Ferret,
I am not trying to defend a position here just attempting to protect those who seek information on this board from misinformation. The OP suggested antioxidants as a way to help prevent and treat COVID-19. It is not. As you usually are, you are correct in your assertion that most people are deficient in Mg and D3. Neither are antioxidants. Additionally, research suggests that dietary supplements are no substitute for a healthy diet. As a moderator I hope I hope I have made my point and it would be inappropriate for me to comment further.