Recent studies have showed surprising cancer-prohibitive effects of sunlight. It is well-documented that excessive sunlight exposure increases the rate of skin cancers. But now studies show that the incidence of some other, internal cancers are reduced.
Studies have revealed cancer-prohibitive effects of vitamin D on colon and breast cancers so far. Vitamin D is available from some foods, and is also produced by a reaction of the skin to sunlight. A severe deficit of vitamin D can cause disease such as rickets. Of course, if lighter skin people benefit from sunshine, darker-skinned people need even more for the same effects.
So why is this on a nudist blog? Nudists are generally sun-lovers, getting more sunlight exposure than the average person. A nude body also gets more sunlight than someone with a conventional bathing suit. Sunbathing for the sake of getting sunlight exposure/vitamin D is therefore a little safer nude, allowing one to absorb a given quantity of sunlight, spread over a little more of the body than would be the case in a bathing suit (thereby allowing one to absorb a quantity of sunlight with less time in the sun).
Of course, take into consideration your own skin’s ability to handle the sun. A dark complected person may be fine all day in the sunshine, whereas a light-complected person may burn in minutes. Sunburn should always be avoided, so regardless of your skin tone, know your own limits.
Scientific American: A Protein Twofer That Triggers Tanning and Protects against Skin Cancer
Researchers find that a protein activated to repair DNA damage also activates tanning, which can protect against melanoma.