A new six-year study of 5,065 older adults links routine vitamin D supplements to slightly faster cognitive decline — but only in people who already had enough vitamin D. What it shows, what it doesn't, and why vitamin D made in your skin is not the same as a capsule.
Read more →Most people don't get enough sun to produce adequate vitamin D, and the reasons go deeper than "we stay indoors too much." 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.
Read more →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. Here's how it works and how dminder calculates it.
Read more →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 — here's why that matters.
Read more →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. Here's how the math works.
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