Vitamin D observations during epidemics
“While working as a psychiatrist at a maximum-security hospital, John Cannell screened his patients for vitamin D and found that all had very low levels. This led him to recommend that they take 2000 IU/d of vitamin D, the US “upper limit of tolerability”. Several months later an epidemic of influenza broke out at the hospital. Cannell noticed that none of the patients on his own ward developed symptoms, yet sickness was rampant among patients on adjacent wards, despite intermingling between patients and nurses [36].”