The Effect of Vitamin D Supplementation on Inflammatory and Hemostatic Markers and Disease Activity in Patients with Systemic Lupus Erythematosus: A Randomized Placebo-controlled Trial

Abstract

Systemic lupus erythematosus (SLE) is a chronic multisystem inflammatory autoimmune disease. Vitamin D has potent immunomodulatory properties that support its use in the treatment of autoimmune conditions, including SLE. We assessed vitamin D status in patients with SLE and determined alterations in inflammatory and hemostatic markers and disease activity before and after vitamin D supplementation. Patients with SLE (n = 267) were randomized 2:1 to receive either oral cholecalciferol 2000 IU/day or placebo for 12 months. Outcome measures included assessment of alterations in levels of proinflammatory cytokines and hemostatic markers, and improvement in disease activity before and after 12 months of supplementation. Disease activity was measured by the SLE Disease Activity Index. Vitamin D levels were measured by Liaison immunoassay (normal 30-100 ng/ml). Serum levels between 10 and 30 ng/ml were classified as vitamin D insufficiency and levels < 10 ng/ml as vitamin D deficiency. The mean 25(OH)D level at baseline was 19.8 ng/ml in patients compared to 28.7 ng/ml in controls. The overall prevalence of suboptimal and deficient 25(OH)D serum levels among patients with SLE at baseline was 69% and 39%, respectively. Lower 25(OH)D levels correlated significantly with higher SLE disease activity. At 12 months of therapy, there was a significant improvement in levels of inflammatory and hemostatic markers as well as disease activity in the treatment group compared to the placebo group. Vitamin D supplementation in patients with SLE is recommended because increased vitamin D levels seem to ameliorate inflammatory and hemostatic markers and show a tendency toward subsequent clinical improvement. Clinical Trial Registry NCT01425775.