I am sharing a guide written by Dr. Bret Scher and Dr. Andreas Eenfeldt, which can be read in full at Diet Doctor site - see link below
"Can you boost your immune system to fight COVID-19?
This is the question on everyone’s mind as we face a worldwide crisis. We don’t yet know how to fully prevent or manage the damage caused by COVID-19, the disease caused by a coronavirus that is new to us all.
We see online claims that we can “boost” our immune system with just about everything from Vitamin C or Vitamin D to essential oils and silver nanoparticles. But how do we know which of these recommendations, if any, really work?
That’s a tough question to answer, mainly because the immune system is not “one thing” that we can easily measure. It’s an intricate and delicate system with many different components. Helping one section might impair another, or boosting a certain section may have nothing to do with fighting viruses.
That makes knowing what to do challenging. Plus, how do we know if something that helps with another virus will help with this new coronavirus? As you can see, there is much we simply cannot know.
Finally, if you are older or have an underlying health condition (including diabetes and high blood pressure), you have an increased risk of severe symptoms, and potentially, loss of life from COVID-19. We recommend taking every precaution to avoid it.
If you’re young and otherwise healthy, your risk of complications is much lower. If you do contract the virus, you’ll probably have mild symptoms and fully recover within a couple of weeks.
However, it’s possible that you may be infected with the virus without showing any symptoms. So maintaining excellent hygiene and practicing social isolation are crucial to avoid spreading it to high-risk individuals."