Hello everyone.
I was curious if its ok to reuse dvc that has been used already? Is there any drawbacks?
Thanks for your help!!

This is a good FAQ topic. I'm pretty sure it's been answered before somewhere in here, but the short answer is that paying jobs are always safest going to a fresh tape. Personal jobs not involving money are fine on one-or-more-pass tapes. I've got a couple of cassettes that have been re-recorded numerous times without issue, but I'd never use one of those for business purposes. Besides, tape is the cheapest thing -- the least expensive part of the production chain -- so why bother re-using them.

I agree--I always use new tape, except for copying artwork in the studio, or maybe for freebie projects on occasion. If it's a paying job, use new stock.
However, to answer your question, there is no loss of video quality. The only problem is that the more you use a tape, the more chance you will have of getting dropouts or other tape damage.