A major Swedish study of 30,000 women recently came up with a surprising result: Swedish women who sunbathed daily during the summer had a lower mortality rate than those who were careful to avoid the sun as much as possible. This wasn’t a small effect, either: mortality was fully twice as high in the group who avoided sunlight compared to those who spent more time outdoors.
While this conclusion may be confusing at first glance, researchers suspect that a familiar dietary nutrient may be at play. Exposure to sunlight helps the human body produce vitamin D, and vitamin D deficiency can lead to a host of health problems: rickets, asthma, and cardiovascular disease.
Another problem with not getting enough vitamin D is that it may play a role in preventing certain types of cancer – or at least lowering the risk for them. This means those who completely avoid the sun may be putting themselves at risk for some serious health problems down the line.
But don’t run out to the store to buy a bottle of baby oil to go out and fry on the next sunny summer day: too much sun exposure is linked to melanoma, and other formers of skin cancer. It appears that the answer to how much sun exposure is necessary, as in so many questions of health, appears to be “a moderate amount”: be sure to get at least brief sun exposure on a regular basis (your body can continue to make vitamin D for a long time even after just a few minutes in the sun), but don’t stay out all day, as the ultraviolet radiation contained in sunlight has serious damaging effects on DNA. As one scientist who reviewed the study commented, “The findings support the consensus that the ideal amount of sun exposure for Northern Europeans is ‘a little’, rather than zero.”
Those who live close to the poles, where the intensity of the sun is much lower than it is near the equator, and those who have darker skin, may need extra sun exposure in order to make enough vitamin D: weak sunlight doesn’t provide your body with powerful vitamin D production as strong, direct sunlight does; and melanin acts to screen out some of those ultraviolet rays, which means more sunlight is needed to allow the same amount of vitamin D production as occurs in light-skinned people.
For those for whom sun exposure isn’t possible because of a health condition or a work schedule, dietary vitamin D is also an option. Fish, eggs (particularly the yolk), and beef liver are good dietary sources for those who eat meat; for vegans and vegetarians, mushrooms should be on the menu, or some supplemental tablets or pills.