CRP and rheumatoid arthritis: In addition, the serum zinc concentrations increased in 64 of 81 RA patients who had baseline serum zinc concentrations less than 70 μg/dL before receiving polaprezinc, a drug containing zinc for the treatment of gastric ulcers, for 6 months or longer; moreover, the C-reactive protein (CRP) levels and disease activity scores in 28 joints (DAS28) in these patients significantly improved, suggesting an impact on disease activity in RA [18].