The immunological and clinical effects of 6 months of oral alphacalcidol 0.25 mcg b.i.d. were investigated in 19 patients with psoriatic arthropathy. Ten patients (mean age 60 years) received alphacalcidol and 9 served as controls (mean age 53 years). Each of the 19 patients received methotrexate 10 mg/week with a nonsteroidal antiinflammatory drug 3 months before and during the study. The primary endpoints were measurements on various immune function tests and changes in clinical parameters such as the visual analogue scale for patients' global assessment, the Psoriasis Area and Severity Index and the Disease Activity Score (DAS28). The only significant change in clinical parameters in the active group was on the ...