Efficacy of vitamin D in patients with active rheumatoid arthritis receiving methotrexate therapy

To determine the efficacy of oral vitamin D [25(OH)D] in patients with active rheumatoid arthritis (RA) who are in methotrexate (MTX) therapy, patients receiving stable doses of MTX were randomized to one of two dose groups and received 12 weeks of double-blind vitamin D[25(OH)D] (50,000 IU per week) or matching placebo. The moderate and major efficacy measure was the proportion of patients with >0.6 and >1.2 improvement in RA based on the Disease Activity Score 28(DAS 28) at 12 weeks. Safety measures included adverse events and laboratory assessments. On a background of MTX, the percentage of patients with a moderate/major DAS 28 response at week 12 in the vitamin D groups (76/44%) was not significantly different from placebo (64.6/33.4%). Adverse events were typically mild and included small hepatic enzyme elevation; we did not have any undesirable events resulting in discontinuation of study drug. In patients with active RA receiving stable doses of MTX, vitamin D showed non-significant improvement in efficacy outcomes compared to placebo.