Dial the sunscreen back a little

There's growing scientific evidence that Vitamin D--produced naturally in human beings when plenty of bright sunshine (specifically, light in the dreaded ultraviolet spectrum) hits the skin--may be a very potent preventative against many kinds of cancer, including (gasp) skin cancer.

In the last three months alone, four separate studies found [Vitamin D] helped protect against lymphoma and cancers of the prostate, lung and, ironically, the skin. The strongest evidence is for colon cancer.

Many people aren't getting enough vitamin D. It's hard to do from food and fortified milk alone, and supplements are problematic.

So the thinking is this: Even if too much sun leads to skin cancer, which is rarely deadly, too little sun may be worse.

No one is suggesting that people fry on a beach. But many scientists believe that "safe sun" — 15 minutes or so a few times a week without sunscreen — is not only possible but helpful to health.