My decision to take/not take a multi-vitamin was based on my nutritional break-down on fitday. I say input your stuff for a while and keep an eye on where you've got low numbers- supplement based off that.
While we've got this primal community, being primal is a individual endeavour so I'd forget about the "should we be doing xyz" and just figure out what's good for you.
Because if you didn't know, of that is life made: only of moments; Don't lose the now.
~Borges