Vitamin D and that Flu thing:
Jacob Schor ND FABNO
September 16, 2009
As most of you are well aware from past newsletters, I believe that there is compelling evidence to think that the seasonality of flu outbreaks can be linked to seasonal fluctuations in vitamin D status in individuals. Vitamin D levels are at their highest in late summer and early fall and at their lowest in late winter and early spring. These fluctuations correspond exactly with incidence of flu infections.
To this point we have not seen anything published in the peer reviewed literature suggesting that adequate vitamin D levels are protective against the H1N1 strain of influenza. We have assumed it will be but until there is proof, doubt remains. Thus it is with interest that I read an email from John Cannell, MD just now. Dr. Cannell forwarded and email from Norris Glick, MD who describes the experience of the Central Wisconsin Center (CWC) and extended care facility.
The CWC is home for 275 residents. There are approximately 800 staff that work at the facility caring for the residents. The vitamin D levels of the residents are tested regularly the residents receive oral supplements to maintain adequate levels. In June 2009 two residents of CWC developed influenza like illness and positive for the H1N1 flu. These were the only two residents to get sick. On the other hand when it came to the staff who were not monitored for vitamin D levels, 103 got sick. [see Dr. Glickâ€'s letter below]
Granted that this data is not published in a peer reviewed journal but it certainly makes me pay attention. Dr. Cannell maintains a website about vitamin D and sends out random newsletters. You can sign up for Dr. Cannell's newsletter at his website:
Dear Dr. Cannell:
Your recent newsletters and video about Swine flu (H1N1) prompted me to convey our recent experience with an H1N1 outbreak at Central Wisconsin Center (CWC). Unfortunately, the state epidemiologist was not interested in studying it further so I pass it on to you since I think it is noteworthy.
CWC is a long-term care facility for people with developmental disabilities, home for approx. 275 people with approx. 800 staff. Serum 25-OHD has been monitored in virtually all residents for several years and patients supplemented with vitamin D.
In June, 2009, at the time of the well-publicized Wisconsin spike in H1N1 cases, two residents developed influenza-like illness (ILI) and had positive tests for H1N1: one was a long-term resident; the other, a child, was transferred to us with what was later proven to be H1N1.
On the other hand, 60 staff members developed ILI or were documented to have H1N1: of 17 tested for ILI, eight were positive. An additional 43 staff members called in sick with ILI. (Approx. 11-12 staff developed ILI after working on the unit where the child was given care, several of whom had positive H1N1 tests.)
So, it is rather remarkable that only two residents of 275 developed ILI, one of which did not develop it here, while 103 of 800 staff members had ILI. It appears that the spread of H1N1 was not from staff-to-resident but from resident-to-staff (most obvious in the imported case) and between staff, implying that staff were susceptible and our residents protected.
Norris Glick, MD
Central Wisconsin Center
Prior Newsletters on Vitamin D and the Flu:
Vitamin D and Influenza 2006: http://denvernaturopathic.com/news/influenzaandvitD1.html
John Cannell, MD's article in Virology 2007
Swine Flu Review May 2009: