Effect of Vitamin-D on COVID-19: A Review

Vitamin-D deficiency is a common yet understated problem. A number of people are at a risk of its deficiency while many others go undetected with the deficiency. The novel corona virus, an RNA virus, has run its rampant course across the globe affecting millions for the worse. COVID-19, a disease caused as a result of the infection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has shown to produce severe lower respiratory symptoms. This has so far resulted into a reported death count of more than 4.9 million worldwide. More than 4.5 lacs were affected in India. COVID-19 affects numerous other organs such as the liver, brain, kidney and heart. Dosage of Vitamin-D regularly, during the treatment and as a pre-emptive measure have all shown to reduce respiratory tract inflammation. Low plasma 25(OH)D levels appear to be an independent risk factor for COVID‐19 infection and hospitalization. Administration of a large dose of Calcifediol or what is also known as 25-hydroxyVitamin-D , a main metabolite of the Vitamin-D endocrine system, noticeably lessened the need for ICU treatment of patients requiring hospitalization after being tested positive for COVID-19. Elevated levels of Vitamin-D in body could decrease the length of hospital stays and reduce the intensity of the COVID 19 infection. In many COVID-19 patients the T regulatory lymphocytes (Tregs) levels are found to be low. These low levels can be elevated by Vitamin-D supplementation. Low levels of Vitamin-D have also been associated with increased inflammatory cytokines and a noticeably increased risk of pneumonia and viral upper respiratory tract infections. While further large-scale studies are required to provide concrete answers, the severity of the disease has been shown to be reduced and Vitamin-D can potentially be used as a supplementary treatment against Covid-19 and also as a precaution against the same. These results are significant and should not be ignored.