Everything you thought you knew is wrong. This seems to be a common finding in medicine. Recent research is showing that Vitamin D is essential in preventing several kinds of cancer, including lymphoma, cancers of the prostate, lung, colon and, ironically, skin cancer. But for years dermatologists have been teaching everyone never to bare their skin without a heavy sun blocker, to block ultraviolet rays that cause skin cancer. The kicker is though, the same UV blockers prevent the body from manufacturing Vitamin D, which is produced when the skin is exposed to sunlight. So which path leads to the light?