With so much conflicting information about sunscreen, SPF and Vitamin D (oh my!), it's really difficult to sort out what's right for you. Should you wear a high SPF sunscreen every time you step outside? Are high SPFs just a marketing ploy? Or you should actually spend time outside without sunscreen because you're lacking Vitamin D? Will that give you skin cancer?

To clear things up, I talked to Dr. Leslie Baumann, who is both a professor and the director of cosmetic dermatology at the University of Miami (you can get some great information from her at The Skin Guru), and she had plenty to say about all of these questions.

I recently read that marathon runners are at greater risk for skin cancer because, for one, they're outside more often, and even if they always wear sunscreen, they're sweating and don't generally reapply as often as they should. Baumann said the trick to staying safe and sporty in the sun is to reapply every hour or after swimming. "They should pat the sweat away, not rub with a towel -- rubbing removes SPF."

And, speaking of SPF, she said, "Higher SPF is better. It is not a marketing ploy. The issue is that, in order to get the SPF on the label, you must apply a lot of sunscreen -- exactly 2 milligrams per cubic centimeter is needed, and the correct amount for your face is half a teaspoon. Most people only apply one-fourth of what they should. So, if you apply an SPF 60 the way most people do, you're really getting closer to an SPF 15. However, even if you apply it properly, there isn't a huge difference between the SPF 15 and SPF 60." That's because SPF 15 offers about a 93 percent protection from UV rays, while a rating of 60 offers more like 97 or 98 percent, so it is not actually double the coverage.

She agreed that the Vitamin D issue was important, saying, "I recommend getting your Vitamin D levels checked with a blood test. It's about $120 and insurance might cover it." Your race could play a part in Vitamin D deficiency, too, with African-Americans being at a higher risk than the rest of the population. Baumann went on to say, "If you are deficient, add Vitamin D supplements, drink Vitamin D fortified milk and eat mushrooms. If your levels don't improve, then try to get 15 minutes a day of sun without sunscreen on." However, keep in mind that this exposure can damage skin, so it's better to try the other modalities first!