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Is sun exposure actually good for you?

April 18, 2020 / Duncan Fisher
In small amounts, yes.

Winter is finally over in the northern hemisphere, and once again, coats and boots will shortly go back into closets, sunscreen and sandals will come out, and dermatology services like ours will roll out the usual warnings about skin cancer and sunburn.

Confusingly, doctors also counsel from time to time that a little sunshine is actually good for you, and that you should go out and run around in it, as long as you don’t overdo.

There’s much to this. One of the good things we get from sunlight is vitamin D. There isn’t vitamin D in the light, of course, but sunlight falling on our skin helps our bodies manufacture this vital ingredient in our health.

‘Vitamins’, in case you’re wondering, are those organic compounds that we need not as nutrients exactly, but as aids in processing nutrients. Vitamin D, which is actually a group of compounds, not one, helps you absorb calcium and phosphorus, so you can make strong bones. It also seems to have a role to play in other things, as diverse as heart disease and high blood pressure, diabetes, some forms of cancer, and autoimmune syndromes like arthritis. It’s absolutely vital that we have it. Vitamin D deficiency, something we don’t see much anymore, is actually quite serious.

So, what’s the deal? Do we go into the sun a little bit, and then stop, before we invite cell damage or DNA mutations? If so, what does ‘a little bit’ mean?

We wish we could say.

No, you shouldn’t let yourself burn, and you should wear your sunblock, like we’ve always said. But the exact amount of sun exposure that gets you your vitamin D and doesn’t put you in danger of skin cancer is very difficult to know. Much depends on the kind of skin you have, where you are in the world, what the weather is like overhead, and what time of day it is.

A universal guideline isn’t really possible.

What we can tell you – and this matters – is that it takes very little time for your body to get its sun-induced vitamin D production done, and that when it's done, it stops.

You don’t need to be in the sun long, in other words, to get your sunshine vitamin. By the time you’re courting a burn, it’s been way too long. And staying out in the sun won’t keep increasing your vitamin D level beyond its natural setpoint.

So your doctor will not say that you should spend all day in the sun in order to be healthy. Your doctor will say that we’re not built for 24 hours of darkness, either, and that a certain amount of daylight is necessary for our physiology to run right. (This is true not only of vitamin D production, but of other functions too. Sunlight is integral in regulating the biochemistry of our sleep cycles, for instance.) Medical consensus generally? Merely running around town and doing your normal errands is probably about the right level of daily exposure.

And here’s one more thing to know. You can get your vitamin D in what you eat. It exists in abundance in oily fish, and it’s commonly added to milk, yoghurt, butter substitutes, and cereal products. You can even pick up tablets of the stuff at your pharmacy. Just ask for cod liver oil.

So as the sun comes back for another summer, we won’t retract our burn and cancer warnings. But here is also a friendly reminder, that sunshine, in sensible amounts, is actually a very good thing.

Questions about your skin? Ask our sunny dermatologists for only $35