Can Vitamin C Actually Shorten A Cold? What’s Fact vs. Fiction

We've all been there, reaching for some extra vitamin C (whether that’s orange juice or a supplement) in hopes of warding off germs or at the first signs of a runny nose and cough.

When it comes to immunity, vitamin C is a key player. It has potent anti-inflammatory capabilities that are essential in bolstering the body’s immune response across multiple organ systems. 

This vitamin is involved in the production, regulation, and function of different types of leukocytes, such as neutrophils—white blood cells that continuously patrol the body to keep it safe.   

And when you contract a common cold (which is caused by a virus that typically enters through your nose or mouth), your immune system launches an attack. One of the first things it does is initiate an inflammatory response—which contributes to those pesky cold symptoms—and activates white blood cells to start fighting the infection. 

Even if you aren’t fighting an active infection, you need to get enough vitamin C daily to help fuel immune cell function and keep your immune system resilient1. 

Vitamin C won’t necessarily prevent you from catching a cold (if the virus enters your boy, it enters your body). 

But, getting sufficient amounts of vitamin C can shorten a cold. The kicker is: You can’t just increase your intake when you start feeling sick and expect the vitamin C to work overnight. 

Instead, research shows that taking vitamin C regularly (not just when symptoms start) may shorten the duration of a cold by about a day2 and even lessen its severity3.  

While this may not seem like much, a less severe cold means less disruptions to your daily life. Of course, resting and taking it easy when you're sick is important, but some things (like taking kids to school, cooking meals, doing laundry, working from home, etc.) are far more manageable. 

At a minimum, shoot for 90 milligrams a day through food. That’s equivalent to just ½ cup of raw red bell pepper or one large orange. 

So even though getting enough seems simple, about 46% of U.S. adults fall short of getting enough vitamin C daily. 

Increasing your intake of vitamin C-rich foods is a great place to start (here’s what to add to your plate).  

However, research shows much higher doses —up to 1,000 milligrams daily4—are needed for cold support. So if you want help covering all your vitamin C needs, a specific vitamin C supplement is the way to go.