Skip to content
My WebMD Sign In, Sign Up

Cold, Flu, & Cough Health Center

Select An Article
Font Size

Vitamin C for the Common Cold

At the very first sign of cold symptoms, many people reach for Vitamin C, whether in supplements, juices, cough drops, tea, or other forms.

Vitamin C was first touted for the common cold in the 1970s. But despite its widespread use, experts say there's very little proof that vitamin C actually has any effect on the common cold.

Recommended Related to Cold & Flu

Top 13 Flu Myths

Myths about the flu are everywhere. According to many experts, misconceptions and rumors about the flu are as hard to contain and as hard to fight as the virus itself.  “There are urban myths and rural myths about the flu,” says William Schaffner, MD, chairman of the department of preventive medicine at Vanderbilt University’s School of Medicine in Nashville, Tenn. “Flu myths are everywhere.” Unfortunately, flu myths are common even among the people who should know better, like health care workers...

Read the Top 13 Flu Myths article > >

What Is Vitamin C?

Vitamin C is an important vitamin and antioxidant that the body uses to keep you strong and healthy. Vitamin C is used in the maintenance of bones, muscle, and blood vessels. Vitamin C also assists in the formation of collagen and helps the body absorb iron.

Vitamin C is found naturally in vegetables and fruits, especially oranges and other citrus fruits. This key vitamin is also available as a natural dietary supplement in the form of vitamin C pills and vitamin C chewable tablets.

Can Vitamin C Prevent or Treat Cold Symptoms?

Vitamin C has been studied for many years as a possible treatment for colds, or as a way to help prevent colds. But findings have been inconsistent. Overall, experts have found little to no benefit from vitamin C for preventing or treating the common cold.

In a July 2007 study, researchers wanted to discover whether taking 200 milligrams or more of vitamin C daily could reduce the frequency, duration, or severity of a cold. After reviewing 60 years of clinical research, they found that when taken after a cold starts, vitamin C supplements do not make a cold shorter or less severe. When taken daily, vitamin C very slightly shorted cold duration -- by 8% in adults and by 14% in children.

So what does all this mean?

According to this research, the average adult who suffers with a cold for 12 days a year would still suffer for about 11 days a year if that person took a high dose of vitamin C every day during that year.

For the average child who suffers about 28 days of cold illness a year, taking daily high-dose vitamin C would still likely mean about 24 days of cold illness.

When vitamin C was tested for treatment of colds in 7 separate studies, it was found to be no more effective than placebo at shortening the duration of cold symptoms.

Is Vitamin C Safe to Take?

In general, vitamin C is safe to take when ingested through food sources such as fruits and vegetables. For most people, taking vitamin C supplements in the recommended amounts is also safe. The RDA or recommended daily allowance is 90 mg for men and 75 mg for women. High doses of vitamin C (greater than 2000 milligrams per day for adults) may cause kidney stones, nausea, and diarrhea.

If you're unsure about taking vitamin C for colds, talk to your health care provider. 

WebMD Medical Reference

Reviewed by David T. Derrer, MD on August 01, 2014
Next Article:

Today on WebMD

hot toddy
15 tips to help you feel better.
man sneezing into elbow
Do echinacea and vitamin C really help a cold?
 
teen girl coughing
Get a good night’s rest with these remedies.
elder berry
Eat these to fight colds, flu, and more.
 
Natural Cold Flu Remedies Slideshow
Slideshow
blowing nose
VIDEO
 
Allergy And Sinus Symptom Evaluator
Health Check
Boy holding ear
Article
 
woman receiving vaccine shot
Article
Bacterial or Viral Infection
Video
 
How To Calm Your Cough
Quiz
Sore Throat
Slideshow
 

WebMD Special Sections