Studies suggest 4 vitamins to lower risk of severe cases of COVID-19 By Melissa Wilson Studies show vitamin supplements crucial to fighting COVID-19 Dr. Peter Osborne offers advice on how to take in the vitamins you need to help fight COVID-19. We've learned a lot the past year about how to fight COVID-19. The latest studies show an arsenal in your medicine cabinet could be quite simple, in the form of vitamins. We get all types of medical tests to evaluate everything from blood pressure to cholesterol. After dozens of studies have recently shown the importance of Vitamin D when fighting COVID-19, Dr. Peter Osborne with Origins Nutrition Center suggests, you consider a blood test to check your vitamin levels.