https://dminder.info/blog Science, tips, and updates about vitamin D and safe sun exposure. en-us https://dminder.info/blog/a-pill-is-not-the-sun https://dminder.info/blog/a-pill-is-not-the-sun Thu, 10 Sep 2026 12:00:00 -0700 A 2026 BMJ Open study of 5,065 older adults found routine vitamin D supplements were linked to slightly faster cognitive decline — only in people who were already replete. What it shows, what it doesn't, and why skin-made vitamin D is not the same as a capsule. https://dminder.info/blog/why-80-percent-are-deficient https://dminder.info/blog/why-80-percent-are-deficient Wed, 19 Mar 2026 12:00:00 -0700 Most people don't get enough sun to produce adequate vitamin D. Latitude, skin type, ozone levels, and time of day all play a role — and most people don't know when they can actually make vitamin D. https://dminder.info/blog/what-is-the-d-window https://dminder.info/blog/what-is-the-d-window Wed, 12 Mar 2026 12:00:00 -0700 The D window is the period each day when UVB rays are strong enough to trigger vitamin D production in your skin. Outside this window, you can sit in the sun all day and produce zero vitamin D. https://dminder.info/blog/ozone-and-vitamin-d https://dminder.info/blog/ozone-and-vitamin-d Wed, 05 Mar 2026 12:00:00 -0800 UV index alone doesn't tell the whole story. The ozone layer filters UVB rays before they reach your skin, and ozone levels vary by location and season. dminder uses real-time NOAA satellite ozone data. https://dminder.info/blog/skin-type-and-burn-time https://dminder.info/blog/skin-type-and-burn-time Thu, 20 Feb 2026 12:00:00 -0800 Darker skin needs more time to produce the same amount of vitamin D, but lighter skin burns faster. Understanding your Fitzpatrick skin type is the key to getting enough D without getting burned.