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January 17, 2018

Does Vitamin C actually fight a cold?

Infrequently Asked Questions seeks the answer

It's easy to lean on oranges and Vitamin C supplements when cold season swings by for another round, but there's seldom much thought put into why the Big C is consumed in mass quantities during these periods at all.

Is it really helping to fight a cold, or is it just, possibly, a case of wishful thinking?

Curious, we reached out to Emily Scopelliti, an associate professor in Jefferson University's Department of Pharmacy, for an answer. 

People load up this time of year on Vitamin C, especially those Emergen-C supplements, thinking it's a magic fix to a cold. Is there any truth to that?

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Vitamin C is increased especially during times of a cold season, and the efficacy of a high dose of Vitamin C for preventing and treating a cold has been debated for years now. Using high doses of Vitamin C as a treatment after cold symptoms appear shows no effect on decreasing the severity of the cold or reducing the duration of the cold.

So, if you're looking to take it as a preventative, would that be effective?

It depends. There has been a review of several studies, and in general populations, supplementation doesn't really prevent colds at all. It doesn't do much for the general population, typically, but they did find that in those subjected to extreme physical exercises in cold environments--skiers, marathon runners, soldiers--they saw supplementation in those patients reduced cold incidence by half. But nothing in the general population, for data, supports either. 

I'd say overall there's insufficient evidence from studies to support supplementation regularly, beyond what is recommended as far as dietary intake is concerned.

Why would people think Vitamin C would have this effect in the first place? 

Years ago, studies were showing a possibility for immune-related response with Vitamin C, and anecdotally, I know people do truly believe in the use of Vitamin C, and I guess we're going by the fact that studies prove--again, there's not a lot of information to go by--there isn't any additional benefit, but there has been talk in the past of the potential for this.

As far as supplementation is concerned, all multivitamins have Vitamin C--anywhere from 60 to 100 mg, so that really adds up to the amount of Vitamin C that would be recommended in the diet."

In general, what does Vitamin C do for the body?

In general, Vitamin C is required for the synthesis of collagen. And that's an essential component of connective tissue. And I know you don't think of the immune system in regards to that, and [that synthesis is] really the main thing we think of in regards to Vitamin C. I don't know if you know the past history of scurvy, but that doesn't happen in the general population anymore and that's because of Vitamin C in our diet. That being said, that is the majority of, as far as the action of Vitamin C, the importance of having it in our system. As far as the cold is concerned, there isn't a lot of information in regards to the mechanism of action behind it.

Is there a vitamin that is ideal for this time of year?

As far as supplementation is concerned, all multivitamins have Vitamin C--anywhere from 60 to 100 mg, so that really adds up to the amount of Vitamin C that would be recommended in the diet. Females, the recommended intake is 75 milligrams, and males it's 90 mg. And if you eat a lot of fruits and vegetables, you do get the amount you need, as far as Vitamin C is concerned, but if you have supplementation that also includes the daily amount you would need. Emergen-C, on the other hand, has a lot more Vitamin C associated; 1,000 mg a day is what is there, but that's a supplemental dose.

I don't see the point of Emergen-C--why it exists. Your body doesn't absorb that much, right?

Exactly. The body starts excreting once it stops absorbing. And 400 mg is when you stop seeing that. High doses, typically you'll start seeing--high doses, again-- an increase of gastrointestinal problems, diarrhea or abdominal cramps. Because the body excretes it. Overall, it's safe, there's nothing to worry about in terms of typical supplementation, but definitely, don't take more than 2,000 mg of Vitamin C per day.

What are some foods people may not realize have Vitamin C? 

Our go-to food is the citrus fruits with Vitamin C. Some type of food you may not think of as having a good amount is red and green peppers. They're ranked above orange juice. If you get half a cup of red pepper, about 95 mg, that's more than you'd need for your daily intake of Vitamin C. It's called the "fresh food vitamin." Broccoli, for example. Strawberries. Grapefruit. Those types of foods.