Clinical evidence of vitamin D for COVID-19 prophylaxis and reduction of severity

Abstract

The COVID-19 pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has had a great impact on socioeconomic activity worldwide and even required new lifestyles. Regarding COVID-19 prophylaxis, it is important to take measures to reduce the risk of exposure to SARS-CoV-2 as well as to increase the resistance to infection by modulating the immune system. Micronutrients such as vitamins and minerals are essential for maintaining immunity in the human body. Previous studies have shown a significant correlation between low vitamin D levels and increased risk of respiratory infections. In addition, it has been reported that the administration of vitamin D supplements reduces morbidities of seasonal influenza and other respiratory tract infections. In addition, a low level of vitamin D is found to be the underlying condition in the high-risk groups of COVID-19. Cross-sectional studies in European countries showed that vitamin D levels were negatively correlated with morbidity, mortality, and the severity of COVID-19. There are still many unclear points regarding susceptibility to infection by the virus and the aggravation of COVID-19. However, based on the currently available evidence, supplementation of vitamin D with a daily dose of 1,000 IU to achieve optimal nonspecific immunity in the human body should be considered as an integrative and complementary therapy for COVID-19 prophylaxis.