Spend 15 Minutes in the Sun Without Sunscreen or Two Hours in the Sun Wearing SPF 30?

Better Choice: Two hours wearing SPF 30
Though spending 15 unprotected minutes in the sun every few days will provide your necessary dose of vitamin D (a nutrient essential for metabolizing calcium, and one that half of all women are short on), it can also take its toll.

"Ultraviolet exposure leads to photo damage, which results in premature aging, wrinkles, brown spots, rough skin texture, and dilated capillaries and is also a cofactor in skin cancer," says dermatologist Laurie J. Polis, director of Soho Skin and Laser Dermatology, in New York City.

It's better to ingest vitamin D, which is found in most dairy products, fortified orange juice, and many calcium supplements and multivitamins.

But… New research suggests that small doses of sunshine without sunscreen might help prevent certain cancers — like prostate, lung, and colon. But this research is still very preliminary and controversial.