Influenza kills an average of 36,000 people in the United States every winter. Flu vaccines are an effort to protect against this but are notoriously ineffective.
Recently the Vitamin D Council has published a paper entitled, “Epidemic Influenza and Vitamin D” by Dr. John Cannell. In this article, Dr. Cannell and his colleagues propose that Vitamin D deficiency is the reason influenza is much more common in the winter than in the summer.
Vitamin D is the only vitamin made by the human body and for that reason it is called a Pro-Hormone. We need ultraviolet B radiation (UVB) from the sun, in order to allow the skin to manufacture Vitamin D for our body. In Northern climates, including most of the United States, we just don’t get enough sunshine and therefore not enough UVB to make adequate Vitamin D in the winter. In addition, ozone (for example, smog) blocks the UVB, so even those places like Southern California that are getting plenty of sunshine, have a reduced amount of UVB in the winter.