IFNA1 and systemic lupus erythematosus: Immunomodulatory effects of vitamin D were examined in patients with SLE and it was then shown that 1,25-(OH)2-D3 suppressed the proliferation of activated B cells, decreased the number of memory B cells, and reduced the production of immunoglobulin, which also inhibited the maturation and activation of dendritic cells and reduced the production of IFN-α.