News Perspectives

Vitamin C and Colds

Regularly taking vitamin C doesn't usually keep people from catching colds, but it might make their colds end a little faster, says an article published June 28 in U.S. News and World Report. The article is based on a review of 55 previous studies, published June 27 in the journal PLoS (Public Library of Science) Medicine. According to the review, most studies found that taking the vitamin didn't help after symptoms started, but in one large study people who took 8,000 milligrams on the first day of symptoms recovered faster, U.S. News reported. People exposed to extreme physical stress -- such as marathon runners -- also got only half as many colds if they regularly took vitamin C.

Vitamin C and Colds

Healing power of vitamin C questioned

By Cory Hatch

Vitamin C, long in the vanguard of the war against wintertime sniffles, has fallen under scrutiny in recent years because scientific evidence of its effectiveness remains scant. Recently, researchers compiled data from 55 studies to find out if vitamin C really works to fight the common cold.

What the researchers wanted to know: Does vitamin C really work to prevent or treat colds?

What they did: The researchers compiled data from 55 different studies dating from 1940 to 2004 that looked at how well doses of at least 200 mg per day of vitamin C prevented or treated the common cold when compared with a placebo.

What they found: Most of the time, vitamin C didn't keep people from catching colds. However, when people, especially children, took vitamin C before they became sick, the illness didn't last as long. Most studies showed that the vitamin didn't help people who waited until after the onset of symptoms to take vitamin C, although one large study found that already-sick patients who took 8,000 mg on the first day of their illness got better faster. One group of people did seem to benefit more than others: Marathon runners, skiers, and soldiers exposed to extreme cold or physical exertion got sick 50 percent less often when they took vitamin C as a preventive measure.

What this study means to you: Vitamin C seems to work for people whose bodies are exposed to lots of physical stress, such as endurance athletes, skiers, soldiers, and other people who exercise intensely or spend a lot of time in freezing temperatures. For everyone else, especially children, starting a daily vitamin C regimen won't stop you from getting sick, but it might help you recover faster from the colds you do catch. Those who forget their daily dose of vitamin C are out of luck. Once you're already sick, one massive dose (8,000 mg) might help, though the jury is still out.

Caveats: Since this paper is a compilation of many studies, the authors had little control over the experimental design or the quality of the data. Also, the papers that showed the benefits of vitamin C for those who exercise were based primarily on marathon runners, and the results may not be applicable to people who participate in less taxing exercise regimens. None of the studies looked at how well vitamin C works as a treatment for already-sick children.

Find out more: If you don't like popping pills but still want a daily dose of vitamin C, the Ohio State University website has a list of foods that contain the nutrient naturally. The Linus Pauling Institute (named for the Nobel Prize-winning chemist who first popularized vitamin C) at Oregon State University has good vitamin C information on its website.

Read the article: Douglas, R.M. and Hemila, H. "Vitamin C for Preventing and Treating the Common Cold." Public Library of Science Medicine. June 2005, Vol. 2, No. 5, pp. 132-133.

From NLM:

Vitamin C = ascorbic acid

Vitamin C: Vitamin C has been in the public eye for a long time. Even before its discovery in 1932, nutrition experts recognized that something in citrus fruits could prevent scurvy, a disease that killed as many as 2 million sailors between 1500 and 1800. More recently, Nobel laureate Linus Pauling promoted daily megadoses of vitamin C (the amount in 12 to 24 oranges) as a way to prevent colds and protect the body from other chronic diseases.

There's no question that vitamin C plays a role in controlling infections. It's also a powerful antioxidant that can neutralize harmful free radicals, and it helps make collagen, a tissue needed for healthy bones, teeth, gums, and blood vessels. The question is, do you need lots of vitamin C to keep you healthy?

No. Vitamin C's cold-fighting potential certainly hasn't panned out. Small trials suggest that the amount of vitamin C in a typical multivitamin taken at the start of a cold might ease symptoms, but there's no evidence that megadoses make a difference, or that they prevent colds. Studies of vitamin C and heart disease, cancer, and eye diseases such as cataract and macular degeneration also show no clear patterns.

Optimal Intake: The current recommended dietary intake for vitamin C is no good evidence that megadoses of vitamin C improve health. As the evidence continues to unfold, 200 to 300 mg of vitamin C a day appears to be a good target. This is easy to hit with a good diet and a standard multivitamin. Excellent food sources of vitamin C are citrus fruits or citrus juices, berries, green and red peppers, tomatoes, broccoli, and spinach. Many breakfast cereals are also fortified with vitamin C.

From IH:

The common cold, also known as an upper respiratory infection (URI), tends to affect the nose and throat. It is caused by many viruses, including rhinoviruses, adenoviruses, and respiratory syncytial virus. Symptoms include stuffy nose, sneezing, scratchy throat, hoarse voice, dry cough (usually from mucous dripping down the throat), and slight fever. Most people get better completely within five days, though sometimes the symptoms can last up to two weeks. Even with cold symptoms, people generally can keep up with their usual activities.

These viruses are spread through physical contact, such as when you touch, kiss or shake hands with infected people and their secretions (for example, from a runny nose) and then touch your eyes, mouth, or nose with the dirty hand. Many viruses can live for at least half an hour on the hands and for several hours on countertops, toys, and other surfaces. They also are spread through the air, on tiny droplets of infected water that come out when someone with a cold or flu sneezes or coughs near you.

Since prevention truly is the best medicine, use careful hygiene and regular housecleaning to help prevent these respiratory illnesses. Wash your hands often, and teach your children to wash theirs, scrubbing with soap and warm water for at least 15 seconds (about as long as one verse of "Happy Birthday"). You can also use one of the alcohol-based hand cleaners (even though they are called antibacterial gels, they also kill viruses). Change cloth towels often and launder them in hot water. Use disposable tissues when wiping noses, and wear a mask if you are coughing or sneezing frequently. Regularly wipe down all surfaces, including toys, with a virus-killing disinfectant. Finally, try to avoid exposing young children, particularly infants, to secondhand tobacco smoke, which increases the risk of severe viral respiratory infections.

Get Your Flu Shot Now!

Most cases of the flu can be prevented with the influenza vaccine (flu shot) which is safe for children as young as 6 months of age. Because young children are at higher risk of getting very sick from the flu, it is suggested that the flu shot be routinely offered to ALL children between 6 months and 24 months of age. The flu shot is recommended especially for children who have certain diseases that put them at risk of serious complications from the flu, including significant heart disease, lung disease (for example, asthma or cystic fibrosis), diabetes, sickle-cell disease, kidney disease, muscular dystrophy, or HIV infection.

Everyone who should or wants to be vaccinated against the flu must receive the flu vaccine every year, because the viral strains from last year’s vaccine will not fully protect against the viral strains expected to be around the United States this year. Flu shots are usually given as early as possible between October and December for maximum protection throughout the winter flu season. Children younger than 9 years of age who have never had a flu shot before need two doses of the vaccine at least one month apart.

A different flu vaccine (FluMist) that can be sprayed up the nose (instead of a shot) is also available. It protects against the same strains of the flu as the flu shot, but it can only be given to people between the ages of 5 and 49 years. Because it is not a shot, some children may be more accepting of this type of vaccine. However, this vaccine contains a weak but “live” form of the virus and cannot be given to children who have problems with their immune system.

What Is It?

The common cold, also called viral rhinitis, is one of the most common infectious diseases in humans. Although the infection is usually mild and improves without treatment, it causes widespread illness and discomfort, resulting in nearly 26 million days of missed school and 23 million days of absence from work every year in the United States. The average American has 1 to 3 colds per year.

The common cold is an upper respiratory infection that is caused by a wide variety of viruses. More than 200 viruses that can cause the common cold have been identified. The biggest offender, called the rhinovirus, causes up to 40 percent of colds and has 100 distinct types. Other important upper respiratory viruses include coronaviruses, adenovirus and respiratory syncytial virus. This incredible diversity has made the development of a vaccine for the common cold almost impossible.

Rhinoviruses, the most likely agents to cause colds, have a well-established seasonal pattern, peaking in the early fall and spring. Other viruses tend to cause winter colds, which are usually more debilitating. Despite popular belief, cold temperatures do not appear to increase either the incidence or severity of the common cold. There is no evidence that exposure to cold or rainy weather makes you more likely to catch a cold.

Symptoms

The common cold causes a group of symptoms that usually are easily recognized by patients and doctors. About 50 percent of patients will develop a sore throat, which is often the first symptom to appear because it can occur as early as 10 hours after infection. This is followed rapidly by the most common symptoms of the common cold — congested nasal and sinus passages, a runny nose and sneezing. Hoarseness and cough are less likely to occur, but they may last longer than other symptoms, sometimes for several weeks. However, high fevers and chills are rare with the common cold.

Diagnosis

Most people diagnose the common cold by the typical symptoms of runny nose, congestion and sneezing, and rarely consult a health care professional. High fevers, severe sinus pain, shortness of breath and new wheezing are symptoms that suggest you either have something other than a cold or a complication of the cold.

Expected Duration

Symptoms typically peak on the second, third or fourth day of infection and last about one week. People are most infectious (likely to pass the cold onto others) during the first 24 hours of the illness, and they usually remain infectious for as long as the symptoms last. Up to 25% of people may have persistent symptoms, such as a nagging cough that can last for several weeks. A small number of people may develop another illness, such as a bacterial infection of the middle ear or the sinuses, and others may develop bronchitis or worsening of asthma. These patients may have a prolonged illness.

Prevention

Colds most often are spread to people in close contact. Usually about half of the family members of an infected person will become ill. Colds also are transmitted frequently in schools and day care facilities.

The common cold most often is transmitted by direct contact with the respiratory secretions of someone who is infected, usually by hand-to-hand contact. The infected respiratory secretions are passed from one person's hand to another. The second person then touches his or her eyes or rubs his or her nose, spreading the virus there, where it can cross the delicate membranes and cause infection. It is also possible to become infected by touching a surface, such as a tabletop or doorknob, that was recently touched by an infected person, and then touching your eyes or nose.

To avoid getting a cold, it is extremely important to clean your hands often, carefully dispose of all used tissues, and avoid rubbing your eyes and nose. These viruses also can be spread by inhaling particles from the air after an infected person has coughed or sneezed. If possible, you should avoid close, prolonged exposure to people who have colds.

People who exercise regularly, especially those who exercise daily, have fewer colds per year than those who are less active.

Treatment

Although medical therapies can improve the symptoms of the common cold, they do not prevent, cure or shorten the illness. It's important to drink enough fluids, get plenty of rest, and treat your symptoms to keep yourself as comfortable as possible. Gargling warm salt water can soothe a sore throat. Inhaling steam may improve nasal congestion temporarily. Over-the-counter cold remedies, including decongestants and cough suppressants, will help to relieve congestion and cough. Antihistamines may improve the symptoms of runny nose and watery eyes, but they should be used with care because over-the-counter versions cause sedation. It is important to keep in mind that antibiotics do not cure the common cold or shorten the length of time that symptoms last. Vitamin C, zinc and echinacea (a frequently used herbal therapy) have been widely rumored to decrease the likelihood of developing the common cold and to shorten symptoms, but no conclusive research has demonstrated that this is true.

When To Call A Professional

A small percentage of people who have a common cold develop bacterial infections of the middle ear, sinuses or lungs. If you develop high fevers, severe pain over your sinuses, severe wheezing or shortness of breath, you should see your physician to be sure that you don't have a more serious illness, such as pneumonia, bacterial sinusitis or a middle ear infection.

Prognosis

The common cold usually causes a mild infection that improves on its own within a week. However, some people may have symptoms that last for several weeks, and a small number of patients may develop bacterial infections of the ear, sinuses or lungs following the common cold.

What Is the Doctor's Reaction?

Do you believe in the healing power of vitamin C? Is there any evidence that it actually works? These are questions worth asking. Millions of people are already convinced - they regularly take vitamin C to prevent the common cold or to treat symptoms as soon as they begin.

Ignoring the recommendations of my friends and family, I never take vitamin C for colds.  The few studies I’ve read on the subject did not convince me that it worked. And I know that when I have a cold, it will probably go away fairly quickly without vitamin treatment. But maybe there are studies proving that vitamin C is effective about which I have been unaware.

For anyone wondering about whether or not to take vitamin C, researchers have just published an important study.  They searched the medical literature for every study since 1940 that evaluated the capacity of vitamin C (at a dose of at least 200 mg/day) to combat symptoms of the common cold. After analyzing the data from 55 studies, the findings were mostly disappointing:

• When vitamin C was taken to prevent colds, most studies found no major benefit

• Most studies also found no benefit to taking vitamin C to treat symptoms of a cold

• One large study found that study subjects taking a very large dose of vitamin C (8000 mg) at the start of a cold got better faster; but other studies have not confirmed this.

On the positive side, vitamin C did seem to help in certain situations:

• People who took vitamin C while healthy had a somewhat shorter duration of cold symptoms than those who did not; this was especially true for children

• Adults involved with intensive athletic activities or exposed to extreme cold, such as marathon runners, skiers and soldiers, had a 50 percent reduction in the frequency of catching colds; it’s not clear whether this benefit would be expected with less intense exercise or in other environmental conditions

The recommended daily allowance of vitamin C is just 75 mg for women, 90 mg for men; most people who eat a balanced diet easily get this much. In fact, it’s easy to consume the significantly higher doses of vitamin C that were studied as potentially helpful to fight off colds. By maintaining a balanced diet - especially one that contains citrus juices and fruits, tomatoes, broccoli and other vegetables and fortified breakfast cereals - and by taking a daily multivitamin, most people can readily get 200 to 300 mg of vitamin C each day. And this does not require taking an additional vitamin C supplement.

What Changes Can I Make Now?

While there are a number of changes you can make to reduce your risk of catching a cold or to lessen symptoms once you’re sick, taking extra vitamin C is probably not a treatment that will help much or at all.

To lessen your chances of catching a cold, be sure to get enough rest, avoid others who are sick and encourage them to cover their mouths when coughing or sneezing; wash your hands often and encourage sick contacts to do the same. Of note, people who exercise regularly seem to get fewer colds than those who are more sedentary.

Many people with colds expect to be treated with an antibiotic. While antibiotics are good for bacterial infections they are ineffective against viruses such as those causing the common cold.

Once you have a cold, drink plenty of fluids and get lots of rest; warm salt water gargling or lozenges can help relieve a sore, scratchy throat. Inhaled steam and over-the-counter decongestants and antihistamines can reduce congestion and other cold symptoms but be wary of side effects and interactions with other medications you may be taking. For example, non-prescription antihistamines tend to be quite sedating.

Is it possible you are not getting enough vitamin C to stay healthy? Deficiency in vitamin C is called “scurvy,” a condition marked by easy bruising, joint pain, leg swelling, and depression. Scurvy is quite rare in places where people have adequate access to food. In this country, most cases are noted among people who are severely malnourished, including those who are living in poverty, addicted to drugs or alcohol, or chronically ill with poor dietary intake. If you have concerns about your diet or are worried you might have vitamin C deficiency, be sure to discuss it with your doctor.

What Can I Expect Looking to the Future?

You can expect additional research to better define the health benefits and risks of vitamin C. It’s possible that vitamin C can have much more profound benefits for conditions other than the common cold. For example, there has been considerable interest in vitamin C treatment as a way to lower the risk of atherosclerosis; however, the best research has suggested little or no benefit and at least one study found that high doses actually accelerated vascular disease. Another recent study suggested that vitamin C might be helpful for patients with gout because it lowered the blood level of uric acid (which deposits in joints and causes joint inflammation).

What dose if vitamin C is best? Are there risks associated with taking higher than recommended doses of vitamin C over the long-term? Are there better ways to prevent or treat the common cold? Clearly, more high quality research is needed before new recommendations can be made; until then, it’s probably best to wash your hands often, stick to a healthy, well-balanced diet, and, if you like, take a multivitamin each day.