Vitamin D, steroid hormones, and autoimmunity

摘要: The endogenous serum metabolite of vitamin D (calcitriol, 1,25(OH)2 D3 ) is considered a true steroid hormone (D hormone), and like glucocorticoids (GCs) gonadal hormones, may exert several immunomodulatory activities. Serum deficiency (25(OH) D), therefore reduced availability, risk factor for chronic/inflammatory or autoimmune conditions, including infectious diseases, type 1 diabetes, multiple sclerosis, especially rheumatic diseases (ARD). In ARD in particular, regulates both innate adaptive immunity, potentiating the response (antimicrobial activity) but reducing immunity (antigen presentation, T B cell activities). Regarding possible synergism between GCs, studies show that has significant additive effects on dexamethasone-mediated inhibition human lymphocyte monocyte proliferation. Conversely, seems to play role increasing autoantibody production by cells, seasonal declines trigger flares ARD, as recently shown. Finally, reduce aromatase activity limit negative related increased peripheral estrogen metabolism (cell proliferation, overactivity).