Support for Winter Tanning

The news is full of flu reports and suggestions (wash your hands). But why is the flu more likely in the winter? My first reaction was because it's cold, which actually doesn't make any sense. The real reason is a little more rational:

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.