How Much Vitamin C To Take When Sick
Vitamin C is well-known for its immune-boosting benefits. You likely have vitamin C supplements in your medicine cabinet, and maybe even take them regularly during cold and flu season.
As you’ll discover in today’s article, having vitamin C on hand is helpful when you are sick. This supplement is safe, effective, and affordable. The questions that often arise are:
- Should I take vitamin C every day?
- Or begin taking it when I’m sick?
- How much should I take? Is more vitamin C better?
I’ll answer all these questions and more below. The truth is that a tiny bit of vitamin C will prevent scurvy, but there are significant benefits to higher amounts.
Keep reading to learn more about:
- Vitamin C basics
- Vitamin C and immune function
- Using vitamin C for colds and other infectious diseases
- Vitamin C dosing
- Liposomal vitamin C benefits
Let’s get started!
What is Vitamin C?
Vitamin C, also called ascorbic acid, is a water-soluble vitamin. While most mammals can synthesize vitamin C, in humans, vitamin C is an essential nutrient that we must obtain from the diet regularly. (Source 1)
The recommended amount of vitamin C is 75 milligrams for adult women and 90 mg for adult men. Meeting these minimum needs in the diet helps prevent vitamin C deficiency. (Source 2)
Extreme vitamin C deficiency, known as scurvy, leads to impaired wound healing, bleeding, and bruising. A balanced diet, including fruits and vegetables, typically provides enough vitamin C to prevent severe deficiency.
“Vitamin C, also called ascorbic acid, is a water-soluble vitamin. While most mammals can synthesize vitamin C, in humans, vitamin C is an essential nutrient that we must obtain from the diet regularly.”
Food sources of vitamin C include:
- Bell pepper
- Citrus fruits – grapefruit, oranges
- Kiwi
- Strawberries
- Broccoli
- Brussels sprouts
- Tomato
- Apples (Source 1, 2)
Vitamin C is essential for several body processes, including:
- Collagen production
- Synthesis of carnitine and neuropeptides
- Regulation of gene expression
- Antioxidant function (Source 1)
Vitamin C and the Immune System
Vitamin C is critical for immune function. As an antioxidant, it protects cells, regenerates vitamin E, and helps defend against viruses and other pathogens. It helps control inflammation and promote an effective immune response against infections. (Source 1, 3)
While we typically prevent severe vitamin C deficiency (scurvy) through diet, more than the recommended dietary intakes may be needed to optimize immunity. Even a mild lack of vitamin C may increase susceptibility to infections and impair immunity. (Source 4)
“Vitamin C is critical for immune function. As an antioxidant, it protects cells, regenerates vitamin E, and helps defend against viruses and other pathogens. It helps control inflammation and promote an effective immune response against infections.”
In addition, infections including colds, flus, and Covid, deplete vitamin C levels in the body. And using vitamin C supplements supports the prevention and treatment of respiratory infections. (Source 4)
Vitamin and the Common Cold
A 2013 systematic review and meta-analysis looked at 53 clinical trials using vitamin C doses higher than 1 gram (1000mg). This well-known, and often cited study concluded that regular vitamin C supplementation didn’t reduce the incidence of cold symptoms in the general population but did reduce the duration of colds in both children and adults. In other words, you may still get the cold, but it will be shorter and less severe. (Source 5)
The same study found that in those under heavy physical stress, including marathon runners, skiers, and soldiers, the incidence of colds was reduced by 50% with vitamin C use. The study suggests that regular use of vitamin C supplementation may be more effective than beginning vitamin C at the onset of a cold. (Source 5)
“While we typically prevent severe vitamin C deficiency (scurvy) through diet, more than the recommended dietary intakes may be needed to optimize immunity. Even a mild lack of vitamin C may increase susceptibility to infections and impair immunity.”
However, other studies suggest that beginning vitamin C at the onset of an acute respiratory infection, reduces the duration of symptoms such as a sore throat and fever. (Source 6)
Overall, there is scientific support for the use of vitamin C supplements for both the prevention and treatment of colds and flus. In addition, vitamin C is used clinically to treat Covid-19. (Source 7)
Vitamin C Supplements and Dosages<
The question begs to be asked: How much vitamin C should I take?
Eating fruits and vegetables may be enough to meet the minimal needs and prevent scurvy, but to achieve optimal wellness, many of us benefit from dietary supplements as well.
First, let’s talk about prevention. It takes about 100 to 200 mg of vitamin C daily to saturate blood plasma, cell, and tissue levels. Note that this is higher than the current recommendations. (Source 4)
This daily maintenance dosage can often be achieved through diet and taking a quality multivitamin. In addition, because vitamin C is water-soluble the capacity for storage is limited, and vitamin C needs to be consumed regularly to maintain adequate levels.
During cold and flu season, you can increase your daily dosage to support prevention. Additionally, you may want to have high doses of vitamin C on hand to begin at the first sign of a cold, flu, or Covid.
Treatment of a cold requires much higher doses of vitamin C (dosages in the grams instead of milligrams). Vitamin C demand increases during an infection, so you’ll need to replace what is depleted and provide the amount of vitamin C required by the immune system to fight the infection. (Source 4)
The upper level of vitamin C supplementation is established at 2 grams per day in adults to prevent GI symptoms. However, dosages up to 10 grams per day orally are safe and non-toxic. (Source 1)
A typical vitamin C dosage during an acute illness is 1 to 3 grams per day. This is the amount the Institute for Functional Medicine recommends taking along with other treatments for a Covid infection. (Source 7)
Be sure to discuss vitamin C supplementation and dosages with your health care provider if you take medication including chemotherapy.
Benefits of Liposomal Vitamin C
There are two main downsides to vitamin C supplementation. First, vitamin C powder tends to be poorly absorbed. And second, at high doses, vitamin C may cause gastrointestinal distress and loose stools, although other side effects are rare.
Choosing liposomal vitamin C mitigates these downsides. The liposomal delivery system mimics your own cell membranes, improving absorption and utilization in the body. In addition, liposomal vitamin C is much less likely to cause any GI symptoms compared to other vitamin C supplements. It’s much better tolerated, especially at higher, therapeutic dosages.
“There are two main downsides to vitamin C supplementation. First, vitamin C powder tends to be poorly absorbed. And second, at high doses, vitamin C may cause gastrointestinal distress and loose stools, although other side effects are rare. Choosing liposomal vitamin C mitigates these downsides.”
Read more about liposomal vitamin C and its benefits here.
Core Med Science’s Liposomal Vitamin C provides 1000 mg of vitamin C per serving (1 gram per serving). The liquid formula makes personalizing the dose easy. For example, you could take a half dose for daily preventative support and increase the dose to 1 to 3 grams per day during a cold.
Key Takeaways
Vitamin C is an essential nutrient that we need to consume daily for optimal health and immunity. Get enough vitamin C and reduce the incidence and duration of colds by:
- Eating a whole food diet, rich in fruits and vegetables
- Taking a daily multivitamin or vitamin C supplement, especially during cold and flu season
- Taking a higher dose of vitamin C at the first sign of cold symptoms, when indicated
- Choose liposomal vitamin C for improved absorption and tolerance
When you prioritize vitamin C, notice how your body responds and how you fare during this cold and flu season compared to years past.
References
- Linus Pauling Institute – Micronutrient Information Center. Vitamin C. Accessed November 25, 2022: https://lpi.oregonstate.edu/mic/vitamins/vitamin-C
- National Institutes of Health – Office of Dietary Supplements. Vitamin C Fact Sheet for Health Professionals. Accessed November 25, 2022: https://ods.od.nih.gov/factsheets/VitaminC-HealthProfessional/
- Cerullo, G., Negro, M., Parimbelli, M., Pecoraro, M., Perna, S., Liguori, G., Rondanelli, M., Cena, H., & D'Antona, G. (2020). The Long History of Vitamin C: From Prevention of the Common Cold to Potential Aid in the Treatment of COVID-19. Frontiers in immunology, 11, 574029. Full text: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7655735/
- Carr, A. C., & Maggini, S. (2017). Vitamin C and Immune Function. Nutrients, 9(11), 1211. Full text: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5707683/
- Hemilä, H., & Chalker, E. (2013). Vitamin C for preventing and treating the common cold. The Cochrane database of systematic reviews, 2013(1), CD000980. Full text: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8078152/
- Schloss, J., Lauche, R., Harnett, J., Hannan, N., Brown, D., Greenfield, T., & Steel, A. (2020). Efficacy and safety of vitamin C in the management of acute respiratory infection and disease: A rapid review. Advances in Integrative Medicine, 7(4), 187-191. Full text: https://www.sciencedirect.com/science/article/pii/S2212958820301415?via%3Dihub
- The Institute for Functional Medicine. (2020). COVID-19 Functional Medicine Resources – The Functional Medicine Approach to COVID-19: Virus Specific Neutraceutical and Botanical Agents. Accessed November 25, 2022: https://www.ifm.org/news-insights/the-functional-medicine-approach-to-covid-19-virus-specific-nutraceutical-and-botanical-agents/