The single vitamin secret to cutting your risk of colds, flu, and pneumonia in HALF

Plus, my simple, inexpensive two-step plan for staying healthy all winter long

Just in time for cold and flu season, a major new global study found that a single, simple vitamin may be the key to fighting off all sorts of viral infections.

And it should come as no surprise to longtime readers of Insiders’ Cures which nutrient boasts these powerful antiviral benefits. I’m referring, of course, to vitamin D.

In fact, researchers found that for people with low levels of D in their blood, taking the vitamin on a regular basis cuts the chances of getting colds, flu, and other dangerous viral infections like pneumonia in half.

And even for people with higher blood levels of the nutrient, daily vitamin D supplementation reduces colds, flu, and other viral infections by 10 percent.

So how does D do this? Well, it has to do with the way your body naturally fights colds and flu.

Two simple ways to stay healthy during cold and flu season

The key to preventing viral infections is to practice good hygiene. Viruses are spread primarily by touching contaminated surfaces with your hands, and then touching your face.

And if you do get a cold, flu, or other viral infection, the key to reducing their duration and severity is to support your immune system.

One of the best ways to boost your immunity is through basic vitamin and mineral supplements. And, of course, that includes vitamin D. But the researchers behind the study I just mentioned found another reason why the “sunshine vitamin” may help fight colds and flu. More about this important discovery in a moment.

But first, let’s look at the role of hygiene and immunity in cold and flu prevention.

Why you should always wash your hands…and other hygiene tips

Practicing good hygiene goes a long way toward preventing viral infections. I recommend you do the following to help keep yourself healthy during cold and flu season… and every other season.

  • Avoid crowded spaces when possible. When that’s not an option, at least try to limit the amount of time you spend in crowds (Thomas Jefferson advised this over 200 years ago—and it remains good advice to this day.)
  • Carry hand sanitizer (alcohol-based only) and use it when you can’t wash your hands with soap and water.
  • Carry your own pen and use it at banks, post offices, and retail stores.
  • Wipe down the handles on your grocery cart.
  • After pumping gas, wash or sanitize your hands immediately, before touching anything—especially your face.
  • In a public bathroom, skip the “energy-efficient” hand dryers, and use a paper towel, or carry your own handkerchief. As I wrote in the February 2015 issue of Insiders’ Cures (“The shocking source spreading cold and flu viruses”), research shows that hand dryers just blow viruses around the whole bathroom.
  • Use a paper towel or handkerchief to open the bathroom door upon exiting.

Above all, don’t take anything for granted about public hygiene.

I recently had a shocking experience that reinforced this point. I was visiting the little town where I grew up near Boston, on the road to Lexington and Concord, which is now a “high-end” suburb of the big city.

When I was a child, there were two choices in town for Italian food. One was Bellino’s, a pizza parlor on the other side of the tracks—owned by the parents of Joe Bellino, a Heisman trophy winner from the U.S. Naval Academy. The other was called Simeone’s White Spot, located in a strip shopping mall at a five-way intersection on the outskirts of town. (I always wondered about the name “white spot,” because the only spots we ever got there were red splotches on our shirts from the tomato sauce.)

Today, there are two multiple-star Italian ristorantes—one, called La Tavola, features classic rustic fare, including wild game. The other, Lucia’s, serves classic dishes from the provincial regions of middle Italy. Neither restaurant is inexpensive.

We were at Lucia’s on a beautiful, early-fall Saturday night. While I was washing my hands in the restroom, I heard some distinctive sounds coming from a stall. The stall door opened, and I promptly stepped aside to make room at the sink.

But the satisfied customer (about 12 years old, wearing some kind of swim shorts and sports top—this at a Saturday night five-star dinner), sauntered straight out the door and back to his table to resume his fine-dining experience with his family.

I used the paper towel to get myself out the door, and went back to my table—where I had to have an extra glass of wine to recover from what I’d just seen. The food was very authentic, but this particular experience was a little more “verismo” than I could handle.

I can tell you that the parents and children at modest Bellino’s or Simeone’s in the 1960s would have known to wash their hands without having to post it (in three or four different languages) in the restrooms!

Why supporting your immune system fights flu—and vaccines don’t

In addition to practicing good hygiene, supporting your immune system is the other half of the cold and flu equation. Your immune system knows exactly how to target and eliminate each and every strain of each and every virus on the planet.

Your immune system also works against bacteria, as antibiotics do. But, unlike antibiotics, you don’t have to worry about what kind of microbe you have and which antibiotic will treat it. Your immune system naturally knows which bacteria to target.

In fact, even when you get the right antibiotic for the right bacterial infection, for the “right amount of time” (which is typically too long), your immune system still has to fight off the infection. The antibiotic just gives your immune system time to get “caught up” so that it can finish the job.

Since antibiotics don’t work for flu viruses, the mainstream tries to shoot you with vaccines. But one of the major problems with vaccines (even when they actually work) is that you need a different vaccine for every different strain of every different virus.

Of course, that’s just fine with the crony-capitalist medical system, which grows their profit by making more and more vaccines. That’s why they say you “need” a new shot of the influenza vaccine each year.

It’s true that the amazing ecology of influenza means that new strains arise every year from China through the interaction of poultry, swine, and human populations, and then spread around the world. But these viruses are cleverer than the CDC, which runs to catch up every year, trying to figure which new strains of the virus are going to be the population’s next villain. As I have described before, the CDC’s “scientific” process looks to me more like the three witches’ brew-concocting contrivancies in Shakespeare’s Macbeth.

Even worse is that the annual flu vaccines usually don’t even work. And they haven’t been shown to benefit older Americans, who the CDC insist should get these shots (as I wrote in a January 2015 Daily Dispatch, titled “Flu vaccine fails again….” You can access this by searching the article title at I’ve also written about reports of terrible reactions to the flu vaccine from European countries—whose medical statistics are quite reliable. Oddly, we don’t hear much about side effects in the U.S.. (Whether that means there are fewer incidence of adverse events here, or that such reports are kept quiet is a topic for another day.)

Instead, I suggest natural, reliable remedies.

When you are coming down with a cold or flu, take immune-system supporters like Echinacea, elderberry, honey, ginger, and lemon. I am not impressed with the available scientific data on “dosages,” so I recommend considering these ingredients more like foods. Infuse or add them, according to taste, to hot water and drink during the day as a beverage.

And, as I mentioned earlier, get plenty of vitamins and minerals. Which leads me back to the new study on vitamin D.

A one-time dose of D won’t cut it 

This study, which was published in the British Medical Journal, analyzed data from 25 clinical trials involving vitamin D and upper respiratory infections like colds, flu, bronchitis, and pneumonia. These trials included over 11,000 people from 14 different countries.1

The researchers discovered that studies, which previously found vitamin D to be ineffective in treating colds or flu only involved people who had been given a single dose of D, rather than regular daily supplements (as I always recommend).

But other studies showed a significant benefit for everyone who took vitamin D daily, or even weekly, and even more substantial benefits for those who began any given trial with low blood levels of vitamin D.

Among those with the lowest D levels (less than 25 nanomoles per liter), taking regular supplements cut the rate of respiratory infections like flu, bronchitis, and pneumonia in half. But even among those with the highest vitamin D levels, supplements reduced infections by 10 percent.

The researchers noted that previous studies had investigated whether the increase in colds and flu during winter is due to lack of sunlight and vitamin D. The conclusion was that colds and flu were more often due to people being cooped up together during the winter—which goes back to my (and Thomas Jefferson’s) advice to avoid crowds.

But lack of sunshine and vitamin D certainly doesn’t help the annual epidemic of colds and flu.

The unnecessary debate about vitamin D supplements needs to end

The authors of this study certainly didn’t have a case of cold feet when it came to cold and flu prevention. They even recommended that foods be fortified with vitamin D, so that everyone gets this indispensable nutrient.

But just as it has with other vitamin D studies, the British Medical Journal inexplicably published an editorial in disagreement.

In a 2014 Daily Dispatch (titled, “Facts should always outweigh opinions, but they don’t”), I reported on two large research reviews published in the BMJ that showed vitamin D supplementation improved health in both children and older adults.

These studies clearly showed that people should supplement with vitamin D every day. But in the very same issue where these studies were published, the BMJ editors wrote an editorial questioning the need for vitamin D supplementation. Say what?

And now they’re at it again. The editors published an opinion piece in the same issue as the new vitamin D cold and flu study saying that “current evidence does not support the use of vitamin D supplementation to prevent disease.”2

In one fell swoop, they just summarily dismissed all the other science showing how D helps prevent everything from the common cold to cancer.

Of course, skeptics will fight the idea of food fortification and supplementation tooth and nail (both body parts which rely on vitamin D, by the way). However, even the strongest skeptics tried—and failed—to find weaknesses in the new vitamin D study.

But after reading about all of the scientifically demonstrated benefits of vitamin D here in Insiders’ Cures over the years, you’re smarter than the editors at the British Medical Journal. You know not to deny the science on this essential nutrient. And based on all the available research, the case for universal vitamin D supplementation, or food fortification, is now undeniable.

So if you want to prevent cold, flu, and viral infections, simply follow the science and take a quality vitamin D supplement. I recommend 10,000 IU of vitamin D daily. In fact, I know excellent integrative medicine physicians who recommend their patients take 20,000 IU of D per day when they feel they are coming down with a cold or flu.

Vitamin D is available in convenient liquid form that can be added to warm (not hot) beverages or infusions. You can even add it to the virus-preventing “cocktail” I mentioned above, made with Echinacea, elderberry, ginger, honey, and lemon. For added benefits, look for Vitamin D with the added marine carotenoid Astaxanthin.



1“Vitamin D supplementation to prevent acute respiratory tract infections: systematic review and meta-analysis of individual participant data.” BMJ 2017;356:i6583.

2“Do vitamin D supplements help prevent respiratory tract infections?” BMJ 2017;356:j456.