Normally I’m not a big supplement person - I try to keep things simple & get the bulk of my vitamins from the foods I eat. During non-pandemic times (cannot even believe there is now such a delineation) I took a daily multi-vitamin and calcium with Vitamin D and that’s it.
In these strange, strange times though I have also added Vitamin C (500mg) and Zinc (50mg) to my daily dose as both help boost immunity.
In addition to vitamins, the other things I do to help keep my immune system functioning its best (now & during regular times) are: getting enough sleep, eating non-processed foods, exercising daily, soaking in the sun....and of course spending time in my infrared sauna wrap.
Luckily for most of us we haven’t had to spend much time actively thinking about our immune systems before this. If you haven’t made changes yet, it’s not too late - unfortunately we’re probably going to be dealing with this for a while. Talk to your doctor and see what makes the most sense for you.