RANDOMIZED DOUBLE-BLIND CONTROLLED TRIAL TO EVALUATE EFFICACY OF VITAMIN D SUPPLEMENTATION AMONG PATIENTS WITH SYSTEMIC LUPUS ERYTHEMATOSUS

Objective/background: Patients with systemic lupus erythematosus (SLE) have a high prevalence of vitamin D deficiency. We aimed to assess the efficacy and safety of ergocalciferol combined with standard care among patients with SLE. Methods: A randomized, double-blinded, placebo-controlled study was conducted among patients with SLE (N=104). The patients were randomized to receive either a higher dosage of ergocalciferol (100,000 IU of ergocalciferol weekly for 4 weeks followed by 40,000 IU of ergocalciferol weekly for 20 weeks, group A (N=52) or placebo (group B, N=52). All patients received 800 units of cholecalciferol daily for 24 weeks. Concurrent medications were adjusted as clinically required. We compared demographics, serum 25-Hydroxy vitamin D (25(OH) D) levels, SLE disease activity index (SLEDAI-2K) and treatment variables between the two groups. The outcomes were measured at baseline, 12 and 24 weeks follow-up. These outcomes included serum 25(OH) D, SLEDAI-2K, SLE flare event defined by an increase of SLEDAI-2K between 2 visits, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), urine protein creatinine ratio (UPCR), health assessment questionnaire (HAQ), the change of dosage of immunosuppressive drugs and glucocorticoids (GCS) and ergocalciferol related toxicity. Subgroup analyses were also undertaken among patients with lupus nephritis. Continuous variables between the 2 groups were compared using student’s t-test whereas categorical groups were compared using the chi-square test. Results: Of 104 patients, only 88 patients completed the study. Baseline characteristics between the 2 groups were similar. At 24 weeks, the mean ± standard difference (SD) of serum levels of 25(OH) D in group A was significantly higher than those in group B (41.2 ± 14.4 vs. 27.2 ± 10.1, p < 0.001). No difference was observed between groups A and B with respect to SLEDAI-2K, flare event, ESR, CRP and dosage of immunosuppressive drugs. However, at 12 and 24 weeks, the number of patients who could reduce GCS dosage in group A were significantly greater than group B (at 12 weeks, 39.6 vs. 17.6%, p = 0.008; at 24 weeks, 43.4 vs. 23.5%, p = 0.013). Subgroup analysis revealed no significant improvement of UPCR in group A compared with group B. Ergocalciferol related adverse reactions in both groups were similar. Serum calcium levels did not change within and between groups of treatment. Conclusion: This study was inconclusive in demonstrating the efficacy of high dose ergocalciferol in controlling SLE disease activity. However, high dose ergocalciferol could be a safe adjunctive therapy that has a corticosteroid-sparing effect on patients with SLE.