How much sunlight do you need per day to make vitamin D?

Currently it is pretty hot in some parts of the usa, so i found a nice infographic about sunlight and vitamin D.

I usually use Vichy products to protect my skin. Vichy is a big brand in the skincare industry and protects my skin in a good way. Here below you can see some nice information about the sun and Vitamin D. 

Vichy producten