ABSTRACT
The world is currently facing the COVID-19 pandemic, caused by the novel Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2). Due to a lack of specific treatment and prophylaxis, protective health measures that can reduce infection severity and COVID-19 mortality are urgently required. Clinical and epidemiological studies have shown that vitamin D deficiency can be linked to an increased risk of viral infection, including COVID-19. Therefore, in this review, we looked at various possible roles of vitamin D in reducing the risk of COVID-19 infection and severity. We describe in this article that individuals at high risk of vitamin D deficiency should consider taking vitamin D supplements to keep optimal concentrations. Moreover, we discuss different possible mechanisms by which vitamin D can efficiently reduce the risk of infections through modulation of innate and adaptive immunity against various types of infections. It is advisable to perform further studies addressing the observed influence of vitamin D levels to reduce the risk of COVID-19 infection and mortality.
Subject(s)
COVID-19 Drug Treatment , Protective Agents/therapeutic use , SARS-CoV-2 , Vitamin D Deficiency/prevention & control , Vitamin D/therapeutic use , Adaptive Immunity/drug effects , Bystander Effect , COVID-19/immunology , COVID-19/mortality , COVID-19/transmission , Dietary Supplements , Humans , Immunity, Innate/drug effects , Protective Agents/administration & dosage , Severity of Illness Index , Vitamin D/administration & dosage , Vitamin D Deficiency/epidemiology , Vitamin D Deficiency/immunologySubject(s)
Betacoronavirus , Coronavirus Infections/drug therapy , Coronavirus Infections/epidemiology , Pneumonia, Viral/drug therapy , Pneumonia, Viral/epidemiology , Protective Agents/therapeutic use , Vitamin D/therapeutic use , Vitamins/therapeutic use , Angiotensin-Converting Enzyme 2 , COVID-19 , Coronavirus Infections/virology , Dietary Supplements , Host-Pathogen Interactions/drug effects , Humans , Pandemics , Peptidyl-Dipeptidase A/metabolism , Pneumonia, Viral/virology , Protective Agents/administration & dosage , Protective Agents/pharmacology , Renin-Angiotensin System/drug effects , SARS-CoV-2 , Signal Transduction/drug effects , Spike Glycoprotein, Coronavirus/metabolism , Vitamin D/administration & dosage , Vitamin D/pharmacology , Vitamins/administration & dosage , Vitamins/pharmacology , COVID-19 Drug TreatmentABSTRACT
It has long been suggested that NO may inhibit an early stage in viral replication. Furthermore, in vitro tests have shown that NO inhibits the replication cycle of severe acute respiratory syndrome coronavirus. Despite smoking being listed as a risk factor to contract Covid-19, only a low proportion of the smokers suffered from SARS-corona infection in China 2003, and from Covid-19 in China, Europe and the US. We hypothesize, that the intermittent bursts of high NO concentration in cigarette smoke may be a mechanism in protecting against the virus. Mainstream smoke from cigarettes contains NO at peak concentrations of between about 250 ppm and 1350 ppm in each puff as compared to medicinal use of no more than 80 to a maximum of 160 ppm. The diffusion of NO through the cell wall to reach the virus should be significantly more effective at the very high NO concentration in the smoke, according to classic laws of physics. The only oxide of nitrogen in the mainstream smoke is NO, and the NO2 concentration that is inhaled is very low or undetectable, and methemoglobin levels are lower in smokers than non-smokers, reasonably explained by the breaths of air in between the puffs that wash out the NO. Specialized iNO machines can now be developed to provide the drug intermittently in short bursts at high concentration dose, which would then provide both a preventative drug for those at high risk, as well as an effective treatment, without the health hazards associated with smoking.