In this cohort study including 683 patients with RA, those with serum folate levels between 4.3 and 8.2 ng/mL and greater than 8.2 ng/mL had 48% and 56% lower cardiovascular mortality risk, respectively, compared with patients who had serum folate levels less than 4.3 ng/mL after adjusting for demographic characteristics, body mass index, C-reactive protein level, smoking, RA medication use, and comorbid conditions. Here, CRP is linked to rheumatoid arthritis.