Boost Vitamin D Intake to Avoid Infections

Dr. William Davis Health Pro
  • While the world frets over the possibility of a swine flu pandemic, is there anything you can do to further protect yourself?


    Yes: Take vitamin D.


    I say this from experience. 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 a rare thing indeed.


    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. And so it has been with most of my patients.

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    In winters and springs past, I dreaded facing patients in the office, hacking and coughing with viruses and flu, since my staff and I would often end up sharing in all the viruses. But now, patients with viral illnesses are rare. The few that do show up sick end up keeping it to themselves, since we all take supplemental vitamin D.


    Psychiatrist Dr. John Cannell of the Vitamin D Council ( first made the connection between flu and vitamin D back in 2006, when he noticed that his psychiatric ward in northern California seemed to be spared from the influenza epidemic of that year, while plenty of patients in adjacent wards were coming down with flu. The only discernible difference was that Dr. Cannell's patients all took (a modest dose of) 2000 units vitamin D per day. (Since the hospital was run by the state of California, Dr. Cannell apparently had only so much leeway with vitamin D dosing.)  


    A similar conclusion was reached in a recent analysis of the National Health and Nutrition Examination Survey, sponsored by the National Institutes of Health, demonstrating that the higher the vitamin D blood level, the less likely respiratory infections were.


    Research is discovering many news ways that vitamin D may enhance natural immune responses to numerous infections, including tuberculosis, various bacteria such as those causing periodontal disease and lung infections, and viruses like the influenza virus. Vitamin D is suspected to increase the expression of natural cellular defense substances called "defensins," molecules that exert powerful antimicrobial effects. Enhanced immunity against cancer is also an intensive area of research on vitamin D.


    I believe that emerging research, as well as anecdotal experiences such as that of Dr. Cannell and mine, suggest that vitamin D enhances immunity to viral infections enormously, including influenza. While we should still heed public health warnings should they come our way to avoid contact with others who have the swine flu, minimize exposure to crowds, avoid travel to affected areas, etc., I believe that we can further minimize the likelihood of contracting this potentially dangerous virus with vitamin D supplementation.


Published On: April 29, 2009