“…Vitamin D also enhances generation of reactive oxygen and nitrogen species in leukocytes 76 , as well as enhances epithelial barrier function and chemokine secretion, 76, 77 . Vitamin D affects corticosteroid responses, enhancing corticosteroid inhibition of RANTES secretion stimulated by TNF-alpha and suppressing corticosteroid induction of fractalkine in airway smooth muscle cells 78–80 . The adaptive immune system is also affected by vitamin D. 1,25-OH(D) is produced by macrophages, dendritic cells, T and B cells, which all express vitamin D receptor (VDR).…”