/Africans in Africa get more sunlight and therefore, higher percentage of vitamin D in their blood and tissue.
I think this has merit. During the early stages of the pandemic, blacks presenting with covid were found to have almost nonexistent levels of Vit D. Sadly, when this was pointed out, some activists considered it racist to even mention it.
Now that time has passed, there are articles reviewing the data from the research to date and which substantiate that blacks with covid did have lower levels. Doctors in the know have been advising patients to take a minimum of 3000 mg of D3.
This is just one example of research on this issue:
https://ncats.nih.gov/pubs/features/low-vitamin-d-levels-may-boost-covid-19-risk-in-black-people