¹Michael Ausi, MD²Shivaughn Hem-Lee-Forsyth, Ph.D., MPH

¹,²Department of Public Health and Preventive Medicine, St. George’s University

This narrative review explores the protective value of Vitamin D (VD) and its metabolites, such as Vitamin D2 (VD2) and Vitamin D3 (VD3), and their preventive health potentials backed by evidence-based medicine against viral respiratory illnesses (VRI). With the recent events of late 2019, a severe acute respiratory illness began to sweep the globe. This SARS illness was of coronavirus-2 variant known as SARS-CoV-2 (COVID-19). With COVID-19 in mind, the purpose of this paper was to explore a preventative health model utilizing evidence-based medical research to safeguard against similar viral catastrophes. The knowledge gained is essential for the future education of the general population and necessary for a more preemptive and protective approach to VRIs.

Google Scholar, PubMed, and DuckDuckgo were the most often utilized internet search engines and databases to collect sources. Twelve evidence-based medical articles were selected based on specific inclusionary and exclusionary criteria. More specifically, eleven systematic-review and meta-analyses (SRMA) and one Randomized Controlled Trial (RCT) were selected. The data extracted from the eleven articles were analyzed to understand the relationship between VD, VD3, and Viral Respiratory illnesses (VRIs).

VD is known to have various protective actions on the immune system (IS). First, VD activates gene transcription upon innate immune cells to increase viral defensive proteins such as Defensins and Cathelicidins (Laaski, 2011; Liu, 2006; NIH, 2020). More importantly, VD down-regulates certain specific adaptive immune cells named T helper 2 (Th2). The Th2 cellular pathway indirectly downregulates T helper 1 (Th1), cell pro-inflammatory cytokine storms, thus assisting with viral clearance (Huang, Wang, Li et al., 2020). More EBM research displays an inverse relationship between VD status and VRI, like incidences, severity, and duration of VRIs (Abioye, Bromage & Fawz 2021).

Recommendations for future research were presented to understand VD better and its possible use as a potential therapeutic or preventive medicine modality for the public. Proposals on health policy changes within health agencies like the United States Preventative Task Force (USPTF) were also provided. Changes included mandatory health VD screens tables and their metabolites for patients of different ages and breeds to achieve proper VRI protection to prevent future pandemics.

Calciferol deficiency, Vitamin D, Vitamin D3, viral respiratory illness, COVID-19 pandemic, preventative health

1) Abioye, A. I., Bromage, S., & Fawz, W. (2021, January 1). Effect of micronutrient supplements on influenza and other respiratory tract infections among adults: a systematic review and meta-analysis. BMJ Global Health. https://gh.bmj.com/content/6/1/e003176

2) Castillo, M., Costa, L., & Barrios, J. (2020, October 1). Effect of calcifediol treatment and best available therapy versus best available therapy on intensive care unit admission and mortality among patients hospitalized for COVID-19-19: A pilot randomized clinical study. ScienceDirect. https://www.sciencedirect.com/science/article/abs/pii/S0960076020302764/?oRef=mixi

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4) Goodall, E. C. (2014, May 19). Vitamin D3 and gargling for the prevention of upper respiratory tract infections: a randomized controlled trial. BMC Infectious Diseases. https://bmcinfectdis.biomedcentral.com/articles/10.1186/1471- 2334-14-273#citeas

5) Grant, W. B. (2020, April 2). Evidence that Vitamin D Supplementation Could Reduce Risk of Influenza and COVID-19-19 Infections and Deaths. MDPI. https://www.mdpi.com/2072-6643/12/4/988

6) Hernández, J. L., Nan, D., & Fernandez-Ayala, M. (2020, October 27). Vitamin D Status in Hospitalized Patients with SARS- CoV-2 Infection. OUP Academic. https://academic.oup.com/jcem/advance-article/doi/10.1210/clinem/dgaa733/5934827

7) Huang, C., Wang, Y., & Li, X. (2020, February 15). Clinical features of patients infected with 2019 novel coronavirus in Wuhan, China. ScienceDirect. https://www.sciencedirect.com/science/article/abs/pii/S0140673620301835

8) Jolliffe, D. A., Camargo Jr, C. A., & Sluyter, J. D. (2021, May 1). Vitamin D supplementation to prevent acute respiratory infections: a systematic review and meta-analysis of aggregate data from randomized controlled trials. ScienceDirect. https://www.sciencedirect.com/science/article/pii/S2213858721000516

9) Laaksi, I. (2011, November 25). Vitamin D and respiratory infection in adults | Proceedings of the Nutrition Society. Cambridge Core. https://www.cambridge.org/core/journals/proceedings-of-the-nutrition-society/article/vitamin-d-and- respiratory-infection-in-adults/F0E08A242EBBE125087C8A7F65B1C6CC

10) Lemire, J. M. (1984, May). 1,25-dihydroxyvitamin D3 suppresses human T helper/inducer lymphocyte activity in vitro. PubMed. https://pubmed.ncbi.nlm.nih.gov/3156926/

11) Liu, P. T. (2006, March 24). Toll-Like Receptor Triggering of a Vitamin D-mediated Human Antimicrobial Response. Science. https://science.sciencemag.org/content/311/5768/1770.abstract

12) Liu, N., Sun, J., & Wang, X. (2021, March 1). Low vitamin D status is associated with coronavirus disease 2019 outcomes: a systematic review and meta-analysis. ScienceDirect. https://www.sciencedirect.com/science/article/pii/S120197122032600X

13) Martineau, A. R. (2017, February 15). Vitamin D supplementation to prevent acute respiratory tract infections: systematic review and meta-analysis of individual participant data. The BMJ. https://www.bmj.com/content/356/bmj.i6583

14) Meltzer, D. O. (2020, September 3). Association of Vitamin D Status and Other Clinical Characteristics With COVID-19-19 Test Results. Infectious Diseases | JAMA Network Open | JAMA Network. https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2770157

15) NIH, Office of Dietary Supplements. (2020, October 9). Office of Dietary Supplements - Vitamin D. Ods.Od.Nih.Gov. https://ods.od.nih.gov/factsheets/Vitamin%20D-HealthProfessional/

16) Nurshad Ali, N. A. (2020, October). Role of vitamin D in preventing of COVID-19-19 infection, progression, and severity. ScienceDirect. https://www.sciencedirect.com/science/article/pii/S1876034120305311

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20) Sharifi, A., Vahedi, H., Nedjat, S., Rafiei, H., & Hosseinzadeh-Attar, M. J. (2019, July). Effect of single-dose injection of vitamin D on immune cytokines in ulcerative colitis patients: a randomized placebo-controlled trial. PubMed. https://pubmed.ncbi.nlm.nih.gov/31274211/

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VOLUME 04 ISSUE 10 OCTOBER 2021