The Role of Vitamin C, Vitamin D, and Selenium in Immune System against COVID-19

Abstract

Low levels of micronutrients have been associated with adverse clinical outcomes during viral infections. Therefore, to maximize the nutritional defense against infections, a daily allowance of vitamins and trace elements for malnourished patients at risk of or diagnosed with coronavirus disease 2019 (COVID-19) may be beneficial. Recent studies on COVID-19 patients have shown that vitamin D and selenium deficiencies are evident in patients with acute respiratory tract infections. Vitamin D improves the physical barrier against viruses and stimulates the production of antimicrobial peptides. It may prevent cytokine storms by decreasing the production of inflammatory cytokines. Selenium enhances the function of cytotoxic effector cells. Furthermore, selenium is important for maintaining T cell maturation and functions, as well as for T cell-dependent antibody production. Vitamin C is considered an antiviral agent as it increases immunity. Administration of vitamin C increased the survival rate of COVID-19 patients by attenuating excessive activation of the immune response. Vitamin C increases antiviral cytokines and free radical formation, decreasing viral yield. It also attenuates excessive inflammatory responses and hyperactivation of immune cells. In this mini-review, the roles of vitamin C, vitamin D, and selenium in the immune system are discussed in relation to COVID-19.

Have Lifestyle Habits and Psychological Well-Being Changed among Adolescents and Medical Students Due to COVID-19 Lockdown in Croatia?

“…Closer studies are needed to elucidate the reasons behind various observed changes, focusing on availability of foods, stress-related eating and other factors, affecting behavior such as media recommendations and science news. Following those information, particular attention has been paid to the intake of micronutrients, including vitamin C and D during COVID-19 pandemic [44,45], since increased intake of fruit and vegetables has been recommended by several authors, in order to support the immune system [46,47].…”

Current Updates on Naturally Occurring Compounds Recognizing SARS-CoV-2 Druggable Targets

“…According to the authors, a significant decrease in intensive care unit stay and hospital mortality was observed in the vitamin C treated patients [ 44 ]. Overall, vitamin C seemed to possess relevant pharmacological properties against severe respiratory infections, including COVID-19 [ 45 , 46 ]. Several clinical trials, assessing the efficacy of high dose vitamin C infusion, are still ongoing and will provide more definitive evidence.…”

“…Overall, vitamin C seemed to possess relevant pharmacological properties against severe respiratory infections, including COVID-19 [45,46]. Several clinical trials, assessing the efficacy of high dose vitamin C infusion, are still ongoing and will provide more definitive evidence.…”

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

“…GPx and TrxR are important to endothelial-cell function. Supplementation of selenite can enhance the activity of GPX and TrxR, thereby reducing the oxidative damage to human endothelial cells ( Hiffler et al, 2020 ; Bae et al, 2020 ). In addition, up to 20% of COVID-19 cases develop severe disease with fever and pneumonia, thereby inducing acute respiratory distress syndrome (ARDS) ( Moore & June, 2020 ), which is a sepsis-related process caused by a cytokine storm due to NF- k B activation by the virus ( Manzanares et al, 2021 ).…”

“…Some essential trace elements, such as zinc, selenium (Se), and iron, are thought to be helpful in immune-system regulation ( Moghaddam et al, 2020 ). Since severe alveolar epithelial-cell damage with nonspecific innate immune response, swelling, hyperplasia, and necrosis have been found in COVID-19 patients ( Zhang et al, 2020a ), nutritional therapy has been suggested for some COVID-19 patients ( Bae et al, 2020 ; Méplan et al, 2020 ).…”