Vitamin D & Sun Guides
Short, science-backed answers to the questions people actually ask about making vitamin D from sunlight — when the sun is strong enough, how long to stay out, and how the numbers are worked out. No fluff, sources cited.
Can I Make Vitamin D Right Now?
The answer depends on the UV index and how high the sun is — both of which change by the hour. Here's how to check in ten seconds, including a test you can do with your own shadow.
Read guide →How Much Sun Do I Need for Vitamin D?
Realistic exposure times by skin type, why midday matters, how much skin to bare, and why more sun past a point adds burn risk but no extra vitamin D.
Read guide →Vitamin D Sun Exposure Calculator: How It Works
What a sun exposure calculator actually computes — UV strength, sun angle, skin type, exposed skin and age — plus a worked example you can do by hand.
Read guide →These guides are general information, not medical advice. For the full method behind our numbers, see the science; for common questions, the FAQ.