If i use retin a (tretinoin) on my face and neck, is sunscreen enough protection?

Sunscreen : I recommend a broad-spectrum sunscreen offering protection against both uva and uvb rays.At least three active ingredients are called for.These generally include paba derivatives, salicylates, and/or cinnamates for uvb absorption; benzophenones for shorter-wavelength uva protection; and avobenzone, ecamsule, and titanium dioxide, or zinc oxide for the remaining uva spectrum.Wear protective clothing.