Effect of Vitamin D and Calcium Supplementation in Patients with Systemic Lupus Erythematosus

Background: Systemic lupus erythematosus is a chronic autoimmune disease that increases the risk of suboptimal vitamin D levels. Aim: To determine the effects of vitamin D and calcium supplementation on disease activity, related immune markers and bone mineral density in patients with systemic lupus erythematosus. Subjects and Methods: Eighty-one patients with systemic lupus erythematosus aged 20-70 years were recruited for this interventional study. Participants were enrolled into the following groups: no corticosteroid treatment (n = 21), corticosteroid treatment but without supplementation (n = 30) and corticosteroid treatment along with oral vitamin D and calcium supplementation (n = 30). Disease activity and laboratory parameters of all participants were measured at baseline and at 6 months. Bone mineral density was assessed using standardized dual-energy X-ray absorptiometry. Results: At baseline, none of the patients had a normal vitamin D status. There were no significant correlations between vitamin D status and the studied immune markers or disease activity values before and after supplementation. After 6 months, patients who received supplementation showed significant (P = 0.002) improvements in bone mineral density. In addition, frequency of osteopenia decreased from 40% to 16.7% and that of osteoporosis decreased from 26.7% to 13.3%. Conclusion: Vitamin D and calcium supplementation significantly improved the bone mineral density in vitamin D-deficient patients with systemic lupus erythematosus but did not significantly attenuate immune markers or disease activity. Further investigations are recommended with higher doses of vitamin D and longer durations to normalize the vitamin level and, possibly, achieve better disease control.