I'm not a vegetarian and I don't eat as many fruits and vegetables as I should, but I don't really take multi vitamins any more.
The general scientific consesus is that you don't need them and/or you're not getting much out of them anyway. The vast majority of any multi-vitamin you take is going to go down the toilet. If you have a medically diagnosed deficiency, then I'd take a supplement. But if you're eating 1500-2000+ calories a day and have some variety in your food, then the vitamins probably aren't doing much/anything for you.
I do own a bottle of multi-vitamins and I do take them occasionally when I haven't been eating well, haven't been sleeping enough and have been binge-drinking for days at a time, but overall I'm not convinced there's a point to taking them daily.
Just my 2-cents.