Expert: Courtney Seligman - 10/22/2008

Question
what would happen if someone was never exposed to the sun?


Answer
This is more a biology question than an astronomy question, but having some experience with the effects of the Sun myself, I believe I can give you a good answer.

Unless they had a source of vitamin D, they would develop rickets, a softening of the bones caused by malabsorption of calcium. But nowadays, almost all milk products (and milk substitutes) contain vitamin D, and there are vitamin supplements, as well.

Other than that, I don't believe there is any known downside, whereas there are several ways in which lack of sun exposure is good. The violet and ultraviolet radiation in sunlight damages the skin, the eyes, and can alter the chemistry of the circulatory system (at least in the case of various medications, which specify that a patient taking them should stay out of the Sun). Cataracts (cloudiness of the lens of the eye) are almost always due to solar exposure, and skin cancers and aging of the skin are greatly reduced in the absence of sunlight. I remember seeing a Science News cover, many years ago, which showed photographs of a 62-year old Indian woman who'd spent her life outdoors, and a 93-year old Buddhist monk who'd hardly seen the sun since he entered the monastery. His skin looked baby-smooth, while the woman looked like she'd been dead and mummified.

Of course, if you consider a good tan a sign of good health, then the pale complexion that results from lack of sunlight might seem less than attractive, but there was a time when women with the money to hire others to do outdoor labor prized their pale complexions, while those who toiled in the fields were looked down on because of their darkened complexions (their tans, that is, not racial coloring, which is another prejudice entirely). And since tanning is an effort by the body to protect itself from the Sun's harmful effects, and a not entirely effective effort at that, people who tan often and well while young end up with leathery, old-looking skin as they age.

Courtney Seligman