There are to many potential confounding variables to make any causative statement based on Vitamin D levels.
Vitamin D levels increases with sun exposure. Healthy active people get more sun exposure. Just based on this relationship, Vitamin D levels should be statistically associated with heart disease, BMI, cancer, and blood pressure without any any way being causative.
Stats can be very deceiving.
I am glad that there is more research being done. Until there are some good studies and rigorous statistical analysis, there is not enough evidence to recommend vitamin D for the prevention or treatment of the flu.
This is precisely why the letter from ——a Wisconsin center for developmentally disabled ——was intriguing,
“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.
Sincerely,
Norris Glick, MD
Central Wisconsin Center
Madison, WI
And the Vit D council Dr's comments....
This is the first hard data that I am aware of concerning H1N1 and vitamin D. It appears vitamin D is incredibly protective against H1N1. Dr. Carlos Carmago at Mass General ran the numbers in an email to me. Even if one excludes 43 staff members who called in sick with influenza, 0.73% of residents were affected, as compared to 7.5% of staff. This 10-fold difference was statistically significant (P<0.001). That is, the chance that this was a chance occurrence is one less than one in a thousand.