Sun Deficiency
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Q:
Does climbing indoors or in the shade make us susceptible to osteomalacia due to vitamin D deficiency?
— Pat via rockandice.com
A:
Given our vampire-like heliophobia in recent decades, vitamin-D deficiency is a fashionable topic in medical research. To nobody’s surprise, people who shun the sun may not get enough vitamin D. But, much of the chatter has more to do with the economics of your health than your actual health. The supplement industry would rather you buy one of their concoctions than actually do something. Here’s an idea: Instead of popping a pill, catch a few rays of sunlight—along with your daily dose of cutaneous vitamin D synthesis you may even feel a little happier.
True, climbers have been conditioned to avoid the sun, albeit for purposes of friction rather than cancer (the risk of cancer lacks immediacy until the point of diagnosis and as such is a low priority to most). However, by the very nature of going climbing you are likely to catch therapeutic rays as opposed to the office worker who spends much of her day under refrigerator-style-lighting.
Osteomalacia, a condition that results in softening of the bones such that they tend to bend over time, can be caused by vitamin D deficiency. However, unless you spend your winters in Norway and your summers on the dark side of the moon, your vitamin D levels are unlikely to get that low.
Recommended levels of sunlight per day for the purpose of vitamin D synthesis vary from five to 20 minutes depending on, among other factors, how much skin is exposed, sunscreen application (above SPF 8 prevents vitamin D synthesis), time of the day, and the season.
Feature image by Simon Carter
This article appeared in Rock and Ice 231