http://www.freerepublic.com/focus/f-chat/1929828/posts
"In April 2005, a virulent strain of influenza hit a maximum-security forensic psychiatric hospital for men that's midway between San Francisco and Los Angeles. John J. Cannell, a psychiatrist there, observed with increasing curiosity as one infected ward after another was quarantined to limit the outbreak. Although 10 percent of the facility's 1,200 patients ultimately developed the flu's fever and debilitating muscle aches, none did in the ward that he supervised. "
(snip)
"Immediately, 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. "
I take 5,000IU of vitamin D daily.