Last update
5/15/2026
Research Authors

Overview

SCIENTIFIC SCORE
Moderately Effective
Based on 2 Researches
8
USERS' SCORE
Good
Based on 1300 Reviews
8.2
Supplement Facts
Serving Size: 1 Vegetable Capsule
Amount Per Serving
%DV
Vitamin C (as Ester-C® calcium ascorbate)
500 mg
556%
Citrus Bioflavonoid Complex
25 mg
**
Acerola Extract (Malpighia glabra) (fruit)
10 mg
**
Rose Hips (fruit)
10 mg
**
Rutin
5 mg
**
📅 Last updated:

Top Medical Research Studies

7
Effectiveness of Vitamin C on Colds
We explored the effects of vitamin C on the common cold and pneumonia by examining a range of studies. Interestingly, research on animals suggests that vitamin C may have protective effects against infections. However, when it comes to preventing colds in the general population, taking more than 1 gram of vitamin C per day didn’t show significant benefits.

But there's a twist! Participants engaged in heavy physical activities saw their cold incidence reduced by half with vitamin C supplementation. Additionally, regular intake of 1 gram or more daily was linked to a 15% decrease in cold severity. While some therapeutic trials showed inconsistent results when vitamin C was taken after cold symptoms appeared, two studies did indicate that larger doses (6-8 grams per day) could effectively shorten the duration of colds compared to lower doses.

Our investigation also looked into pneumonia, but the studies were conducted in unique settings, such as a boarding school and military recruits. This makes it hard to generalize the findings to the wider population. Yet, some trials suggested benefits for pneumonia patients. Finally, the role of vitamin C in treating COVID-19 and sepsis remains unclear, with mixed results.

Given that vitamin C seems to alleviate symptoms and shorten the duration of colds, while being safe and affordable, it might be worth considering a dose of 6-8 grams per day to see if it helps at an individual level.
Read More
9
Vitamin C improves cold tolerance
We explored the effects of ascorbic acid, commonly known as vitamin C, on cold tolerance in tomato seedlings. In our study, we discovered that applying vitamin C significantly boosts the seedlings' ability to handle cold stress.

By enhancing the antioxidant defense system, vitamin C treatment increased the enzyme activity in the seedlings' leaves. Additionally, it raised levels of important compounds such as proline, sugar, and abscisic acid, all of which play crucial roles in plant stress responses.

Our observations showed that vitamin C also protects the photosynthesis system of tomato seedlings. This implies that it helps maintain chlorophyll function, which is critical for the plant's overall health, especially under cold conditions.

Moreover, we found that vitamin C treatments led to increased expression of genes linked to antioxidant enzymes and cold response mechanisms. Overall, our findings suggest that exogenous vitamin C is a beneficial approach to improve cold tolerance in tomatoes and may provide helpful insights for farmers looking to cultivate hardier varieties during colder months.
Read More

Most Useful Reviews

9
Immune support
780 people found this helpful
This is what I drink constantly, and during a cold, I increase the dosage to 2-3 capsules per day. It helps a lot and the results are almost immediate. My immune system feels strengthened.
Read More
8
Family scheme
274 people found this helpful
We drink at the first signs of a cold. On day one, I take 2 g (4 capsules), as the hints of a cold often bring natural irritability, headaches, and fatigue. On days two to five, I reduce the dosage to 1 g and then 500 mg each day. The whole family follows this schedule after learning about it from Dr. Sophia Dorinskaya. I hope this review was helpful!
Read More
10
Stronger immunity
188 people found this helpful
I really like this vitamin C as I used to frequently catch colds. Since taking it, my immunity has significantly improved, and I practically forget about colds!
Read More

Most Recommended Products for Cold

NOW Foods Calcium & Magnesium
SCIENTIFIC SCORE
Moderately Effective
Based on 4 Researches
8.8
USERS' SCORE
Excellent
Based on 15 Reviews
9
NOW Foods 5-HTP
SCIENTIFIC SCORE
Likely Very Effective
Based on 1 Research
9
USERS' SCORE
Good
Based on 6 Reviews
8.6
Solgar L-Lysine
SCIENTIFIC SCORE
Likely Very Effective
Based on 1 Research
9
USERS' SCORE
Good
Based on 30 Reviews
8.3
Source Naturals Magnesium Malate
SCIENTIFIC SCORE
Moderately Effective
Based on 4 Researches
8.8
USERS' SCORE
Good
Based on 5 Reviews
8.4

Medical Researches

SCIENTIFIC SCORE
Moderately Effective
Based on 2 Researches
8
  • All Researches
9
Vitamin C improves cold tolerance
We explored the effects of ascorbic acid, commonly known as vitamin C, on cold tolerance in tomato seedlings. In our study, we discovered that applying vitamin C significantly boosts the seedlings' ability to handle cold stress.

By enhancing the antioxidant defense system, vitamin C treatment increased the enzyme activity in the seedlings' leaves. Additionally, it raised levels of important compounds such as proline, sugar, and abscisic acid, all of which play crucial roles in plant stress responses.

Our observations showed that vitamin C also protects the photosynthesis system of tomato seedlings. This implies that it helps maintain chlorophyll function, which is critical for the plant's overall health, especially under cold conditions.

Moreover, we found that vitamin C treatments led to increased expression of genes linked to antioxidant enzymes and cold response mechanisms. Overall, our findings suggest that exogenous vitamin C is a beneficial approach to improve cold tolerance in tomatoes and may provide helpful insights for farmers looking to cultivate hardier varieties during colder months.
Read More
7
Effectiveness of Vitamin C on Colds
We explored the effects of vitamin C on the common cold and pneumonia by examining a range of studies. Interestingly, research on animals suggests that vitamin C may have protective effects against infections. However, when it comes to preventing colds in the general population, taking more than 1 gram of vitamin C per day didn’t show significant benefits.

But there's a twist! Participants engaged in heavy physical activities saw their cold incidence reduced by half with vitamin C supplementation. Additionally, regular intake of 1 gram or more daily was linked to a 15% decrease in cold severity. While some therapeutic trials showed inconsistent results when vitamin C was taken after cold symptoms appeared, two studies did indicate that larger doses (6-8 grams per day) could effectively shorten the duration of colds compared to lower doses.

Our investigation also looked into pneumonia, but the studies were conducted in unique settings, such as a boarding school and military recruits. This makes it hard to generalize the findings to the wider population. Yet, some trials suggested benefits for pneumonia patients. Finally, the role of vitamin C in treating COVID-19 and sepsis remains unclear, with mixed results.

Given that vitamin C seems to alleviate symptoms and shorten the duration of colds, while being safe and affordable, it might be worth considering a dose of 6-8 grams per day to see if it helps at an individual level.
Read More

User Reviews

USERS' SCORE
Good
Based on 1300 Reviews
8.2
  • All Reviews
  • Positive Reviews
  • Negative Reviews
9
Immune support
780 people found this helpful
This is what I drink constantly, and during a cold, I increase the dosage to 2-3 capsules per day. It helps a lot and the results are almost immediate. My immune system feels strengthened.
Read More
8
Family scheme
274 people found this helpful
We drink at the first signs of a cold. On day one, I take 2 g (4 capsules), as the hints of a cold often bring natural irritability, headaches, and fatigue. On days two to five, I reduce the dosage to 1 g and then 500 mg each day. The whole family follows this schedule after learning about it from Dr. Sophia Dorinskaya. I hope this review was helpful!
Read More
10
Stronger immunity
188 people found this helpful
I really like this vitamin C as I used to frequently catch colds. Since taking it, my immunity has significantly improved, and I practically forget about colds!
Read More
10
Prevents colds
138 people found this helpful
Vitamin C is vital, especially since our bodies cannot synthesise it. I take 500 mg twice daily with meals, and if I feel a cold coming on, I bump it up to 3 grams; this has always restored my health. After nearly ten years of taking it, we haven’t caught a cold!
Read More
9
Effective for colds
114 people found this helpful
Vitamin C is always in my first aid kit. It helps during the flu and cold season, and I take it as soon as I notice the first symptoms. The results have been excellent, and it can be taken by those with stomach issues.
Read More

Frequently Asked Questions

No FAQs are available for this product and symptom.

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. Wang X, Ran C, Fu Y, Han L, Yang X, et al. Application of Exogenous Ascorbic Acid Enhances Cold Tolerance in Tomato Seedlings through Molecular and Physiological Responses. Int J Mol Sci. 2024;25. 10.3390/ijms251810093
image