Whenever I talk about sunscreen in winter, I’m invariably scolded by someone about our need for vitamin D. And I do understand it. In Britain, we’re almost all of us deficient in vitamin D during the colder months (many of us in summer, too). Low vitamin D has been linked to myriad health complaints, from mild to life-threatening. But while it sounds commonsensical, skipping sun protection to increase your vitamin D level is highly risky, and has had limited success and fallen flat under scrutiny so far.
There are far safer ways to obtain vitamin D (from supplements or, better still, a balanced diet) than by subjecting skin cells to UVA radiation, which makes up about 95% of the UV rays that reach our skin, and doesn’t even cause vitamin D synthesis. What UVA does do is destroy collagen; cause sun damage, uneven pigmentation and slackening; and play a role in some cancers. UVB, on the other hand, does help produce vitamin D, but it also burns skin, causes cancers and makes up only 5% of our exposure anyway. To chase UV rays in order to top up vitamin D levels is as sensible as swigging gin to obtain vital fluids.
