So does anyone give their kids vitamins?

I was thinking this morning that because Zander isn't eating properly it might be the reason he's had two colds in the last month. This afternoon, I bit the bullet & bought him some multi vitamins. I never thought I'd have to, because my child would be fed properly etc, but he's just sooo fussy with food at the moment. You know, all the stuff you think before you have them

If you gave / give your kids vitamins did you notice a difference in them?