Vitamin D Status in Patients with Systemic Lupus Erythematosus in Serbia: Correlation with Disease Activity and Clinical Manifestations

BACKGROUND: Numerous studies indicate potential role of vitamin D as an important factor in the development of many autoimmune diseases including systemic lupus erythematosus (SLE). Patients with SLE are especially prone to the development of vitamin D deficiency due to the nature of their illness. AIM: The aims of our study were to determine the prevalence of vitamin D insufficiency and deficiency in patients with SLE in Serbia, to identify clinical variables associated with vitamin D status and to examine the impact of vitamin D status on disease activity and presence of specific lupus autoantibodies. MATERIAL AND METHODS: The study included 46 patients with SLE. Serum 25(OH)D concentration was measured by electrohemiluminiscent immunoassay. RESULTS: The mean serum concentration of 25(OH)D was 11.9 ± 7.3 ng/ml. The prevalence of insufficiency was 32.6%, while the prevalence of deficiency was 67.4%. There was no association between vitamin D status and photosensitivity, skin lesions, arthritis and lupus nephritis. Vitamin D status was not associated with the presence of specific autoantibodies. There was no correlation between disease activity assessed by SLEDAI scale with the concentration of 25(OH)D. Patients who used vitamin D supplements and calcium did not have a significantly higher concentration of 25(OH)D. CONCLUSION: In conclusion, vitamin D deficiency is common in patients with SLE.