Serum vitamin B12 levels of patients with rheumatoid arthritis.

To elucidate the role of vitamin B12 in the formation of anemia in patients with rheumatoid arthritis serum B12 levels were investigated in patients with rheumatoid arthritis, patients with osteoarthritis and normal subject. Serum B12 level in patients with rheumatoid arthritis was significantly higher than that in patients with osteoarthritis and normal subjects. Serum B12 level increased in proportion to Steinbrocker's stages, and was related more closely to hemoglobin concentration than to erythrocyte count and had a high correlation with alpha1- and alpha2-globulin.