Young and healthy people have a near 100% recovery rate from Covid-19 without any medical intervention. Therefore, these very low-risk patients do not need a Covid-19 vaccine. Anyone who had the Covid-19 infection, and now has IgG antibodies does not need the vaccine. High risk individuals such as the elderly and/or chronically ill patients, and those with very high viral load exposure may benefit from the vaccine. This is a risk versus benefit analysis that should be made on a case by case basis with the patient's physician.
Vitamin D is important to the general health of a person regardless of Covid-19. With that said, high-normal levels of Vitamin D have shown improved survival from Covid-19 infection. It is advisable to have Vitamin D levels of 50 to 70 ng/mL in order to optimize the function of the immune system. My preferred method of Vitamin D supplementation is the prescription strength Vitamin D3 50000 iu once a week. Another acceptable approach is daily Vitamin D3 5000 iu which is available over the counter. It is important to periodically check Vitamin D 25-OH levels to prevent overdosage.
I recommend elemental Zinc 25mg for prophylaxis, and elemental Zinc 50mg for treatment of Covid-19. Elemental Zinc doesn't exist in pill form, therefore you need to buy Zinc as a compound. It doesn't matter which Zinc you buy as along as you get the correct dose of elemental Zinc. The only caveat is that a person may be sensitive to one formulation and not to another. Therefore, if you get nauseous from one type of Zinc then switch to another to see if you can tolerate it better.