This is the first of what may turn out to be two or more posts on Vitamin D today, and the focus is epidemiology. The next one will be a doozie, but this is an excellent set up.
You're best off reading that, which might require 15 minutes of your time, but here's a few excepts to wet your appetite.
In early April of 2005, after a particularly rainy spring, an influenza epidemic (epi: upon, demic: people) exploded through the maximum-security hospital for the criminally insane where I have worked for the last ten years. It was not the pandemic (pan: all, demic: people) we all fear, just an epidemic. The world is waiting and governments are preparing for the next pandemic. A severe influenza pandemic will kill many more Americans than died in the World Trade Centers, the Iraq war, the Vietnam War, and Hurricane Katrina combined, perhaps a million people in the USA alone. Such a disaster would tear the fabric of American society. Our entire country might resemble the Superdome or Bourbon Street after Hurricane Katrina.
It's only a question of when a pandemic will come, not if it will come. Influenza A pandemics come every 30 years or so, severe ones every hundred years or so. The last pandemic, the Hong Kong flu, occurred in 1968 - killing 34,000 Americans. In 1918, the Great Flu Epidemic killed more than 500,000 Americans. So many millions died in other countries, they couldn't bury the bodies. Young healthy adults, in the prime of their lives in the morning, drowning in their own inflammation by noon, grossly discolored by sunset, were dead at midnight. Their body's own broad-spectrum natural antibiotics, called antimicrobial peptides, seemed nowhere to be found. An overwhelming immune response to the influenza virus - white blood cells releasing large amounts of inflammatory agents called cytokines and chemokines into the lungs of the doomed - resulted in millions of deaths in 1918.
I had not known this. It's not the influenza that actually kills you, but your own immune system's overblown response to it. So what happened in 2005 in Cannell's ward in the hospital?
I guess our hospital was under luckier stars as only about 12% of our patients were infected and no one died. However, as the epidemic progressed, I noticed something unusual. First, the ward below mine was infected, and then the ward on my right, left, and across the hall - but no patients on my ward became ill. My patients had intermingled with patients from infected wards before the quarantines. The nurses on my unit cross-covered on infected wards. Surely, my patients were exposed to the influenza A virus. How did my patients escape infection from what some think is the most infectious of all the respiratory viruses?
My patients were no younger, no healthier, and in no obvious way different from patients on other wards. Like other wards, my patients are mostly African Americans who came from the same prisons and jails as patients on the infected wards. They were prescribed a similar assortment of powerful psychotropic medications we use throughout the hospital to reduce the symptoms of psychosis, depression, and violent mood swings and to try to prevent patients from killing themselves or attacking other patients and the nursing staff. If my patients were similar to the patients on all the adjoining wards, why didn't even one of my patients catch the flu?
A short while later, a group of scientists from UCLA published a remarkable paper in the prestigious journal, Nature. The UCLA group confirmed two other recent studies, showing that a naturally occurring steroid hormone - a hormone most of us take for granted - was, in effect, a potent antibiotic. Instead of directly killing bacteria and viruses, the steroid hormone under question increases the body's production of a remarkable class of proteins, called antimicrobial peptides. The 200 known antimicrobial peptides directly and rapidly destroy the cell walls of bacteria, fungi, and viruses, including the influenza virus, and play a key role in keeping the lungs free of infection. The steroid hormone that showed these remarkable antibiotic properties was plain old vitamin D.
All of the patients on my ward had been taking 2,000 units of vitamin D every day for several months or longer. Could that be the reason none of my patients caught the flu?
You'll have to read the article for the rest of the story, but one tidbit from an epidemiological perspective before I go.
The British researcher, Dr. R. Edgar Hope-Simpson, was the first to document the most mysterious feature of epidemic influenza, its wintertime surfeit and summertime scarcity. He theorized that an unknown "seasonal factor" was at work, a factor that might be affecting innate human immunity. Hope-Simpson was a general practitioner who became famous in the late 1960's after he discovered the cause of shingles. British authorities bestowed every prize they had on him, not only because of the importance of his discovery, but because he made the discovery on his own, without the benefit of a university appointment, and without any formal training in epidemiology (the detective branch of medicine that methodically searches for clues about the cause of disease).
After his work on shingles, Hope-Simpson spent the rest of his working life studying influenza. He concluded a "seasonal factor" was at work, something that was regularly and predictably impairing human immunity in the winter and restoring it in the summer. He discovered that communities widely separated by longitude, but which shared similar latitude, would simultaneously develop influenza. He discovered that influenza epidemics in Great Britain in the 17th and 18th century occurred simultaneously in widely separated communities, before modern transportation could possibly explain its rapid dissemination. Hope-Simpson concluded a "seasonal factor" was triggering these epidemics. Whatever it was, he was certain that the deadly "crop" of influenza that sprouts around the winter solstice was intimately involved with solar radiation. Hope-Simpson predicted that, once discovered, the "seasonal factor" would "provide the key to understanding most of the influenza problems confronting us."
Hope-Simpson had no way of knowing that vitamin D has profound effects on human immunity, no way of knowing that it increases production of broad-spectrum antimicrobial peptides, peptides that quickly destroy the influenza virus. We have only recently learned how vitamin D increases production of antimicrobial peptides while simultaneously preventing the immune system from releasing too many inflammatory cells, called chemokines and cytokines, into infected lung tissue.
Other posts on vitamin D today:
- Vitamin D Deficiency and Type 1 Diabetes
- Melanoma, Sun, and Its Synthetic Defeat (Sunscreen)
- Vitamin D Deficiency and All Cancer