Taking vitamin C daily (or when you’re already sick) to prevent a cold might not protect you from catching the common cold, but it can help to reduce the duration of your cold and bolster immune health.
When the weather changes seasons, most people start to experience sniffles, a runny nose, itchy eyes, and maybe even a cough—all signs that you might be getting sick. While practical advice might tell you to load up on immune-boosting nutrients, how effective are they?
You need to consume vitamin C daily to maintain health and support immune function, and many people choose to supplement with it to prevent illnesses, especially colds.
Vitamin C is an essential nutrient, but research doesn’t show it can help speed up your recovery. If you’re on the verge of a common cold and are considering taking large doses of vitamin C, keep reading to find out if it will help you.
Vitamin C and Colds: Does It Help?
When it comes to the roles of vitamin C in the body, most people are familiar with its role in immune health.
So, for anyone who has caught a common cold—or is in the process of catching one—you might turn to vitamin C to fend off what’s festering. But how helpful is this immune booster when you’re already sick?
Studies have looked at this question for years, and most research has found that doses of vitamin C when you’re sick doesn’t reduce symptom duration or severity 1.
The belief that vitamin C can treat colds is based on research by Nobel prize winner Linus Pauling and his book about cold prevention using megadoses of vitamin C—around 18,000 mg daily compared to the RDA of just 75 mg for women and 90 mg for men 1.
But while it may seem plausible, there’s little scientific backing showing that high doses of vitamin C are effective for colds. Let’s look at some of the research on this important vitamin.
A 2013 review looked at 29 studies with over 11,000 participants to determine whether vitamin C reduces the incidence, duration, or severity of the common cold when used as a continuous supplement of therapy at the onset of cold symptoms 2.
Researchers concluded that supplementing with 200 mg or more of vitamin C didn’t reduce the risk of catching a cold.
That said, there are some benefits of taking regular vitamin C supplements, including:
- Reducing the severity of common cold symptoms
- Shortened colds by up to 8% in adults and 14% in children
Some studies suggest that 1-2 grams of vitamin C can reduce the duration of a cold by an average of 18% in children, while other studies find that 6-8 grams is effective in adults 2, 3. But just how effective depends on your current state of health.
Vitamin C levels are depleted more rapidly in people who are chronically stressed or under intense acute stress, which means that supplementation may be more effective for this population 4.
Key takeaway: Vitamin C supplements may not be effective for preventing a cold, but they may help reduce the duration and severity and boost immune function.
Vitamin C may not prevent common colds, but it does boost immunity
Although taking vitamin C may not effectively reduce your cold symptoms, it still plays a vital role in the immune system.
Not only is it an important antioxidant needed to neutralize free radicals and prevent oxidative damage, but it plays several roles in immune function, including 5:
- Supports epithelial barrier function to protect the body against invading pathogens
- Promotes the oxidant scavenging activity of the skin
- Enhances chemotaxis, phagocytosis, generation of reactive oxygen species, and microbial killing
- Required for apoptosis and clearance of the used neutrophils from sites of infection
- Decreases tissue damage
- Enhances differentiation and proliferation of B- and T-cells
A vitamin C deficiency is known to impair immune function and increase susceptibility to colds and infections. But interestingly, infections have a significant impact on vitamin C levels due to enhanced inflammation and metabolic requirements 5.
If you’re looking to increase your intake of vitamin C, consuming whole foods through diet is the best and easiest way to do that since vitamin C is abundant in many fruits and vegetables.
However, vitamin C supplements can be an alternative route for those looking to consume enough vitamin C without having to eat 30 pounds of produce or a bag full of citrus fruits.
Keep in mind that too much vitamin C may also be ineffective, as high doses can have a laxative effect.
Other nutrients that keep your immune system healthy and fight sickness
There is no cure for the common cold and flu, but loading up on immune-boosting nutrients is the best way to fend off danger and accelerate recovery if you do get sick (and before a cold starts)—and there are two supplements that are gold for supporting immune health and avoiding the common cold.
Performance Lab NutriGenesis Multi is your everyday performance booster. It supplies over 100% RDI of 17+ essential vitamins and minerals in optimal forms for peak health and performance.
Engineered with NutriGenesis technology, Multi’s vitamins and minerals are highly bioavailable for maximum absorption and bioactivities.
Combine Multi with PL-Immune™ for the ultimate flu-busting duo. It’s a breakthrough immunity formula—a dynamic probiotic and antioxidant stack that activates five types of immune cells for robust responses to any challenge.
It quickly restores frontline defenses and supports your natural immune function for optimal performance and long-range health.
References
- Bucher A, White N. Vitamin C in the Prevention and Treatment of the Common Cold. Am J Lifestyle Med. 2016;10(3):181-183
- Hemilä H, Chalker E. Vitamin C for preventing and treating the common cold. Cochrane Database Syst Rev. 2013;2013(1):CD000980.
- Hemilä H. Vitamin C and Infections. Nutrients. 2017;9(4):339.
- Marik PE. Vitamin C: an essential “stress hormone” during sepsis. J Thorac Dis. 2020;12(Suppl 1):S84-S88.
- Carr AC, Maggini S. Vitamin C and Immune Function. Nutrients. 2017;9(11):1211.
