For years, we’ve dutifully obeyed doctors’ orders to stay out of the sun. We’ve lived almost like vampires, venturing outdoors only in the early morning or evening hours to avoid dangerous rays. When sunlight couldn’t be avoided, we’ve slathered our skin with sunscreen — the higher the sun protection factor, the better.

Doctors say efforts to reduce our risk of skin cancer are well worth it.

However, there is a not-so-little problem. The human body needs vitamin D, which it produces when skin is exposed to sunlight.

http://www.standard.net/topics/features/2010/03/22/insufficient-d