Cold, Flu, & Cough Health Center

Vitamin C and Colds

At the very first sign of cold symptoms, many people reach for a bottle of vitamin C supplements. Vitamin C is such a widely accepted treatment for the common cold that we seek it out in lots of products such as fortified juices, cough drops, and tea.

Vitamin C was first touted for the common cold in the 1970s.

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. It has also been studied as a way to prevent colds. But findings have been inconsistent. Overall, experts have found little to no benefit in using vitamin C to prevent or treat the common cold.

In 2010, researchers looked at all the scientific studies and found that taking vitamin C every day did not prevent the number of colds that a person got. In some cases, however, it did lead to a slight improvement in symptoms. However, if the vitamin C is started after cold symptoms appear, there was no benefit seen at all.

But results were different for people who were in extreme condition, such as marathon runners. In this group, taking vitamin C on a daily basis cut their risk of catching a cold in half.

So what does all this mean?

If you take at least 0.2 grams of vitamin C every day, you are not likely to have any fewer colds. However, you may have colds that are a day or two shorter. Seven separate studies showed that when vitamin C was started after cold symptoms appeared, vitamin C was 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. Higher doses of vitamin C (greater than 2,000 milligrams per day for adults say cause kidney stones, nausea, and diarrhea.

If you're unsure about taking vitamin C for colds, talk to your health care provider. Your doctor can answer any questions about vitamin C and colds and about any other dietary supplement that you are taking.