A related article that was on here recently- https://www.outsideonline.com/2380751/sunscreen-sun-exposure-skin-cancer-science https://www.outsideonline.com/238

A related article that was on here recently- https://www.outsideonline.com/2380751/sunscreen-sun-exposure-skin-cancer-science https://www.outsideonline.com/2380751/sunscreen-sun-exposure... Vitamin D is something we can measure and often serves as an indicator, but large scale tests have shown limited effectiveness of supplements at resolving the issues a Vitamin D deficiency causes. e.g. We increase blood Vitamin D, but there are unknown correlative mechanisms that we aren't substituting.