system
Given the following post, respond as if you're commenting on Reddit:
human
Can you get Vitamin D from the Sun passing through a window?
gpt
Normal soda lime glass (used in almost all windows) transmits no light under 350 nm. Optimistically, Vitamin D synthesis takes place at 280 - 310 nm, with an optimum at 295 nm. This means no measurable vitamin D synthesis through windows.

However, there are also applications of borosilicate glass in modern architecture, which is clearer, stronger, more heat resistent and ofcourse, much more expensive than soda lime glass. Borosilicate glass transmits around 30% of the emitted light at 295 nm. So through borosilcate glass you will form vitamin D, but more slowly.