To be honest, that question is really best answered by a doctor, but I'll throw couple of ideas out there. First, as long as I've had RA, my rheumatologist has done regular blood tests to keep an eye on things (e.g., it's quite common to be anemic with this disease). As well, depending on level of disease activity, for a long time I had regular x-rays, although I'm not sure if that's still the accepted practice - I guess the goal is to keep an eye not just on what can be seen in blood test, but also whether the disease is damaging your joints. The role of vitamin D in RA is a fairly newly discovered one, so I don't think it's quite become common practice yet, but I would suggest that you ashy doctor to check your vitamin D levels.

I've also had positive results from supplementing my traditional medical care with a licensed naturopathic doctor, who has assisted me with supplements, vitamins and some herbal meds that has helped improve my overall health. Of course, if you do supplement with e.g., naturopathic medicine, it's very important to make sure that you find someone who is properly trained and licensed - they will know enough about traditional Western medicine to know about interactions between medicaitons and herbal neds/supplements and which things you should stay away from (some time ago, I wrote a post on alternative medicine that you might find helpful).