My wife and I enjoyed the Covid experience back in February of 2020 before anyone knew what it was. At one month before my 74th birthday it was a hoot.
101F temperature. i couldn't taste or smell for three days. Not even the cure all hillbilly medicine from Scotland. Lasted almost a week.
Sleep,???, hardly.
As someone with years of medical training, I legally cannot say the Glenfiddich was therapeutic, but it did help. So did having O2 on hand.

I wouldn't wish this experience on anyone.

As for vitamins, I agree with 180 about the vitamins and immunity. I religiously take my supplements all the time. I did not miss my daily doses. However, I do credit them with being healthy as the reason I did survive. Apparently without harm.
For the record, vitamins and supplements are not items one takes to regain health but to keep it. They will not stave off illness but will improve your body's ability to function and react quickly to invasive pathogens. Which quite honestly is what the COVID-19 vaccine actually does.

In the true definition of a "vaccine," it is not. But it could make the difference if you are exposed.