I have long been a firm believer in Vitamin D. Not just because of its direct effects against viruses, a breakdown product eroding the viral coat in serum, but it opens immune pathways against pathogens, and finally acts as an ACE inhibitor against the cytokine storm.
But it is unwise to see it as an absolute. So a much better way is a “defense in depth”.
Cutting to the chase, the last deadly outbreak of H1N1 was in Ukraine. Many of their doctors refused the idea that it was influenza, because “influenza doesn’t *do* that.” But what they were seeing were the consequences of the cytokine storm.
The described the lungs of some of the deceased as being black, like they had been burned. It was the first, unequivocal evidence of the cytokine storm as a phenomenon.
The other problem was the H1N1 Spanish flu. Unlike typical flu, it wasn’t limited to the winter months, and was just as active in summer, year around for that matter. And this is worrisome.
Typically, influenza doesn’t perform well south of the US border and in the tropics. But all that heat and humidity (as well as vitamin D generating sunlight), didn’t even slow it down.
Being active in the summer months means it is not so susceptible to Vitamin D as most flu bugs are. Sunshine is why flu and colds are largely winter phenomena. I remember living up nawth, in Michigan for a time and noticed there people talking about having “summer colds.” I suspect now it is because the sun, even in the summer is at a less direct angle and.
In Viet Nam flu is a “womens’ disease.” That’s probably because women cover themselves totally when they go outdoors. Their mamas have told them since they were babies that they must never let the sun touch their skin or they will turn black and never get a husband. Men don’t have that phobia and rarely get sick.