The beneficial role of vitamin D in systemic lupus erythematosus (SLE)

Patients with systemic lupus erythematosus (SLE) have a high prevalence of abnormal bone metabolism and vitamin D deficiency. Genetic studies have provided the opportunity to determine the specific proteins linking vitamin D to SLE pathology [i.e., major histocompatibility complex (MHC) class II molecules, the vitamin D receptor (VDR), microRNAs (miRNAs), the renin-angiotensin system (RAS), apolipoprotein E (ApoE), liver X receptor (LXR), and toll-like receptors (TLRs)]. Vitamin D also exerts protective effects against SLE through non-genomic factors, such as ultraviolet radiation (UV) exposure, matrix metalloproteinase (MMPs), heme oxygenase-1 (HO-1), the prostaglandins (PGs), cyclooxygenase-2 (COX-2), and oxidative stress. Thus, vitamin D may play a beneficial role in SLE. Moreover, the use of calcitriol or 1 alpha,25-dihydroxyvitamin D-3 is optimal for the treatment of SLE patients because this active form of the vitamin D-3 metabolite can modulate inflammatory cytokine production. However, further investigation into the effects of calcitriol with SLE is warranted.