Rheumatoid arthritis: is serum vitamin B12 high in active disease?

Seven clinical and laboratory indices of disease activity were compared with serum vitamin B12 levels in 32 patients with rheumatoid arthritis treated with penicillamine (16 patients) or sulphasalazine (16 patients) for up to 24 weeks. Prior to treatment each patient had active disease but a normal or low serum vitamin B12 concentration. During treatment, significant improvements occurred in all clinical and laboratory measurements but vitamin B12 levels were unchanged. We have been unable to confirm a reported positive association between rheumatoid disease activity and serum B12 concentration.