Saturday, October 17, 2009

Sunshine Superman

A post on the Freakonomics blog links two of Dr. Beilenson's favorite health issues together: the seasonal flu and sunlight/tanning beds. A lack of sunlight in the winter months leads to less vitamin D in our bodies which may make us more susceptible to the seasonal flu. I can't vouch for the science behind this, but it seems plausible. This is just more evidence that the proposed ban on minors using tanning beds by our county Health Department is not a good policy. It's best to let minors and parents decide what is best given the risks and benefits.

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.