The following website and video provides very useful information to help determine if Vitamin D can be produced from sun exposure based on your geographic location and the sun's angle.
The website is http://aa.usno.navy.mil/data/docs/AltAz.php and in the table the altitude needs to be about 50 degrees.
There's a website I use to know if I'm getting enough vit-D. It tells you how long you need to be in the Sun every second day for 1000IU of vit-D, exposing face and arms. I did some calculations myself and I estimated that the number it gives is the time I need to take the Sun every day in swimsuit/underwear to get 5000IU of vit-D. Here's the link, hope it's helpful:
Oh just to clarify. For current UTC time check this website right under the big city list:
In the vit-D website you need to put the time in 24h format otherwise you'll get very strange results! So for example, write 14.33 for 2:20pm if that makes sense.
Pau, this is super! I used this website to find the coordinates and elevation: http://www.zonums.com/gmaps/maptool.php
Awesome Nate, thanks! But how can you find the elevation? Looking at the terrain map all I can tell is that it's between 300 and 400 meters which isn't very accurate. Is there a better way?
Look in the drop-down menu on the top left that says "- Get/Tool >>" and change the value to "Elevation (meters)".
Awesome tool, thanks :)
Mine was even stranger. I got 0:4. What does that mean???? Do I stay 4 minutes in the sun, or is that 40? I am confused!
The output value is expressed in hours:minutes. So you need 4 minutes exposure:
(I was also able to fiddle with the values of the form and obtain a reading of 0:40 to further confirm this.)
That is what I thought. Thanks!!!
Perfect! Thank you, Nate!
I have been wondering for so long.
This is awesome. Thanks, Nate!
HW, do you mean something like tan through clothing?