Vitamin D: A Potential Prophylactic and Therapeutic Agent against COVID-19

The COVID-19 pandemic caused by the novel SARS-CoV-2 is having a drastic and an unprecedented impact on public health and human life. In the spectrum of clinical symptoms, long-lasting residual effects and sheer number of fatalities, the Severe Acute Respiratory Syndrome Coronavirus-1 (SARS-CoV-1) or Middle East Respiratory Syndrome (MERS) epidemics that preceded it pale in comparison. The coronavirus of 2019, SARS-CoV-2, has infected approximately 3% of the world's population and killed about 2% of the infected. Studies indicate that 80% of COVID-19 patients in the West exhibit vitamin D deficiency and suffer from higher levels of inflammatory responses supporting a role for vitamin D status in COVID-19 risk. Vitamin D is active in many cells and tissues controlling an enormous number of genes, including those associated with infections, autoimmune diseases, and cancers. This vital micronutrient can enhance antioxidant production, raise cellular immunity, and dampen an overreactive immune response. It also exhibits immunomodulatory effects on angiotensin-converting enzyme 2 (ACE-2) receptors potentially rendering protective functions against acute lung injuries, including COVID-19 infection. Therefore, vitamin D's prophylactic and therapeutic roles against COVID-19 may be potent and medically advisable. However, there are also some articles that undermine its positive effect against COVID-19. In this chapter, I will examine the evidence supporting vitamin D's role in prophylaxis and therapeutic administration against SARS-CoV-2 infection and COVID-19. © The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Switzerland AG 2022.

Optimization of ultrasonication-assisted extraction conditions using RSM-I-Optimal experimental design to recover vitamin D2 and K1 from selected green leafy vegetable samples

This study employed the response surface methodology to optimize the extraction conditions for recovering vitamins D2 and K1 from green leafy vegetables using ultrasonication-assisted extraction. The vitamin content was determined using an Accucore C18 column and a UPLC-Q-ToF/MS method. An RSM-I-Optimal design was used for designing the experiment to find the best combination of solvent level (mL), sonication time (min), sonication frequency (kHz), and temperature (°C). The experimental data from a 25-sample set were fitted to a second-order polynomial equation using multiple regression analysis. The extraction models had R2 values of 0.895 and 0.896, respectively, and the probability values (p < 0.0001) indicated that the regression model was highly significant. The optimal extraction conditions were: solvent level of 65 mL, sonication time of 45 min, sonication frequency of 70 kHz, and temperature of 45 °C. Under these conditions, the predicted recovery (%) values for vitamins D2 and K1 were 90.7% and 90.4%, respectively. This study has the potential to use the reported extraction method for routine quantification of vitamins D2 and K1 in the laboratory using UPLC-Q-ToF/MS.

The One-Hundred-Year Anniversary of the Discovery of the Sunshine Vitamin D3: Historical, Personal Experience and Evidence-Based Perspectives.

The discovery of a fat-soluble nutrient that had antirachitic activity and no vitamin A activity by McCollum has had far reaching health benefits for children and adults. He named this nutrient vitamin D. The goal of this review and personal experiences is to give the reader a broad perspective almost from the beginning of time for how vitamin D evolved to became intimately involved in the evolution of land vertebrates. It was the deficiency of sunlight causing the devastating skeletal disease known as English disease and rickets that provided the first insight as to the relationship of sunlight and the cutaneous production of vitamin D3. The initial appreciation that vitamin D could be obtained from ultraviolet exposure of ergosterol in yeast to produce vitamin D2 resulted in the fortification of foods with vitamin D2 and the eradication of rickets. Vitamin D3 and vitamin D2 (represented as D) are equally effective in humans. They undergo sequential metabolism to produce the active form of vitamin D, 1,25-dihydroxyvitamin D. It is now also recognized that essentially every tissue and cell in the body not only has a vitamin D receptor but can produce 1,25-dihydroxyvitamin D. This could explain why vitamin D deficiency has now been related to many acute and chronic illnesses, including COVID-19.

Implementation strategies for improving vitamin D status and increasing vitamin D intake in the UK: current controversies and future perspectives: proceedings of the 2nd Rank Prize Funds Forum on vitamin D.

A multi-disciplinary expert group met to discuss vitamin D deficiency in the UK and strategies for improving population intakes and status. Changes to UK Government advice since the 1st Rank Forum on Vitamin D (2009) were discussed, including rationale for setting a reference nutrient intake (10 µg/d; 400 IU/d) for adults and children (4+ years). Current UK data show inadequate intakes among all age groups and high prevalence of low vitamin D status among specific groups (e.g. pregnant women and adolescent males/females). Evidence of widespread deficiency within some minority ethnic groups, resulting in nutritional rickets (particularly among Black and South Asian infants), raised particular concern. Latest data indicate that UK population vitamin D intakes and status reamain relatively unchanged since Government recommendations changed in 2016. Vitamin D food fortification was discussed as a potential strategy to increase population intakes. Data from dose-response and dietary modelling studies indicate dairy products, bread, hens' eggs and some meats as potential fortification vehicles. Vitamin D3 appears more effective than vitamin D2 for raising serum 25-hydroxyvitamin D concentration, which has implications for choice of fortificant. Other considerations for successful fortification strategies include: (i) need for 'real-world' cost information for use in modelling work; (ii) supportive food legislation; (iii) improved consumer and health professional understanding of vitamin D's importance; (iv) clinical consequences of inadequate vitamin D status and (v) consistent communication of Government advice across health/social care professions, and via the food industry. These areas urgently require further research to enable universal improvement in vitamin D intakes and status in the UK population.

Study of ergocalciferol and cholecalciferol (Vitamin D): Modeled optical properties and optical detection using absorption and Raman spectroscopy.

The task of assembling and calculating spectrally significant lines of Vitamin D2 and D3 is related to a wider goal of establishing if it is possible to develop non-invasive optical sensors for these substances present at concentrations on the order of tens of nmol/L. Such a non-invasive in vivo sensor would be helpful for medical considerations, among others, related to multiple sclerosis prevention, reduced risk of mortality in D3-treated acute in-patients admitted with COVID 19, systemic infection, acute respiratory tract infections, including epidemic influenza, community-acquired pneumonia at concentrations <50nmol/L(<20ng/mL), dental health (90-100nmol/L) of 25(OH) D, general health and others. Currently, to determine the concentration of these substances, it is necessary to draw a sample from a vein in ambulatory settings and analyse the sample with the gold standard of mass spectroscopy or immunoassay. In this article Vitamin D optical properties are studied by density functional theory calculations, compared to reported data, and the new calculated and measured D2 and D3 optical absorption lines are presented, as well as the calculations compared with spectral measurements of optical transmission, FTIR ATR and Raman spectra.

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