What is the Role of Supplementation With Ascorbic  Acid, Zinc, Vitamin D, or N-acetylcystein for  Prevention or Treatment of COVID-19?  

Seth R. Bauer, PharmD, Aanchal Kapoor, MD, Mary Rath, RD, LD and Suma A.  Thomas, MD, MBA  

 COVID-19 may theoretically be prevented or treated with a variety of agents designed to  complement food intake or endogenous molecules. Ascorbic acid (vitamin C), zinc, vitamin D,  and n-acetylcysteine have also been proposed as COVID-19 preventive or treatment options due  to their ability to affect immune response. There is currently no high-quality evidence to justify  the use of drugs to prevent or treat patients with coronavirus disease (COVID-19). Several agents  designed to complement food consumption or endogenous molecules, on the other hand, may  theoretically help avoid or cure the disease. 

https://www.ccjm.org/content/early/2020/06/08/ccjm.87a.ccc046.long