Paul Lambert's side have lost their last five Premier League games without scoring a goal, and Vlaar has refused to offer any excuses for how Villa have been performing.
"We have to step up. We are conceding too easily and it is hard for us to make goals, that is a team thing. It is frustrating to lose again," the Dutch defender told reporters. "We have to do better that is one thing for sure. We have start to picking up points again and results because results give confidence.
"It is easier said than done, we have to work really hard to achieve something and build on that at the moment. It is hard for us. It must be frustrating for the fans as well, I know that.
"It is always easy to talk afterwards and say what is going wrong and what was right and what the problems are but there is only one thing to do and that is step up again."
Villa return to action against Tottenham Hotspur on Sunday afternoon.