In the July 2005 FASEB Journal, Adrian F. Gombart of the University of California, Los Angeles (UCLA) and his colleagues reported that vitamin D boosts production in white blood cells of one of the antimicrobial compounds that defends the body against germs.\n\nImmediately, Cannell says, the proverbial lightbulb went on in his head: Maybe the high doses of vitamin D that he had been prescribing to virtually all the men on his ward had boosted their natural arsenal of the antimicrobial, called cathelicidin, and protected them from flu. Cannell had been administering the vitamin D because his patients, like many other people in the industrial world, had shown a deficiency:
Liu PT, Stenger S, Tang DH, Modlin RL. \nCutting Edge: Vitamin D-Mediated Human Antimicrobial Activity against Mycobacterium tuberculosis Is Dependent on the Induction of Cathelicidin.\nJ Immunol. 2007 Aug 15;179(4):2060-3.\nPMID: 17675463 [PubMed - in pr