Since bicycling occurs outside, I think many of you will find this article interesting.
https://www.outsideonline.com/2380751/sunscreen-sun-exposure-skin-cancer-science?utm_medium=social&utm_source=twitter&utm_campaign=tweet
An excerpt:
Australia’s official advice? When the UV index is below 3 (which is true for most of the continental U.S. in the winter), “Sun protection is not recommended
unless near snow or other reflective surfaces. To support vitamin D production, spend some time outdoors in the middle of the day with some skin uncovered.” Even in high summer, Australia recommends a few minutes of sun a day.
New Zealand signed on to similar recommendations, and the British Association of Dermatologists went even further in a statement, directly contradicting the position of its American counterpart:
“Enjoying the sun safely, while taking care not to burn, can help to provide the benefits of vitamin D without unduly raising the risk of skin cancer.”
Leffell, the Yale dermatologist, recommends what he calls a “sensible” approach. “I have always advised my patients that they don’t need to crawl under a rock but should use common sense
and be conscious of cumulative sun exposure and sunburns in particular,” he told me.