Vitamin D attenuates COVID-19 complications via modulation of proinflammatory cytokines, antiviral proteins, and autophagy

Abstract

Introduction : Global emergence of coronavirus disease-19 (COVID-19) has clearly shown variable severity, mortality, and frequency between and within populations worldwide. These striking differences have made many biological variables attractive for future investigations. One of these variables, vitamin D, has been implicated in COVID-19 with rapidly growing scientific evidence. Areas covered : The review intended to systematically explore the sources, and immunomodulatory role of vitamin D in COVID-19. Search engines and data sources including Google Scholar, PubMed, NCBI, Scopus, and Web of Science were used for data collection. The search terms used were Vitamin D, COVID-19, immune system, and antiviral mechanism. Overall, 232 sources of information were collected and 188 were included in this review. Expert opinion : Interaction of vitamin D and vitamin D receptor (VDR) triggers the cellular events to modulate the immune system by regulation of many genes. Vitamin D operates as a double-edged sword against COVID-19. First, in macrophages, it promotes the production of antimicrobial and antiviral proteins like β-defensin 2 and cathelicidin, and these proteins inhibit the replication of viral particles and promote the clearance of virus from the cells by autophagy. Second, it suppresses cytokine storm and inflammatory processes in COVID-19.

A correlational analysis of COVID-19 incidence and mortality and urban determinants of vitamin D status across the London boroughs

“…Whilst our observational study cannot confirm causative biological links between exposure to air pollutants and increased risk of COVID-19, previous research has highlighted that PM 10 promotes lung inflammation, and plays a pathological role in the development of lung disorders such as asthma, but also respiratory viruses 70 , 71 . Furthermore, increased exposure to PM 10 has also been linked with reduced systemic vitamin D levels 36 , 72 , and vitamin D has been suggested to have a direct role in reducing complications from COVID-19 via several biological mechanisms 73 . Therefore, increased exposure to PM 10 could contribute in multiple ways to a higher risk of acquiring COVID-19 with more severe outcomes.…”

Factors Modulating COVID-19: A Mechanistic Understanding Based on the Adverse Outcome Pathway Framework

“…Thus, low vitamin D status may impair the trapping protective mechanism of sACE2 [ 221 ]. Furthermore, vitamin D deficiency has been shown to reduce the expression of antimicrobial peptides (β-defensin, cathelicidin), which act against enveloped viruses [ 222 , 223 ]. Decreased sACE2 and cellular viral defense might be some mechanisms explaining how low vitamin D modulate SARS-CoV-2 infectibility.…”

The role of sheep’s milk bioactive substances in the prevention of metabolic and viral diseases

“…In human nutrition, milk and dairy products are the primary sources of fat-soluble vitamins. This group includes vitamin D, which improves the immune response against bacteria, fungi, parasites and viruses (Gilani et al, 2022). The outbreak of the SARS-CoV-2 coronavirus pandemic highlighted the role of vitamin D and its content in food products.…”

“…The risk of COVID-19 infection is associated with vitamin D deficiency. Vitamin D inhibits the cytokine storm and inflammatory processes associated with COVID-19 disease (Gilani et al, 2022), while in macrophages, it promotes the production of "antimicrobial" and "antiviral" proteins such as β-defensin 2 and cathelicidin that inhibit viral replication and promote its removal from cells by autophagy (Gilani et al, 2022). All these factors reduce the severity of the disease and shorten the hospitalisation period.…”