Vitamin-wise, there's occasionally a few vitamins that are handy to boost up on, at least a little. Zinc and Vitamin C in particular for a little bit of an immune system boost.

But by boost, I wouldn't say take the standard "2000%" mega pills, so much as add a little more to your diet or include an occasional vitamin supplement every once in a while.

I think most multivitamins are a bit of a crock though. Usually covering far more than is sensible or usable in a person's daily diet.