I'm not sure the same consideration applies to sunblock. The article makes the case that plants always "want" to let through the same quantity of light, but not necessarily the same proportion, while we ideally want to block 100% of UV all the time.
"Vitamin D is made when UV (more precisely, UVB rays) react with a compound (7-dehydrocholesterol) in the skin. The best rays for UV synthesis have wavelengths between 270–300 nm." [1]
[1] https://www.sciencelearn.org.nz/resources/1313-vitamin-d-and...
Ultraviolet B UV‑B 280–315
Ultraviolet C UV‑C 100–280
[1] https://en.wikipedia.org/wiki/Ultraviolet
My read is "UVB" is the popular medicine way of saying UV is needed for the body to synthesize vitamin D. It was not considered necessary to point out part of the useful spectrum is in "UVC" territory.