As the coronavirus disease 2019 (COVID-19) pandemic evolves, many agents have been tested to see if they can reduce the risk of severe disease and death among infected patients. One of the widely explored agents that have been shown to reduce disease progression is vitamin D.
Caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), COVID-19 is primarily a respiratory illness but is known to affect other parts of the body, from the gastrointestinal tract to the central nervous system. It can also overwhelm the immune system in severe cases, hence the scientific interest in whether immune-boosting supplementation can help fight off the infection.
Researchers at the Tabriz Health Services Management Research Center, Tabriz University of Medical Sciences, and the Shahid Beheshti University of Medical Sciences showed that prescribing vitamin D supplementation to COVID-19 patients seems to decrease the mortality rate, the severity of the disease, and serum levels of inflammatory markers.
Vitamin D and COVID-19
The coronavirus pandemic has spread to 191 countries and regions, with over 86.47 million cases and 1.86 million deaths. With the global spread of the SARS-CoV-2 and rise in infection and mortality toll, efficient management of the illness has become an absolute priority.
Many scientists have since studied various agents to determine those that can prevent disease progression and COVID-19-related death. Several studies have suggested the positive impact of vitamin D on COVID-19 patients.
Vitamin D is a fat-soluble micronutrient that could facilitate the function of the immune system. In the past, studies have shown the potential link between vitamin D deficiency and severe outcomes in COVID-19 patients
This systematic review aims to evaluate the effects of vitamin D supplementation on clinical outcomes and mortality rate of COVID-19 patients.
Even before the current pandemic, the immunomodulatory role of vitamin D has been studied in the treatment of other upper respiratory infections. Vitamin D can help regulate the immune system, thanks to receptors found in various innate immune system cells. The vitamin can also suppress the adaptive immune response in the affected lung epithelial cells, hence, preventing the pro-inflammatory agents' harm on the affected sites.
Lastly, vitamin D plays an important role in protecting against the direct damage of the inflammatory factors, which are released during viral diseases.
The study, published on the pre-print medRxiv* server, highlights the role of vitamin D supplementation in reducing the risk of severe illness and death due to COVID-19.
The team conducted a systematic review to arrive at the study findings, including research from PubMed, Web of Knowledge, Scopus, Embase, The Cochrane Library, and Ovid up to December 16, 2020.
The team has found that in three of the studies, the survival and mortality rate of the patients were studied, revealing that a significantly lower mortality rate among the intervention groups compared to the control groups. Moreover, two of the studies showed that the clinical outcomes based on the World Health Organization (WHO) Ordinal Scale for Clinical Improvement (OSCI) score for COVID-19, were lower in patients who received vitamin D supplementation.
Further, a study showed that there is a lower rate of intensive care unit (ICU) admission among those who received vitamin D, and another study reported a marked decrease in serum levels of fibrinogen, which increases in levels in any condition that causes inflammation or tissue damage.
Vitamin D supplementation seems to decrease the mortality rate, the severity of the disease, and the inflammatory markers' levels among the COVID-19 infected patients, leading to a better prognosis and increased survival… More studies should be conducted to determine the optimum dosage and route of vitamin D supplementation and further investigate the potential prophylactic effects."
To date, many countries report surging COVID-19 cases, including the United States and the United Kingdom, with over 21 million and 2.78 million cases, respectively. Since October 2020, the UK has experienced a second wave of the pandemic, with a new variant that is thought to be around 70% more infectious now circulating.
Knowing more about potential therapies to reduce the risk of death tied to COVID-19 is important as the world waits for the full deployment of COVID-19 vaccines.
medRxiv publishes preliminary scientific reports that are not peer-reviewed and, therefore, should not be regarded as conclusive, guide clinical practice/health-related behavior, or treated as established information.