i swallow them whole. but unlike y'all who can't stand the flavor, i can't stand how it sticks to my teeth! i hate all the orange crap in my teeth--it's hard to brush out, even. then when i spit it's all gross and orange.
my vitamin levels are okay or i would go back to chewing them.
as for why to chew? there is a saying 'digestion begins in the mouth' -- certain compounds start digesting in your mouth. just how our bodeis thought it best to work, i guess. it's been too long since my nutrition class to remember more than that.