There are a few things here.

1.)  If this is a spline object, you need to increase the surface fidelity.

2.)  If this is vertex object, you can first select all vertices and smooth all vertices as GKDantas has suggested as a first try.

3.)  If step 2 doesn't work, you can select any part of the mesh in the vertex modeler to bring up the vertex smoothing option.  Then select the level you want to smooth things out.  One hitch though is that if you do this it will change the shape of the object so this might not be what you're up for.

-Kix