There was an interesting article on Mercola that cited a study in the British Journal of Cancer that shows the correlation between vitamin D levels and prostate cancer. Men with prostate cancer were as much as seven times less likely to die if they have high levels of natural vitamin D (from sunlight).
Being that most men will develop prostate cancer in their lifetime… this is pertinent to… well, most men. Having appropriate levels of vitamin D is an important thing you can do in fighting or preventing many different cancers.
The best way to obtain vitamin D is through sunlight. By getting plenty of sunlight you can get your vitamin D without overdosing and creating vitamin D toxicity (easily done by taking too many pills).¬† If you are unable to get enough sunlight, then taking a vitamin D3 supplement makes sense… it is just hard to know your blood levels of vitamin D unless you get tested… so it is much more advisable to spend time in the sun.
And no, you do not need to worry about getting skin cancer from the sun. In fact you are more likely to get it by avoiding the sun and using toxic sunscreens on your skin. That doesn’t mean you should go outside and fry yourself candy apple red, but it does mean you should gradually increase your sun exposure till you can regularly be in the sun without worrying of getting burnt. In fact, chances of melanoma decrease with greater sun exposure.