"How to Prevent the Flu"

Dr. Mercola is the founder of the world’s most visited natural health web site,Mercola.com. You can learn the hazardous side effects of OTC Remedies by getting a FREE copy of his latest special report The Dangers of Over the Counter Remedies by going to his Report Page.

By Dr. Mercola

Colds are a leading cause of doctor visits and missed days from work and school, and this season is no exception. Americans suffer from approximately 1 billion colds per year, or about two to four colds per year for the average adult.

But why do people start getting sick as the leaves start to fall?

Unfortunately in the US, thanks to the CDC, nearly anyone seeing their doctor for a cold will be told that they are infected with H1N1 and will be added to the already inflated CDC statistics.

However, according to the CBS News study, when you come down with chills, fever, cough, runny nose, malaise and all those other "flu-like" symptoms, the illness is likely caused by influenza at most, 17 percent of the time, and as little as 3 percent! The other 83 to 97 percent of the time it's caused by other viruses or bacteria.

So remember that not every illness that appears to be the flu, actually IS the flu. In fact, most of the time it's not.

Nevertheless, as temperatures drop, we begin to congregate indoors and spend less time in the sun. This means our vitamin D levels begin to drop, and we are more apt to spread viruses from one person to another.

It isn’t that these opportunistic pathogens magically appear at certain times of the year—they’re always around. It’s your ability to respond to them that changes with the seasons.

It is important to understand the causes of viral upper respiratory syndromes if you want to avoid them.

The Real Cause of Colds and Flu

Many people believe that colds and flu are caused by bacteria, but this is simply incorrect. Colds and flu are caused by viruses, and using antibiotics to treat a viral infection is inappropriate and completely ineffective.

Viruses are orders of magnitude smaller than bacteria and have entirely different structures that make antibiotics useless. (Occasionally antibiotics are required if there is a secondary bacterial sinus infection or bronchitis/pneumonia, but this is the rare exception.)

It is also important to recognize that, although a virus triggers your cold or flu symptoms, it is not the real cause of the illness.

So, what is the real cause of colds and flu?

My simple and short answer has always been that it’s due to an impaired immune system. That’s still true. However, research has confirmed that “catching” colds and flu may be a symptom of an underlying vitamin D deficiency! Less than optimal vitamin D levels will significantly impair your immune response and make you far more susceptible to contracting colds, influenza, and other respiratory infections.

Although there are many ways you might end up with a weakened immune system, the more common contributing factors are:

• Vitamin D deficiency, as previously mentioned
• Eating too much sugar and too many grains
• Not getting enough sleep
• Insufficient exercise
• Inadequately managing emotional stressors in your life
• Any combination of the above

THE Number One Way to Conquer a Cold or Flu: Vitamin D

Vitamin D is an amazingly effective antimicrobial agent, producing 200 to 300 different antimicrobial peptides in your body that kill bacteria, viruses and fungi.

In the United States, the late winter average vitamin D level is only about 15-18 ng/ml, which is considered a very serious deficiency state. It’s estimated that over 95 percent of U.S. senior citizens may be deficient, along with 85 percent of the American public.

In 2009, a team of researcher’s from Children’s Hospital Boston analyzed blood samples taken from 5,000 children under age 12 and found that nearly one out of five children in the U.S. have low blood levels of less than 50 nanomoles per liter, the level recommended by the American Academy of Pediatrics. They also found that two out of three children have a level below 75 nmol/L--which is still insufficient, based on most of the research coming out today.

No wonder colds and flu run rampant each year.

The best source for vitamin D is direct sun exposure. But for many of us, this just isn’t practical during the winter. The next best thing to sunlight is the use of a safe indoor tanning device. If neither natural nor artificial sunlight is an option, then using oral supplements is your best bet.

Remarkably, researchers have found that 2,000 IU of vitamin D per day abolished seasonal influenza. This is somewhat surprising, as it is half the dose of what most adults need to achieve ideal levels of vitamin D

Please note that this is far greater than the recommended daily allowance (RDA) advised by public health agencies like the American Academy of Pediatrics, which recently doubled the RDA of vitamin D for children to 400 IU. This new guidance still falls absurdly short of what’s needed to keep kids healthy, especially during flu season.

In order to prevent the flu, children and adults need 35 IU of vitamin D per pound of body weight. So, for example, a child weighing 57 pounds would need 2,000 IU a day of vitamin D.

Adults typically need an average of 5,000 IU per day—but some adults have to take 20,000 to 30,000 IU daily to get their vitamin D level up to optimal levels. Exactly how adults absorb and process vitamin D so differently is still somewhat of a mystery, so the only way to know if your vitamin D level is therapeutic and nontoxic is by having your blood tested.

Not all vitamin D testing is accurate, so make sure your health care provider is ordering the correct test.

Lifestyle Options: Choose Wisely

As you know, I’m not an extremist. I advocate balancing healthful choices with enjoying life, which includes celebrating from time to time.

That said, if you feel yourself coming down with a cold or flu, this is NOT the time to be eating sugar, artificial sweeteners or processed foods. Sugar is particularly damaging to your immune system--which needs to be ramped up, not suppressed, in order to combat an emerging infection.

You must address nutrition, sleep, exercise and stress issues the moment you first feel yourself getting a bug. This is when immune-enhancing strategies will be most effective.

When people come down with a cold or flu, it’s because some combination of factors has weakened their defenses. You might be able to get away with one or two transgressions, but a bucketful of poor choices will cause your immune system to crash. And then suddenly…you’re sick.

When you’re coming down with a cold, it’s time to address ALL of the contributing factors immediately.

This would be a good time to tweak your diet in favor of foods that will strengthen your immune response. Good choices include:

• Raw, grass-fed organic milk, and/or high-quality whey protein
• Fermented foods such as kefir, kimchee, miso, pickles, sauerkraut, etc.
• Raw, organic eggs from free-ranging chickens
• Grass-fed beef
• Coconuts and coconut oil
• Locally grown fruits and vegetables, appropriate for your nutritional type
• Mushrooms, especially Reishi, Shiitake, and Maitake, which contain beta glucans (which have immune-enhancing properties)
• Garlic, a potent antimicrobial that kills bacteria, viruses AND fungi
• Herbs and spices with high ORAC scores: Turmeric, oregano, cinnamon, cloves (for more on ORAC, visitwww.oracvalues.com