When you feel a cold coming on, you might reach for a vitamin C supplement for its health-strengthening properties. “Vitamin C is an essential nutrient, which means that we need to get it from food or supplements in order for us to meet our needs,” says Tamar Samuels, RDN, cofounder of Culina Health based in New York City.
The National Institutes of Health’s Office of Dietary Supplements recommends that adults get 75 milligrams (mg) of vitamin C per day for women and 90 mg daily for men; smokers should get an additional 35 mg per day, and pregnant and breastfeeding women should get 85 and 120 mg, respectively.
RELATED: Am I Getting Enough Vitamin C?
According to the Mayo Clinic, most people source enough vitamin C through diet alone — it’s readily available in citrus fruits, peppers, tomatoes, and berries, among other fruits and vegetables. And while getting your vitamin C through food is best, you may opt for vitamin C supplements to fill in the gaps or get a higher dose. “Most vitamin C supplements start with 100 to 500 mg per capsule, which is definitely higher than the vitamin C content found in vitamin C–rich foods,” Samuels says.
That said, you may be at risk of consuming too much vitamin C if your combined intake from food and supplements exceeds 2,000 mg per day, per the ODS. And remember, it’s always a good idea to let your doctor or dietitian know about any supplements you take or plan to take, as they can be hazardous or interact with other medications you’re taking. In particular, vitamin C supplements may be harmful for people taking statins and certain types of cancer drugs.
So what are the potential benefits of higher levels of vitamin C? Here, explore five benefits of vitamin C supplements supported by research.
RELATED: The Scientific Health Benefits of Vitamin C
1. Vitamin C Supplements Can Help Reduce the Length and Severity of Illness
It’s unlikely that vitamin C can protect you from coming down with a cold, but supplementing with it may help reduce the length and severity of your sickness, according to one review. Of the studies the researchers looked at, all of which involved supplementing with more than 200 mg of vitamin C per day, some found that vitamin C reduced the duration of colds. Even though the results were somewhat varied, with some showing no benefit, the researchers concluded that supplementing with vitamin C may still be worthwhile since it’s safe and inexpensive.
Vitamin C supplements may help you recover from more serious illnesses, as well. According to a meta-analysis, vitamin C supplements reduced the length of intensive care unit stays by about 8 percent and shortened the duration of mechanical ventilation for patients by 18.2 percent. For the studies, vitamin C doses of 1,000 to 3,000 mg were used.
2. Supplementing With Vitamin C Treats Scurvy
It may come as no surprise that scurvy — a disease that results from vitamin C deficiency — is commonly treated with vitamin C supplementation. According to research, the recommendation is to take 1,000 to 2,000 mg of vitamin C for the first two or three days of treatment, 500 mg a day for the next week, then 100 mg a day for up to three months afterward.
“The majority of people treated for scurvy experience symptom improvement within 48 hours and are fully recovered within 14 days,” says Kelly Springer, RD, founder and CEO of Kelly’s Choice based in Skaneateles, New York.
RELATED: The Top Foods High in Vitamin C — and Why the Nutrient Is So Critical
3. Vitamin C Supplements Protect Various Aspects of the Heart
Vitamin C helps the heart in a few ways. For one, it may help with blood pressure management. According to one meta-analysis, vitamin C supplements (the median dose was 500 mg) helped people with high blood pressure reduce their systolic blood pressure by 4.85 millimeters of mercury (mm Hg) and their diastolic blood pressure by 1.67 mm Hg.
Other research has found that high vitamin C intake was associated with a lower risk of stroke, most significantly among those who took between 200 and 550 mg of vitamin C a day.
According to one review, vitamin C deficiency increased the risk of mortality from cardiovascular disease, likely because vitamin C may improve blood vessel function and lipid profiles.
However, the current literature provides little support for the widespread use of vitamin C supplementation to reduce cardiovascular risk or mortality. Additionally, there’s not enough research to show that vitamin C supplements can prevent cardiovascular disease or that being deficient in the vitamin may put you at increased risk of dying from it.
4. Vitamin C Can Lower the Risk of Gout
Gout, a painful form of inflammatory arthritis, is caused by having too much uric acid in the body, according to the Centers for Disease and Control Prevention. Eating a healthy diet with limited alcohol intake can lower the risk of gout — and vitamin C supplements can help as well.
“Some studies have found that vitamin C may moderately reduce uric acid levels in people who have gout,” Samuels says. According to one meta-analysis, vitamin C supplements (the median dose was 500 mg) lowered serum uric acid by 0.35 mg per deciliter (mg/dL). Normal uric acid levels are 1.5 to 6 mg/dL in women and 2.5 to 7 mg/dL in men, according to one review.
5. Vitamin C May Make Cancer Treatments More Effective
At this point, it’d be wrong to say vitamin C can prevent or cure cancer, but it may be a beneficial addition to cancer treatment. A review from 2021 found that vitamin C intake was associated with better outcomes for those with breast cancer, including lower rates of recurrence, cancer-specific mortality, and all-cause mortality.
And it appears that vitamin C may boost standard treatments as well, says Michelle Zive, PhD, RD, a nutrition coach based in San Diego. According to another review from 2021, vitamin C works with and enhances the effects of some chemotherapy and cancer drugs in those with pancreatic cancer.
It’s worth noting, however, that most of the research on this subject involves taking vitamin C intravenously rather than orally, Samuels says. Anyone undergoing cancer treatment should consult with their healthcare providers before taking vitamin C or any other supplements because of the risks of potential interactions with their cancer treatments.