needed in clinics and during therapy, while population-wide measures should be considered for areas with habitual low Se intake. Finland has been adding Se to its food chain for more than 35 years-a wise and commendable decision, according to today's knowledge. It is unfortunate that the health risks of Se deficiency are often neglected, while possible side effects of Se supplementation are exaggerated, leading to disregard for this safe and promising preventive and adjuvant treatment options. This is especially true in the follow-up situations of pregnancy, severe illness, or COVID-19, where massive Se deficiencies have developed and are associated with AID risk, long-lasting health impairments, and slow recovery.
Supplementation of the population during the COVID-19 pandemic with vitamins and micronutrients - how much evidence is needed?
Swiss medical weekly. 2021;:w20522
An exploratory study of selenium status in healthy individuals and in patients with COVID-19 in a south Indian population: The case for adequate selenium status.
Nutrition (Burbank, Los Angeles County, Calif.). 2021;:111053
The acute respiratory syndrome coronavirus-2 (SARS-CoV-2) pandemic has affected millions of individuals, causing major health and economic disruptions worldwide. The pandemic is still raging, with a second and third wave in a few countries, while new infections steadily rise in India. Nutrition and immune status are two critical aspects of fighting the virus successfully. Recently, selenium status was reported to positively correlate with the survival of patients with COVID-19 compared with non-survivors. We analyzed the blood serum levels in 30 apparently healthy individuals and in 30 patients with confirmed COVID-19 infection in the southern part of India. The patients showed significantly lower selenium levels of 69.2 ± 8.7 ng/mL than controls 79.1 ± 10.9 ng/mL. The difference was statistically significant (P = 0.0003). Interestingly, the control group showed a borderline level of selenium, suggesting that the level of this micronutrient is not optimum in the population studied. The results of this exploratory study pave the way for further research in a larger population and suggest that selenium supplementation may be helpful in reducing the effects of the virus.
Obesity, malnutrition, and trace element deficiency in the coronavirus disease (COVID-19) pandemic: An overview.
Nutrition (Burbank, Los Angeles County, Calif.). 2021;:111016
The world is currently facing the coronavirus disease (COVID-19) pandemic which places great pressure on health care systems and workers, often presents with severe clinical features, and sometimes requires admission into intensive care units. Derangements in nutritional status, both for obesity and malnutrition, are relevant for the clinical outcome in acute illness. Systemic inflammation, immune system impairment, sarcopenia, and preexisting associated conditions, such as respiratory, cardiovascular, and metabolic diseases related to obesity, could act as crucial factors linking nutritional status and the course and outcome of COVID-19. Nevertheless, vitamins and trace elements play an essential role in modulating immune response and inflammatory status. Overall, evaluation of the patient's nutritional status is not negligible for its implications on susceptibility, course, severity, and responsiveness to therapies, in order to perform a tailored nutritional intervention as an integral part of the treatment of patients with COVID-19. The aim of this study was to review the current data on the relevance of nutritional status, including trace elements and vitamin status, in influencing the course and outcome of the disease 3 mo after the World Health Organization's declaration of COVID-19 as a pandemic.