Is there any L-sugar that mammals have the ability to digest?

Question

I noticed there is, for example, an L-fructose, D-fructose, l-fructose, and d-fructose and that the capital prefixes and lowercase prefixes mean different things

Answer 1

L and l stand for left or LEVO
D and d stand for right or DEXTRO.

Mammals tend to consume D forms more than L forms.