As far as I'm aware, unless you're already B12 deficient, the B12 in 5hr Energy doesn't do much of anything because it already hangs around in your blood stream for a long, long time. Half life on B12 in the body is something like 6 days and excess is even stored in the liver instead of excreted.

Can't speak to the other ingredients but I'd guess it's all the same: either it's already available in abundance if you're eating a decent diet, or the half life is close to that of caffeine