The Relationship Between Serum Vitamin D Level and Systemic Lupus Erythematosus Activity

Systemic lupus erythematosus (SLE) is an autoimmune disease which involvesvarious organs. Vitamin D is an essential ingredient in regulating the immune system. This study aimedto investigate the relationship between vitamin D and the severity of lupus activity.

This case-control study was carried out on 38 patients with lupus on the basisof the American College of Rheumatology (ACR) criteria and 44 healthy subjects with no history ofrheumatologic disease. To measure the level of 25-hydroxy vitamin D, venous blood samples (5 cc)were taken from each participant and the activity of the lupus disease was measured by the SystemicLupus Erythematosus Disease Activity Index (SLEDAI) scale. Finally, the chi-square test, independentsample t test, one-way ANOVA, and multiple linear regression analysis were used to measuremultivariate effects. The level of significance was set to be P < 0.05.

Thirty-five lupus patients and 40 healthy subjects were females (P = 0.847). Vitamin Ddeficiency was observed in the case (42.1%) and control (11.4%) groups. The mean value of serumvitamin D3 level was 35.3 ng/mL in the control group, as well as 24.6 ng/mL and 21.3 ng/mL inpatients with mild and severe SLE, respectively (P = 0.024).

In this study, high levels of 25-hydroxy vitamin D were observed among the healthysubjects compared to patients with SLE. Eventually, the level of vitamin D significantly decreased byincreasing the severity of SLE activity.