Vitamin D bears the nickname the "sunshine vitamin" because the skin produces it from ultraviolet rays. Researchers believe slapping on sunscreen may actually contribute to far more cancer deaths than it prevents as doing so blocks this vital vitamin production.

Thus, while dermatologists and health agencies have long touted that such lotions are needed to prevent skin cancer, some scientists are now challenging that advice. Their main argument: Vitamin D is important for preventing and treating many types of cancer; studies have found it helped protect against lymphoma, as well as cancers of the:

* Prostate
* Lung
* Skin
* Colon

In fact, one Harvard professor offered such compelling evidence in a recent study -- vitamin D may prevent 30 deaths for each one caused by skin cancer -- that the American Cancer Society is now reconsidering its own sun guidelines.

Getting Enough Sunshine

Many people struggle with getting enough vitamin D. Many scientists believe 15 minutes or so a few times a week of "safe sun" (void of sunscreen) is both achievable and healthful. However, the lack of consensus on how much vitamin D is needed, along with the optimal way to get it, still remains.

Why? Because even with sunshine recommendations, the amount needed would depend on, among other factors, the:

* Season
* Skin color
* Time of day
* Location a person lives in

Researchers are concerned that people -- after hearing the health benefits of reaping sunshine -- may overdo it. Therefore, experts recommend moderation with sun exposure until more evidence is presented.