RT Journal Article SR Electronic T1 Vitamin D and lung disease JF Thorax JO Thorax FD BMJ Publishing Group Ltd and British Thoracic Society SP thoraxjnl-2012-202139 DO 10.1136/thoraxjnl-2012-202139 A1 Paul E Pfeffer A1 Catherine M Hawrylowicz YR 2012 UL http://thorax.bmj.com/content/early/2012/08/29/thoraxjnl-2012-202139.abstract AB The classic role of vitamin D in the regulation of calcium and phosphate metabolism, and its effects on bone health, are well established. More recently a critical role in immunity and respiratory health has been proposed. This arises from evidence for the capacity to generate the active metabolite, 1α,25-dihydroxyvitamin D3 (1,25(OH)D3), locally in many tissues beyond the kidney; expression of the vitamin D receptor (VDR) in immune and structural cells not involved in calcium-phosphate homeostasis; and control by 1,25(OH)D3 of the transcription of genes associated with numerous different biological processes through its nuclear VDR. Abnormalities in the vitamin D axis, including a high prevalence of vitamin D insufficiency worldwide, now appear important in a wide range of pulmonary diseases including viral and bacterial respiratory infection, asthma, chronic obstructive pulmonary disease, and cancer. Actions of vitamin D on innate immune responses, for example, production of antimicrobial peptides and autophagy, and on adaptive immune responses, for example, promoting regulatory lymphocytes, are believed to underpin these associations.