91色情片

I read in New Scientist that exposure to the sun in winter at latitudes higher than about 35掳 results in negligible vitamin D production (9 August 2014, p 34). For many years here in Tasmania (40掳 south) I have been exercising naked in the sun just after midday to dose up on vitamin D. But have I been wasting my time in winter?

Guy Burns, Devonport, Tasmania, Australia

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This article appeared in print under the headline 鈥淪unshine down under鈥�