The association with vitamin C would seem to increase the bioavailability of Quercetin, interrupting the entry, replication and enzymatic activity of the virus and at the same time supporting and strengthening the immune response. The combined administration of Quercetin and vitamin C is an experimental strategy for the prevention and treatment of different respiratory viruses.


Structural stability of SARS-CoV-2 3CLpro and identification of quercetin as an inhibitor by experimental screening
Quercetin: a flavonoid with the potential to treat asthma Quercetin Directly Interacts with Vitamin D Receptor (VDR): Structural Implication of VDR Activation by Quercetin
The effect of quercetin on the prevention or treatment of COVID-19 and other respiratory tract infections in humans: A rapid review
Effects of vitamin D and quercetin, alone and in combination, on cardiorespiratory fitness and muscle function in physically active male adults.