Many websites have been promoting vitamin D as a way to prevent infections by the novel H1N1 influenza virus, commonly known as swine flu, and now Canadian health authorities are going to investigate whether it works. The Toronto Globe and Mail reports that the Public Health Agency of Canada will measure the levels of vitamin D in the blood of H1N1 patients and compare the levels with those of uninfected people.
The rationale for the new look at vitamin D is based on studies in the 1940s with a different strain of swine flu that showed that mice with low levels of vitamin D in their diet were more susceptible to infection. The reason for the supposed protection is unclear, but many speculate that vitamin D bolsters the immune system.
-- Thomas H. Maugh II