Thumb your nose at swine flu 29. April 2009 William Davis (35) Judging from what we know about vitamin D, it is highly probable that it confers substantial protection from viral infections, including swine flu. Dr. John Cannell of the Vitamin D Council (www.vitamindcouncil.com) first connected the dots, identifying the possibility of an influence of vitamin D on incidence of flu.In 2006, Dr. Cannell reports noticing that the patients in his psychiatric ward in northern California were completely spared from the influenza epidemic of that year, while plenty of patients in adjacent wards were coming down with flu. Dr. Cannell proposed that the apparent immunity to flu in his patients may have been due to the modest dose of 2000 units vitamin D per day he had prescribed that the patients in other wards had not been given. (Since the hospital was run by the state of California, Dr. Cannell apparently had only so much leeway with vitamin D dosing.) While it’s not proof, it’s nonetheless a fascinating and compelling observation. A similar conclusion was reached in a recent analysis of the National Health and Nutrition Examination Survey demonstrating that the higher the vitamin D blood level, the less likely respiratory infections were. Personally, I used to suffer through 2 or 3 episodes of a runny nose, sore throat, hacking cough, fevers and feeling crumby every winter. Over the last 3 years since I’ve supplemented vitamin D, I haven’t been sick even once. The past two years I didn’t bother with the flu vaccine, since I suspected that my immunity had been heightened: no flu either winter. And so it has been with the majority of my patients. Since I began having patients supplement vitamin D to achieve normal blood levels (we aim for 60-70 ng/ml), viral and bacterial infections have become rare. New research is uncovering myriad new ways that vitamin D enhances natural immune responses to numerous infections, including tuberculosis, bacteria such as those causing periodontal disease and lung infections, and viruses like the influenza virus. Enhanced immunity against cancer is also an intensive area of research on vitamin D. Will vitamin D supplementation sufficient to achieve desirable blood levels confer sufficient immunity to swine flu should it come to your door? From what we know and what we’ve seen in the few years of vitamin D experience, I think it will in the majority. But I do believe that we should still heed public health warnings to avoid contact with others, minimize exposure to crowds, avoid travel to affected areas, etc.