Just as flu season gathers force here in the northern hemisphere, it’s petering out in the southern half of the globe. No matter where you are, you’re more susceptible to the flu in the winter months. Even if, let’s say, some research physicians expose you to live flu virus in the middle of summer, you’re still less likely to get sick than if the same doctors hit you with the same virus in the dead of winter. Why? One big risk factor for flu infection is a lack of vitamin D. We naturally produce vitamin D when we’re exposed to sunlight, and as the days shorten in the winter, we produce less and less of it. That led these researchers to think that flu epidemics could be a sign of widespread vitamin D deficiency, due in part to decreased solar radiation. So it seems darkness makes the flu go ’round. (HT: Jason Tetro) [%comments]
What Makes Flu Seasonal?
TAGS: Disease
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Isn’t it due to the fact that protien coat of the flu virus deteriorates under high temperature and humidity? Hence flu transmission is lower in summer?
Is is possible that we are more vulnerable to the flu when it’s cold outside, which lowers our immune system?
I have often disbelieved the traditional answer for colds and flu, that we catch more in the winter because we are in confined spaces more.
This new answer is as good as any, but would not appear to be the final word. Why, for example, is Flu seasonal even in countries close to the equator? There was still plenty of sunlight in most of Mexico last winter when H1N1 ran rampant.
The flu virus is resistant to cold, dry environments while it’s weakened by warmth and humidity.
can you take Vitamin D over the counter to prevent catchign the flu?
Well the lack of sun light argument does not explain the epidemic in Mexico…
We are indoors more, and children are in school.
It’s always sunny and warm in Mexico so maybe N1H1 started out as stronger than average flu… And Mexico doesn’t have any schools – that’s why illiterate Mexicans have to come here to find work.