According to a recent study, vitamin D supplementation could be considered as an immunomodulatory agent for systemic lupus erythematosus (SLE). SLE is a debilitating autoimmune disease characterized not only by skin, joint, neurological and renal symptoms, but also by inflammation of tissue linings in the body.
SLE is a T- and B-cell-dependent disease that causes an appearance of autoantibodies, causing the body to attack itself. Patients present with a depletion of regulatory T cells (Tregs) that normally protect against autoimmune disease, an increase in cytokine-producing T helper (Th) 17 cells and an increase in IFN-inducible genes, which trigger the body's protective responses. Recent studies have shown that vitamin D could ameliorate these effects.
In a prospective clinical trial, Nathalie Costedoat-Chalumeau and colleagues set out to evaluate the safety and immunological effects of vitamin D supplementation in 20 SLE patients with low vitamin D levels. They observed these patients over six months and found that vitamin D was not only well-tolerated but, more importantly, there were no SLE flare-ups during the follow-up period.
Although preliminary in nature, these findings suggest that vitamin D provides beneficial immunological effects for SLE, with a decrease in B memory cells and effector T cells, and an increase in Tregs. Costedoat-Chalumeau said "This should be confirmed in larger randomized controlled trials."
Costedoat-Chalumeau believes that the findings confirm that vitamin D may also play other roles in the immune system. She said "The study has highlighted interesting pathways to explore. Among the identified signatures, we observed the down-regulation of RNA polymerase functions and histone expression and the up-regulation of the TP53/CDKN1A-related pathway. These deserve further research owing to their possible involvement with a decrease in the accumulation of autoantigens and the activation and proliferation of autoreactive T and B lymphocytes."