Here are some good suggestions from the ICIM for reducing risk from Covid-19.
These are their suggestions for basic supplements to support your immune system to minimize symptoms if you should catch the virus:
The following inexpensive supplemental levels are recommended for adults; for children reduce these in proportion to body weight:
1. Vitamin C: 3,000 milligrams (or more) daily, in divided doses.
2. Vitamin D3: 2,000 International Units daily. (Start with 5,000 IU/day for two weeks, then reduce to 2,000)
3. Magnesium: 400 mg daily (in citrate, malate, chelate, or chloride form)
4. Zinc: 20 mg daily
5. Selenium: 100 mcg (micrograms) daily
Please note that since this was written the CDC has updated their mask-wearing recommendations. They now recommend that everyone wear a mask in any public setting, especially when social distancing can’t be maintained.