Now much more discussion of important role of "vitamin" D (Sun or supplements), in covid-19. The true vitamins A & K2 support related functions, & are likely to help too. These are available from liver & other organ meats, for example. Good Zn status is needed to absorb A.

This example, out of many, came to mind https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2254644/ "vitamin A plus zinc supplementation reduces the risk of fever and clinical malaria episodes".

Vit D's action links > calcium (Ca) metabolism. Vit K2 has a role in binding Ca (into bones), activating osteocalcin & matrix gla enzymes, & has covid-relevant role in immune regulation via activating growth arrest-specific protein 6. Failure of Ca binding interferes with vit-D.

These three fat-soluble vitamins are synergistic, and good health requires a balance. Unfortunately, a high-carb high omega-6 diet interferes with many functions of this "network". The benefits of /D suppl. are likely greatly enhanced by good Zn, A, K2 status, & normal insulin

A range of experience and recent observational evidence suggests that people who score high on all these points are relatively unlikely to suffer serious harm in covid-19. Evidence I've read about is found in timelines of those whom I follow, and mine, in the last few days.