@Jux
Great question. The red line is the numbers of world deaths occurring at a specific latitude on 22nd March (it would be interesting to see an updated plot).
The blue bar chart shows the total population at that latitude.
The significance of this is as follows:
If covid 19 affects all people in the same way no matter where they live, on average, the number of deaths would have the the same peak latitude as the population peak latitude- but it does not.
You can see clearly that the death peak is at approx 40 degrees north whilst the population peak is at approx 20 degrees north.
This means there is a bias towards people dying the further north they live - well a bias towards people living between the 40th and 50th parallel, north. London, Madrid, Lombardy and New York all lie in this region and have all come out of a long, dark, cold winter.
We all know that vitamin D levels are lowin these regions, unless diet counterbalances this - see Japan, Scandinavia, Iceland etc .
For all other info, including vit D suppression of cytokine storms, this is the study for the multiple data analysis related to this:
www.dropbox.com/s/ka7h4fbi7xdz9s9/Covid-19%20and%20Vitamin%20D%20Information.pdf