Conclusion
DISEASE, VITAMIN D DEFICIENCY
Vitamin D deficiency is common in SLE, and the prevalence may be similar to that encountered in the community. The geographical location of residence is the primary determinant of plasma vitamin D levels rather than the disease activity. The IFN-regulated proteins galectin-9 and CXCL-10 reflect disease activity independent of vitamin D levels. High-dose oral vitamin D supplementation seems safe and more effective in improving vitamin D levels in SLE, but its role in modifying disease progress will need further studies.