Overview

SCIENTIFIC SCORE
Possibly Effective
Based on 7 Researches
7.4
USERS' SCORE
Good
Based on 90 Reviews
8.1
Supplement Facts
Serving Size:  1 Tablet
Amount Per Serving
%DV
Vitamin C (as Ascorbic Acid)
500 mg
556%
Rose Hips Powder (Rosa canina) (fruit)
40 mg

Top Medical Research Studies

We explored how vitamin C affects the severity of common colds through a comprehensive review of available studies. By including only randomized, placebo-controlled trials where participants received at least 1 gram of vitamin C daily, we aimed to investigate both the overall duration of colds and the intensity of symptoms experienced.

Our analysis found that vitamin C significantly reduced the severity of cold symptoms by about 15%. Interestingly, it appears that the benefits are more pronounced for those experiencing severe symptoms compared to mild ones. In specific comparisons, vitamin C didn’t substantially affect the duration of mild symptoms but had a notable impact on how long severe symptoms lasted.

This insight is crucial, as the common cold often leads to absenteeism at work and school, with more severe symptoms playing a key role in this setback. By highlighting vitamin C's greater effectiveness against intense cold symptoms, we suggest that future research should continue to look into how this vitamin can be utilized in managing cold severity.
Read More
8
Vitamin C's potential benefits highlighted
We assessed the longstanding debate about vitamin C’s effectiveness in treating the common cold. This exploration reveals that evidence has consistently indicated that vitamin C can indeed help reduce the duration and severity of cold symptoms in certain circumstances.

However, despite this evidence, mainstream medicine has often favored what we call eminence-based medicine, relying on influential figures rather than empirical data. The skepticism surrounding vitamin C largely traces back to three pivotal studies published in 1975, two in JAMA and one in the American Journal of Medicine. These studies have shaped the narrative in textbooks and nutritional guidelines, despite exhibiting notable flaws that we carefully examined.

Furthermore, we highlighted misleading reporting in recent randomized trials and critical editorials published in JAMA regarding vitamin C. While our critique largely focuses on this journal, it reflects a broader trend across medical literature, indicating a possible bias against acknowledging the benefits of vitamin C in fighting colds.
Read More
8
Vitamin C reduces cold incidence
We conducted an insightful study to explore whether vitamin C supplementation can help reduce the incidence of common colds among Republic of Korea Army recruits. Our research involved a rigorous randomised, placebo-controlled trial that included 1,444 soldiers over a 30-day period.

In this study, we divided the participants into two groups: one received a daily dose of 6,000 mg of vitamin C while the other received a placebo with no vitamin C. We investigated the soldiers' medical records to see how many of them contracted a cold during the training period.

Our findings showed encouraging results. The group that took vitamin C had a 20% lower risk of developing a common cold compared to those who took the placebo. Interestingly, this protective effect was especially pronounced among recruits in certain training camps, as well as never smokers and those who were physically ranked at level three.

Overall, we observed that vitamin C supplementation appears to be an effective strategy for reducing the incidence of common colds in military settings, which may lead to considerations for implementing vitamin C provisions during basic training for soldiers.
Read More

Most Useful Reviews

9
Prevents common cold
295 people found this helpful
Vitamin C from iHerb has been part of my first aid kit for three years, and I've purchased it five times. I typically take 3000-4000 mg at the first signs of a common cold, which usually stops it from developing. I now take one 500 mg tablet daily, as I have iron deficiency anaemia. The packaging is convenient, and the vitamins are easy to swallow. However, it’s crucial to monitor blood thickness when taking vitamin C.
Read More
9
Fast recovery
9 people found this helpful
Excellent vitamin C in an easy-to-manage dosage. I can adjust the dose by splitting the tablet. For common cold symptoms, my family takes a specific regimen that helps us recover quickly. We all benefit from it, including my parents.
Read More
9
Strengthens immunity
8 people found this helpful
This vitamin is essential now, particularly for combating viruses. The Now company offers a fantastic product at a good price. My family takes it regularly, and during a common cold, I increase my intake without concern, although I've noticed a tendency for heartburn over time. I began taking two tablets daily when I caught the flu, and I felt better in under a week.
Read More

Medical Researches

SCIENTIFIC SCORE
Possibly Effective
Based on 7 Researches
7.4
  • All Researches
9
Vitamin C aids common cold recovery
We explored the potential benefits of vitamin C as a supplementary treatment for relieving common cold symptoms. By analyzing data from 10 randomized controlled trials, all focused on patients in China, we sought to understand how combining vitamin C with antiviral therapy might enhance recovery.

Our findings revealed that vitamin C supplementation could significantly improve overall efficacy, with a reported relative risk of 1.27. Moreover, it was shown to shorten the time it takes for symptoms to get better and for patients to heal, compared to antiviral therapy alone.

While vitamin C seems to have a positive impact when paired with antiviral drugs, it’s essential to note that its individual effects might not be fully clear due to the combined treatment approach used in the studies. Nonetheless, vitamin C presents itself as a promising addition to traditional cold treatments, helping patients manage their symptoms more effectively.
Read More
We explored how vitamin C affects the severity of common colds through a comprehensive review of available studies. By including only randomized, placebo-controlled trials where participants received at least 1 gram of vitamin C daily, we aimed to investigate both the overall duration of colds and the intensity of symptoms experienced.

Our analysis found that vitamin C significantly reduced the severity of cold symptoms by about 15%. Interestingly, it appears that the benefits are more pronounced for those experiencing severe symptoms compared to mild ones. In specific comparisons, vitamin C didn’t substantially affect the duration of mild symptoms but had a notable impact on how long severe symptoms lasted.

This insight is crucial, as the common cold often leads to absenteeism at work and school, with more severe symptoms playing a key role in this setback. By highlighting vitamin C's greater effectiveness against intense cold symptoms, we suggest that future research should continue to look into how this vitamin can be utilized in managing cold severity.
Read More
8
Vitamin C's potential benefits highlighted
We assessed the longstanding debate about vitamin C’s effectiveness in treating the common cold. This exploration reveals that evidence has consistently indicated that vitamin C can indeed help reduce the duration and severity of cold symptoms in certain circumstances.

However, despite this evidence, mainstream medicine has often favored what we call eminence-based medicine, relying on influential figures rather than empirical data. The skepticism surrounding vitamin C largely traces back to three pivotal studies published in 1975, two in JAMA and one in the American Journal of Medicine. These studies have shaped the narrative in textbooks and nutritional guidelines, despite exhibiting notable flaws that we carefully examined.

Furthermore, we highlighted misleading reporting in recent randomized trials and critical editorials published in JAMA regarding vitamin C. While our critique largely focuses on this journal, it reflects a broader trend across medical literature, indicating a possible bias against acknowledging the benefits of vitamin C in fighting colds.
Read More
8
Vitamin C reduces cold incidence
We conducted an insightful study to explore whether vitamin C supplementation can help reduce the incidence of common colds among Republic of Korea Army recruits. Our research involved a rigorous randomised, placebo-controlled trial that included 1,444 soldiers over a 30-day period.

In this study, we divided the participants into two groups: one received a daily dose of 6,000 mg of vitamin C while the other received a placebo with no vitamin C. We investigated the soldiers' medical records to see how many of them contracted a cold during the training period.

Our findings showed encouraging results. The group that took vitamin C had a 20% lower risk of developing a common cold compared to those who took the placebo. Interestingly, this protective effect was especially pronounced among recruits in certain training camps, as well as never smokers and those who were physically ranked at level three.

Overall, we observed that vitamin C supplementation appears to be an effective strategy for reducing the incidence of common colds in military settings, which may lead to considerations for implementing vitamin C provisions during basic training for soldiers.
Read More
We investigated how vitamin C affects the common cold, focusing on its potential for prevention and treatment. Research indicates that while vitamin C does not prevent colds in the general population when taken at doses over 1 g/day, it has been beneficial for individuals engaging in heavy physical activity, effectively halving their incidence of colds.

Looking into regular supplementation, we found that taking 1 g or more daily can reduce the severity of colds by about 15%. However, when it comes to starting vitamin C after cold symptoms begin, results are less consistent, though higher doses of 6-8 g/day did significantly shorten the duration of colds compared to lower doses.

Interestingly, historical studies showed that vitamin C might prevent pneumonia in specific populations, such as schoolboys or soldiers, but this doesn’t translate to the general public. While some trials indicated potential benefits for pneumonia patients, the evidence is not conclusive.

Overall, we see that given the evidence supporting reduced severity and duration of colds, along with its safety and affordability, it may be worth considering a higher dose of vitamin C for those looking to manage cold symptoms better.
Read More

User Reviews

USERS' SCORE
Good
Based on 90 Reviews
8.1
  • All Reviews
  • Positive Reviews
  • Negative Reviews
9
Prevents common cold
295 people found this helpful
Vitamin C from iHerb has been part of my first aid kit for three years, and I've purchased it five times. I typically take 3000-4000 mg at the first signs of a common cold, which usually stops it from developing. I now take one 500 mg tablet daily, as I have iron deficiency anaemia. The packaging is convenient, and the vitamins are easy to swallow. However, it’s crucial to monitor blood thickness when taking vitamin C.
Read More
9
Fast recovery
9 people found this helpful
Excellent vitamin C in an easy-to-manage dosage. I can adjust the dose by splitting the tablet. For common cold symptoms, my family takes a specific regimen that helps us recover quickly. We all benefit from it, including my parents.
Read More
9
Strengthens immunity
8 people found this helpful
This vitamin is essential now, particularly for combating viruses. The Now company offers a fantastic product at a good price. My family takes it regularly, and during a common cold, I increase my intake without concern, although I've noticed a tendency for heartburn over time. I began taking two tablets daily when I caught the flu, and I felt better in under a week.
Read More
9
Helps during colds
7 people found this helpful
Just a wonderful vitamin C. I drink it during a common cold, and it helps a lot!
Read More
9
Effective against viruses
7 people found this helpful
I recommend this product. I've ordered Vitamin C from this company for years and I'm very happy. It's especially beneficial for adults and children during virus season. If I feel unwell, I take 4 tablets a day along with other vitamins. It’s my go-to for common colds!
Read More

Frequently Asked Questions

9
Effective relief
1 people found this helpful
Whenever I or a family member feels a sore throat approaching a common cold, we take a Now C-500. Within hours, the pain subsides. Now, my entire family also purchases this product.
9
Strengthens immunity
8 people found this helpful
This vitamin is essential now, particularly for combating viruses. The Now company offers a fantastic product at a good price. My family takes it regularly, and during a common cold, I increase my intake without concern, although I've noticed a tendency for heartburn over time. I began taking two tablets daily when I caught the flu, and I felt better in under a week.
9
Viral protection
2 people found this helpful
This Vitamin C is effective for viral infections. At the first signs of illness, I take two pills, while my son takes one. Most times, this stops the common cold before it starts. They should be taken with water, not chewed, as they are sour. I’m pleased with the quality and quantity per jar.
9
Boosts immunity
1 people found this helpful
Good Vitamin C. This is not my first purchase. It's effective for people with normal and low acidity. Vitamin C boosts immunity, accelerates wound healing, and aids the pancreas among other benefits. The addition of rose hips enhances immunity and combats infections. I've hardly had a common cold in two years.
9
Prevents illness
5 people found this helpful
We all take these tablets during the cold and flu season. We switched from synthetic vitamins to these natural ones from NOW Foods and it’s been rewarding. We take one tablet for prevention daily and can increase to four if anyone feels unwell. It helps us avoid the common cold!
9
Effective against viruses
7 people found this helpful
I recommend this product. I've ordered Vitamin C from this company for years and I'm very happy. It's especially beneficial for adults and children during virus season. If I feel unwell, I take 4 tablets a day along with other vitamins. It’s my go-to for common colds!
We investigated how vitamin C affects the common cold, focusing on its potential for prevention and treatment. Research indicates that while vitamin C does not prevent colds in the general population when taken at doses over 1 g/day, it has been beneficial for individuals engaging in heavy physical activity, effectively halving their incidence of colds.

Looking into regular supplementation, we found that taking 1 g or more daily can reduce the severity of colds by about 15%. However, when it comes to starting vitamin C after cold symptoms begin, results are less consistent, though higher doses of 6-8 g/day did significantly shorten the duration of colds compared to lower doses.

Interestingly, historical studies showed that vitamin C might prevent pneumonia in specific populations, such as schoolboys or soldiers, but this doesn’t translate to the general public. While some trials indicated potential benefits for pneumonia patients, the evidence is not conclusive.

Overall, we see that given the evidence supporting reduced severity and duration of colds, along with its safety and affordability, it may be worth considering a higher dose of vitamin C for those looking to manage cold symptoms better.
8
Vitamin C reduces cold incidence
We conducted an insightful study to explore whether vitamin C supplementation can help reduce the incidence of common colds among Republic of Korea Army recruits. Our research involved a rigorous randomised, placebo-controlled trial that included 1,444 soldiers over a 30-day period.

In this study, we divided the participants into two groups: one received a daily dose of 6,000 mg of vitamin C while the other received a placebo with no vitamin C. We investigated the soldiers' medical records to see how many of them contracted a cold during the training period.

Our findings showed encouraging results. The group that took vitamin C had a 20% lower risk of developing a common cold compared to those who took the placebo. Interestingly, this protective effect was especially pronounced among recruits in certain training camps, as well as never smokers and those who were physically ranked at level three.

Overall, we observed that vitamin C supplementation appears to be an effective strategy for reducing the incidence of common colds in military settings, which may lead to considerations for implementing vitamin C provisions during basic training for soldiers.
We explored the role of Vitamin C in managing common cold symptoms through a review of existing studies. The focus was to understand whether this popular vitamin could help in reducing the incidence of the common cold or its severity.

Our findings revealed that Vitamins C, D, and E did not notably lower the incidence of the common cold in the general population. However, we did discover something interesting: Vitamin C appeared to be beneficial in individuals experiencing physical or environmental stress, reducing the incidence of the cold by half in those specific circumstances.

Moreover, while Vitamin C did not prevent colds, it did play a role in shortening their duration and minimizing the severity of symptoms. On the other hand, large doses of Vitamin A showed no effects on pneumonia recovery, and Zinc had some benefits for children under five, particularly in improving clinical deterioration.

Despite the inconclusive results regarding Vitamin C and overall cold prevention, it seems that taking this vitamin during stressful periods may still offer some advantages. Overall, while the results are mixed, there's potential for Vitamin C to be a helpful component in managing colds for specific groups.

References

  1. Hemilä H, Chalker E. Vitamin C for the common cold and pneumonia. Pol Arch Intern Med. 2025;135. 10.20452/pamw.16926
  2. Hemilä H, Chalker E. Vitamin C reduces the severity of common colds: a meta-analysis. BMC Public Health. 2023;23:2468. 10.1186/s12889-023-17229-8
  3. Hemilä H, Chalker E. Bias against Vitamin C in Mainstream Medicine: Examples from Trials of Vitamin C for Infections. Life (Basel). 2022;12. 10.3390/life12010062
  4. Murni IK, Prawirohartono EP, Triasih R. Potential Role of Vitamins and Zinc on Acute Respiratory Infections Including Covid-19. Glob Pediatr Health. 2021;8:2333794X211021739. 10.1177/2333794X211021739
  5. Ran L, Zhao W, Wang H, Zhao Y, Bu H. Vitamin C as a Supplementary Therapy in Relieving Symptoms of the Common Cold: A Meta-Analysis of 10 Randomized Controlled Trials. Biomed Res Int. 2020;2020:8573742. 10.1155/2020/8573742
  6. Schloss J, Lauche R, Harnett J, Hannan N, Brown D, et al. Efficacy and safety of vitamin C in the management of acute respiratory infection and disease: A rapid review. Adv Integr Med. 2020;7:187. 10.1016/j.aimed.2020.07.008
  7. Kim TK, Lim HR, Byun JS. Vitamin C supplementation reduces the odds of developing a common cold in Republic of Korea Army recruits: randomised controlled trial. BMJ Mil Health. 2022;168:117. 10.1136/bmjmilitary-2019-001384
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