- How much vitamin C do you need to stay healthy?
Does vitamin C help with colds? We know that vitamin C, or ascorbic acid as it’s also known, is necessary for the proper functioning of our immune system. So it makes sense that many of us take to popping this supplement when we feel under the weather, or as a preventative method when the weather gets cooler. But is there any evidence that it actually works?
The theory that vitamin C protects us against seasonal sniffles is relatively new, with Nobel prize winner Linus Pauling popularizing it in the early 70s. At the same time, he did not have any hard evidence to support his claim. In the following decades, many scientists tried to determine the exact effect of vitamin C on common colds, but their findings were mostly disappointing. And what’s more, recent studies have produced mixed results. So the answer to the question ‘does vitamin C help with colds?’ may not be straightforward.
So should you supplement vitamin C? Here, we look into the latest research to help you decide whether it’s worth your buck. However, it is best consult your doctor before you make any changes to your dietary routine.
What is vitamin C?
Vitamin C plays many important roles in our body, and is critical to the formation of many different tissues.
“Vitamin C is a necessary vitamin for producing collagen in the skin,” says Dr. Ioannis Liakas, medical doctor and medical director at Vie Aesthetics (opens in new tab). “Collagen is the most abundant protein in mammals, maintaining the skin and various tissues in our body tough, yet flexible. In general, a vitamin C deficiency is linked to a weakened immune system and an increase in the risk of infections.” Ascorbic acid also helps with the production of hormones, energy metabolism, neutralizing free radicals and absorbing iron in the digestive tract.
Dr. Ioannis Liakas
Dr. Ioannis Liakas has decades of experience as an NHS Consultant of Internal Medicine and Gerontologist in the U.K. He is a Fellow of the Royal College of Physicians (FRCP), Honorary Senior Lecturer at Queen Mary Medical School, and a Member of the British College of Aesthetic Medicine.
- Related: Which foods boost the immune system?
Does vitamin C have any effect on colds?
When it comes to vitamin C’s effect on colds, studies tend to produce mixed results. According to a review in the Frontiers in Immunology (opens in new tab) journal, there are currently no clinical recommendations that support using high-dose supplements of vitamin C to decrease the risk of respiratory infections in the general population. However, this practice may be advised for certain groups (such as athletes or the military) and for individuals who show signs of vitamin C deficiency.
Vitamin C supplementation may also be recommended for those at high risk of severe infection (such as the obese, diabetics or the elderly), as it may help lower inflammation (opens in new tab).
“Getting enough ascorbic acid during an infection is a great idea,” says Dr Liakas. “However, this does not mean that vitamin C can completely and effectively prevent you from getting a cold during the winter months. There is not enough evidence to show that vitamin C is an effective preventative treatment for the common cold. Instead, we know that a severe deficiency can make it harder for our bodies to fight off infection. This means that, over time, not getting enough vitamin C may increase your risk of getting sick.”
At the same time, scientists from the Life (opens in new tab) journal argue that most of current recommendations are based on highly biased studies from the late 70s. They claim that the articles from JAMA and the American Journal of Medicine rejected the evidence that vitamin C is effective against the common cold, and that their negative stance helped shape this ‘prejudiced’ discourse for years to come.
So what are the latest scientific developments regarding vitamin C and common cold — and can they provide us with definite answers?
Does vitamin C help with the prevention of colds?
According to the Nutrients (opens in new tab) journal, vitamin C is critical for maintaining the integrity of our epithelial barriers — all of the surfaces that stop any external contaminants from entering our body. Skin and intestinal walls are good examples of epithelial barriers.
Vitamin C also helps to protect our skin from pathogens by strengthening its structure and promoting its ability to ‘scavenge’ free radicals, and enhances the ability of our immune system to detect and destroy microbes before they start posing danger to our health. So in theory, vitamin C should protect us from these minor respiratory infections.
But according to a major Cochrane systematic review (opens in new tab), there is no evidence that vitamin C supplementation reduces the incidence of colds in the general population. However, it may be useful for people exposed to brief periods of severe physical exercise. Intense exercise significantly increases oxidative stress and as such, it may weaken the epithelial barriers and increase the chance of catching infections.
Does vitamin C help with the treatment of colds?
According to the Nutrients (opens in new tab) journal, vitamin C helps increase the production and proliferation of B- and T-lymphocytes. B-lymphocytes make antibodies — proteins that bind to bacteria and viruses. This process helps our immune system identify them as foreign bodies. The role of T-lymphocytes is to destroy these marked unwanted visitors. So again, in theory, vitamin C should help us shorten the duration and ease the symptoms of common colds.
And according to a meta-analysis published in the Biomed Research International (opens in new tab) journal, vitamin C can indeed help shorten the duration of colds. The time for symptom improvement and overall recovery time were better with vitamin C supplementation than with antiviral therapy alone. Results from another meta-analysis published in the Biomed Research International (opens in new tab) journal suggest that taking extra therapeutic doses at the onset of cold may also help shorten the duration of cold, as well as relieve the symptoms like chest pain, fever and chills.
- Related: Which vitamins boost the immune system?
How much vitamin C do you need to stay healthy?
The recommended daily allowance (RDA) for vitamin C depends on several factors, including age and gender. According to the NIH (opens in new tab), women should aim for 75 mg of vitamin C per day, whereas men need 90 mg. Pregnant and breastfeeding women should increase their intake. Depending on their age, they may need between 80mg to 120 mg a day. individuals who smoke also require 35 mg more per day than non-smokers.
Vitamin C is water soluble, which means that it is not stored by the body and is filtered out by the body in urine. However, high doses of vitamin C may produce unwanted side effects. The upper limit is set at 2g of this nutrient a day.
Check out these nine sources of vitamin C to boost your immune health.
This article is for informational purposes only and is not meant to offer medical advice.
Anna Gora is a Health Writer for Future Plc, working across Coach, Fit&Well, LiveScience, T3, TechRadar and Tom's Guide. She is a certified personal trainer, nutritionist and health coach with nearly 10 years of professional experience. Anna holds a BSc degree in Nutrition from the Warsaw University of Life Sciences, a Master’s degree in Nutrition, Physical Activity & Public Health from the University of Bristol, as well as various health coaching certificates. She is passionate about empowering people to live a healthy lifestyle and promoting the benefits of a plant-based diet.
More about health
Vitamin C. It appears that taking vitamin C won't usually help the average person prevent colds. However, some studies have found that taking vitamin C before cold symptoms start may shorten the length of time you have symptoms.Does vitamin C help if you're already sick? ›
Last Update: October 8, 2020; Next update: 2023. Taking vitamin C every day to try to prevent colds won't protect most people from colds. It only slightly shortens the amount of time that they're ill. Starting to take vitamin C once you already have cold symptoms won't have any effect on your cold.What vitamins help fight off colds? ›
Vitamins C and D, zinc, and Echinacea have evidence-based efficacy on these immune system barriers.How much vitamin C should I take for a cold? ›
A supplemental dose of 1–2 grams was enough to shorten the duration of a cold by 18% in children, on average ( 1 ). Other studies in adults have found 6–8 grams per day to be effective ( 2 ). Vitamin C appears to have even stronger effects in people who are under intense physical stress.How do you get rid of a cold in 24 hours? ›
There is no way to get rid of a cold fast. A cold will usually go away on its own without treatment. However, a person may experience uncomfortable symptoms while they recover. People can take steps to aid recovery, such as getting plenty of rest.What are the 5 stages of cold? ›
The stages of a cold include the incubation period, appearance of symptoms, remission, and recovery.Is zinc or vitamin C better for a cold? ›
According to the National Center for Complementary and Alternative Medicine, taking vitamin C supplements regularly slightly reduces the length and severity of colds, but some forms of zinc appear to do a better job.Does vitamin C fight off illness? ›
Despite it's popularity as a remedy for the common cold, there's actually no evidence to suggest that a large dose of vitamin C can actually prevent one — or any other type of illness, for that matter.Does vitamin C help runny nose? ›
Vitamin C acts as a natural antihistamine by reducing the amount of histamine your body produces in response to an allergen. It might help reduce mild symptoms like sneezing, runny nose, congestion, and watery eyes due to allergic rhinitis.How do you get rid of a cold quickly and easily? ›
To help you get better more quickly: rest and sleep. drink plenty of water (fruit juice or squash mixed with water is OK) to avoid dehydration. gargle salt water to soothe a sore throat (not suitable for children)
- No. 1: Blow Your Nose Often -- and the Right Way.
- No. 2: Stay Rested.
- No. 3: Gargle.
- No. 4: Drink Hot Liquids.
- No.5: Try a Lozenge to Soothe Your Throat.
- No. 6: Take a Steamy Shower.
- No. 7: Apply Hot or Cold Packs Around Your Congested Sinuses.
- No. 8: Sleep With an Extra Pillow Under Your Head.
|Best cold medicines|
|Afrin (oxymetazoline)||Decongestant||Afrin coupons|
|Mucinex D (pseudoephedrine- guaifenesin)||Decongestant – expectorant||Mucinex D coupons|
|Mucinex (guaifenesin)||Expectorant||Mucinex coupons|
|Robafen (guaifenesin)||Expectorant||Robafen coupons|
However, a 2013 meta-analysis of over 11,000 people did conclude that taking vitamin C supplements regularly (an average of 1000 mg to 2000 mg per day) slightly reduced the duration of cold symptoms and severity.Can vitamin C clear a cough? ›
Among young Norwegian adults, having a low prevalence of asthma and high prevalences of smoking-related respiratory symptoms, dietary vitamin C intake may act as an antioxidant and thereby reduce cough and wheeze in smokers having high oxidant stress.How long does a cold last? ›
In adults and older children, they usually last about 7 to 10 days, but can last longer. A cough in particular can last for two or three weeks. Colds tend to last longer in younger children who are under five, typically lasting around 10 to 14 days.Does zinc help with colds? ›
Recently an analysis of several studies showed that zinc lozenges or syrup reduced the length of a cold by one day, especially when taken within 24 hours of the first signs and symptoms of a cold.How long does cold last 3 days? ›
Colds usually last 3 to 7 days, but sometimes they hang on as long as 2 weeks. If you're under the weather for longer than that, one of these things could be to blame.How long does a cold last 2 days? ›
How Long Should a Cold Last, and What Are the Stages? Key takeaways: The common cold often follows a timeline and can last up to 3 weeks. Symptoms can take 1 to 3 days to develop, peak at 1 to 3 days, and last up to 10 days.What day is worst for cold? ›
Day 1: Fatigue, headache, sore or scratchy throat. Day 2: Sore throat worsens, low fever, mild nasal congestion. Day 3: Congestion worsens, sinus and ear pressure become very uncomfortable.Does blowing your nose help get rid of a cold? ›
But in a new study, they have found that doing so may actually make a cold worse, because the blow propels mucus into the nasal sinuses. Blowing one's nose creates a significant amount of pressure, according to Jack M.
A cold typically wraps up around day 10. There are, of course, exceptions. If you're still feeling the effects, your symptoms worsen, or your fever increases then it's time to re-evaluate and think about a different course of treatment.Do vitamins shorten a cold? ›
Vitamin C does not prevent colds and only slightly reduces their length and severity. A 2013 review of scientific literature found that taking vitamin C regularly did not reduce the likelihood of getting a cold but was linked to small improvements in cold symptoms.Is vitamin D good for colds? ›
Taking vitamin D is not a guaranteed guard against the cold or flu. But vitamin D supplements are inexpensive and might give you a boost. Vitamin D: New studies suggest that people with low blood levels of vitamin D are more likely to get sick. Researchers think that vitamin D may play a role in boosting immunity.What vitamins should you take when sick? ›
Zinc, selenium and vitamin D are known for boosting the immune system. Specifically, a 2013 review of 17 studies found that taking zinc supplements within 24 hours of the onset of symptoms reduces the duration of common cold symptoms. Tip to remember: Supplements are beneficial in moderation.Will vitamin C and zinc shorten a cold? ›
But if you've ever tried these nutrients to speed up your own recovery time, you've likely wondered just how effective they really are. The truth is, vitamin C and zinc are not effective home remedies in treating a common cold.How much vitamin D should I take to fight a cold? ›
The National Academies of Science, Engineering and Medicine recommends that most adults get about 600 international units of vitamin D per day through food or supplements, increasing that dose to 800 IUs per day for those 70 or older.Is 1000mg of vitamin C too much? ›
You should be able to get all the vitamin C you need by eating a varied and balanced diet. If you take vitamin C supplements, do not take too much as this could be harmful. Taking less than 1,000mg of vitamin C supplements a day is unlikely to cause any harm.What stops runny nose best? ›
- Drink plenty of fluids, especially water.
- Use a saline nasal spray to help relieve symptoms. ...
- A cool-mist humidifier at your bedside can combat congestion worsened by dry winter air.
An antihistamine is the best medicine for allergy-related runny noses. Antihistamines block histamines, the culprit behind common allergy symptoms such as watery eyes and runny noses. Diphenhydramine and chlorpheniramine are the two most common antihistamines, but they cause drowsiness.How do you beat a cold in one day? ›
While the duration of your symptoms may vary, many people wonder how to cure a cold in 24 hours or even overnight. The best way to tame a cold fast is to stay home, rest, drink plenty of fluids, gargle with salt water, take an OTC medication, and humidify the air.
A hot shower won't make your cold or flu disappear, but it can help you treat the uncomfortable symptoms. Benefits of hot showers include: Loosening chest congestion by breathing in steam. Clearing stuffy nasal passages with moisture.Are showers good when sick? ›
Taking a hot shower or a bath can really help to quell your various pains. The warmth from the bath can help soothe your lungs, and the steam will moisturize your throat and nasal passages that have been dried out from your sickness.Does vitamin C help break up mucus? ›
American science points towards Vitamin C being beneficial for those suffering from heavy mucus in the respiratory tract, e.g. asthmatics and others suffering from chronic sinusitis and/or chronic bronchitis.What quiets a Covid cough? ›
Fortunately, there are things you can do to treat a cough while you recover from COVID-19 at home. “It can help to elevate yourself when sleeping by slipping a wedge under your pillow,” says Klitzman. She adds, “Over-the-counter cough suppressants — antitussives — taken before bed can be very helpful.What Vitamin stops a cough? ›
Vitamin C and zinc supplements are also very common. While these supplements may shorten colds or improve coughs adults, high doses are typically used.How do I know if my cold is getting better? ›
These longer lasting symptoms may include:
- a runny nose.
- a stuffy nose.
This nighttime spike in immune system activity and inflammation can also bleed into the morning hours, he says. So if, despite your symptoms, you're able to sleep through the night, you may find that you feel worse first thing in the morning when you wake up.Is a cold contagious? ›
Viruses that cause colds can spread from infected people to others through the air and close personal contact. You can also get infected through contact with stool (poop) or respiratory secretions from an infected person.What vitamin can help you recover faster when sick? ›
Start taking a supplement.
Zinc, selenium and vitamin D are known for boosting the immune system. Specifically, a 2013 review of 17 studies found that taking zinc supplements within 24 hours of the onset of symptoms reduces the duration of common cold symptoms. Tip to remember: Supplements are beneficial in moderation.
According to the dietary guidelines, the max amount of vitamin C that is safe to take each day is 1800 milligrams. Taking in more can cause stomach upset, nausea and diarrhea, which typically resolves quickly once the usage is discontinued.
Get plenty of rest
One thing that we know for sure is that your body needs rest to recover from a cold. Even when you're healthy and well, there's a known link between getting enough sleep and having a healthy immune system. When you're sick, your body needs to direct its efforts towards fighting off infection.
The best way to beat a cold fast is to rest, drink lots of fluids, and treat the symptoms with medicines that relieve pain, coughing, and congestion.What helps cold recovery? ›
To help you get better more quickly: rest and sleep. drink plenty of water (fruit juice or squash mixed with water is OK) to avoid dehydration. gargle salt water to soothe a sore throat (not suitable for children)How long does the common cold last? ›
In adults and older children, they usually last about 7 to 10 days, but can last longer. A cough in particular can last for two or three weeks. Colds tend to last longer in younger children who are under five, typically lasting around 10 to 14 days.