Critical analysis on the use of cholecalciferol as a COVID-19 intervention: a narrative review

Abstract

In December 2019, a disease caused by a new coronavirus, COVID-19, caused an epidemic in China and then spread rapidly around the world. 1 The clinical spectrum of the disease caused by the new coronavirus is broad, covering asymptomatic infection, mild infection of the upper respiratory tract and severe pneumonia with respiratory failure. COVID-19 has led many patients to require hospitalization and semi-intensive or intensive care. 2,3 Most complications and deaths have been reported among elderly patients with evidence of underlying diseases, such as cardiovascular, lung or kidney diseases, or cancer. 1 So far, the absence of a vaccine for the new coronavirus has led people around the world to seek a variety of therapeutic alternatives. Consequently, sales of several drugs that have not been proven to be effective for treating COVID-19 have increased. In Brazil, one of the drugs that have contributed to this statistic was cholecalciferol, also known as vitamin D3. According to data released by the Brazilian Federal Pharmacy Council, the sale of vitamin D grew by about 35% in the first months of 2020, compared with 2019. 4 One of the reasons for this increase is that some reports correlating use of cholecalciferol with an improvement in the immune response and reduced risk of respiratory tract infections have been published. 5-9 However, it needs to be emphasized that these associations have so far only been reported in observational studies and have not been confirmed through controlled clinical studies. 10 The role of vitamin D in promoting bone health is now well established. Nonetheless, the amounts of supplemental vitamin D to be use remain a subject of constant debate in the 21 st century. 11 However, use of cholecalciferol to treat a disease as recent as COVID-19, which is not supported by randomized clinical studies, inevitably falls into the category of irrational use. Irrational use of medicines is a matter of general concern for healthcare professionals, institutions and authorities.