There are many interesting comments on the article (above).
http://www.theglobeandmail.com/news/...1852/#comments
SKIN TONE -
Vitamin D level depends heavily on skin tone, and the people from rural Mexico tend to be darker. Hey, maybe that's why the native population are harder hit? They have darker skin and tend to live in more Northern regions, so are probably Vitamin D deprived. Hmm..
Even in regions with high amounts of sunshine such as in this study from southern Arizona those with darker skin had deficient levels of Vitamin D.
Blacks 56% deficient
Hispanics 38% deficient
Whites 23% deficient
http://www.ajcn.org/cgi/content/abstract/87/3/608
Our Native populations would likely have a degree of skin pigmentation similar to Hispanics, but given the fact most live at such high latitudes and do not drink much milk I suspect many if not all are Vitamin D deficient. It would be so easy to compare the vit D levels between those admitted to hospital with severe disease to those who have mild disease and see it this is a factor in disease outcome.
PNEUMONIA
What would interest me is what were the serum 25-hydroxyvitamin D levels of those who died after developing this influenza, what was the cause of death, and what underlying conditions might have led to the deaths. If I remember correctly, many of those who have died after developing the A/H1N1 influenza this year died of pneumonia, which is what happened in 1918-19.