Vitamin C is an essential vitamin, meaning it can’t be produced by the body. Nevertheless, it has many roles in your body and has been linked to impressive health benefits.
It is water-soluble and found in many fruits and vegetables, including oranges, strawberries, kiwi fruit, bell peppers, broccoli, kale and spinach.
The recommended daily intake for vitamin C is 75 mg for women and 90 mg for men (1).
While it’s commonly advised to get your vitamin C intake from foods, many people turn to supplements to meet their needs.
Here are 7 scientifically proven benefits of taking a vitamin C supplement.
Antioxidants are molecules that boost the immune system. They do so by protecting cells from harmful molecules called free radicals.
When free radicals accumulate, they can promote a state known as oxidative stress, which has been linked to many chronic diseases ().
Studies show that consuming more vitamin C can increase your blood antioxidant levels by up to 30%. This helps the body's natural defenses fight inflammation (, 5).
Summary Vitamin C is a strong antioxidant that can boost your blood antioxidant levels. This may help reduce the risk of chronic diseases like heart disease.
Approximately one-third of American adults have high blood pressure ().
High blood pressure puts you at risk of heart disease, the leading cause of death globally (7).
Studies have shown that vitamin C may help lower blood pressure in those both with and without high blood pressure.
An animal study found that taking a vitamin C supplement helped relax the blood vessels that carry blood from the heart, which helped reduce blood pressure levels ().
Moreover, an analysis of 29 human studies found that taking a vitamin C supplement, on average, reduced systolic blood pressure (upper value) by 3.84 mmHg and diastolic blood pressure (lower value) by 1.48 mmHg in healthy adults.
In adults with existing high blood pressure, vitamin C supplements reduced systolic blood pressure by 4.85 mmHg and diastolic blood pressure by 1.67 mmHg, on average ().
While these results are promising, it’s not clear if the effects on blood pressure are long-term. Moreover, people with high blood pressure should not rely on vitamin C alone for treatment.
Summary Vitamin C supplements have been found to lower blood pressure in both healthy adults and adults with existing high blood pressure.
Heart disease is the number one cause of death worldwide (7).
Many factors increase the risk of heart disease, including high blood pressure, high levels of “bad” LDL cholesterol, low levels of “good” HDL cholesterol and triglyceride levels.
Vitamin C may help reduce these risk factors, which may reduce heart disease risk.
For example, an analysis of nine studies with a combined 293,172 participants found that after 10 years, people who took at least 700 mg of vitamin C daily had a 25% lower risk of heart disease than those who did not take a vitamin C supplement ().
Interestingly, another analysis of 15 studies found that consuming vitamin C only from foods, not supplements, was linked to a lower risk of heart disease.
However, scientists were unsure if people who consumed vitamin C-rich foods also followed a healthier lifestyle than people who took a supplement. Thus, it remains unclear if the differences were due to vitamin C or other aspects of the diet ().
Another analysis of 13 studies looked at the impact of taking at least 500 mg/day of vitamin C on risk factors for heart disease, such as blood cholesterol and triglyceride levels.
The analysis found that taking a vitamin C supplement significantly reduced “bad” LDL cholesterol by approximately 7.9 mg/dl and blood triglycerides by 20.1 mg/dl ().
In short, it seems that taking or consuming at least 500 mg of vitamin C daily may reduce the risk of heart disease. However, if you already consume a vitamin C-rich diet, then supplements may not provide additional heart health benefits.
Summary Vitamin C supplements have been linked to a reduced risk of heart disease. These supplements may lower heart disease risk factors, including “bad” LDL cholesterol and blood triglycerides.
Gout is a type of arthritis that affects approximately 4% of American adults ().
It is incredibly painful and involves inflammation of the joints, especially those of the big toes. People with gout experience swelling and sudden, severe attacks of pain ().
Gout symptoms appear when there is too much uric acid in the blood. Uric acid is a waste product produced by the body. At high levels, it may crystallize and deposit in the joints.
Interestingly, several studies have shown that vitamin C may help reduce uric acid in the blood and, as a result, protect against gout attacks.
For example, a study of 1,387 men found that people who consumed the most vitamin C had significantly lower blood levels of uric acid than those who consumed the least ().
Another study followed 46,994 healthy men over 20 years to see if vitamin C intake was linked to developing gout. Interestingly, people who took a vitamin C supplement had a 44% lower gout risk ().
Additionally, an analysis of 13 clinical studies found that taking a vitamin C supplement over 30 days significantly reduced blood uric acid, compared to a placebo ().
While there appears to be a strong link between vitamin C intake and uric acid levels, more studies on the impact of vitamin C on gout are needed.
Summary Vitamin C-rich foods and supplements have been linked to reduced blood uric acid levels and lower risk of gout.
Iron is an important nutrient that has a variety of functions in the body. It is essential for making red blood cells and transporting oxygen throughout the body.
Interestingly, vitamin C supplements can help improve the absorption of iron from the diet. Vitamin C assists in converting iron that is poorly absorbed, such as plant-based sources of iron, into a form that is easier to absorb ().
This is especially useful for people on a meat-free diet, as meat is a major source of iron.
In fact, simply consuming 100 mg of vitamin C may improve iron absorption by 67% ().
As a result, vitamin C may help reduce the risk of anemia among people prone to iron deficiency.
In one study, 65 children with mild iron deficiency anemia were given a vitamin C supplement. Researchers found that the supplement alone helped control their anemia ().
If you suffer from low iron levels, consuming more vitamin C-rich foods or taking a vitamin C supplement may help improve your blood iron levels.
Summary Vitamin C can improve the absorption of iron that is poorly absorbed, such as iron from meat-free sources. It may also reduce the risk of iron deficiency.
One of the main reasons people take vitamin C supplements is to boost their immunity.
Vitamin C is involved in many parts of the immune system.
First, vitamin C helps encourage the production of white blood cells known as lymphocytes and phagocytes, which help protect the body against infections ().
Second, vitamin C helps these white blood cells function more effectively while protecting them from damage by potentially harmful molecules, such as free radicals.
Third, vitamin C is an essential part of the skin’s defense system. It is actively transported to the skin where it can act as an antioxidant and help strengthen the skin’s barriers (22).
Studies have also shown that taking vitamin C may shorten wound healing time (, ).
What’s more, low vitamin C levels have been linked to poor health outcomes.
For example, people who suffer from pneumonia tend to have lower vitamin C levels, and vitamin C supplements have been shown to shorten the recovery time (, 26).
Summary Vitamin C may boost immunity by helping white blood cells function more effectively, strengthening your skin’s defense system and helping wounds heal faster.
Dementia is a broad term used to describe symptoms of poor thinking and memory.
It affects over 35 million people worldwide and typically occurs among older adults ().
Studies suggest that oxidative stress and inflammation near the brain, spine and nerves (altogether known as the central nervous system) can increase the risk of dementia ().
Vitamin C is a strong antioxidant. Low levels of this vitamin have been linked to an impaired ability to think and remember (, ).
Moreover, several studies have shown that people with dementia may have lower levels of vitamin C in the blood (, ).
Furthermore, high vitamin C intakes from food or supplements have been shown to have a protective effect on thinking and memory with age (, , ).
Vitamin C supplements may aid against conditions like dementia if you do not get enough vitamin C from the diet. However, more human-based studies are needed in order to understand the impact of vitamin C supplements on nervous system health ().
Summary Low vitamin C levels have been linked to an increased risk of memory and thinking disorders like dementia, while a high intake of vitamin C from foods and supplements has been shown to have a protective effect.
While vitamin C has many scientifically proven benefits, it also has many unfounded claims supported by either weak evidence or no evidence at all.
Here are some unproven claims about vitamin C:
- Prevents the common cold: While vitamin C appears to reduce the severity of colds and the recovery time by 8% in adults and 14% in children, it is not able to prevent them (37).
- Reduces cancer risk: A handful of studies have linked vitamin C intake to a lower risk of several cancers. However, most studies have found that vitamin C does not affect the risk of developing cancer ().
- Protects against eye diseases: Vitamin C has been linked to reduced risks of eye diseases like cataracts and age-related macular degeneration. However, vitamin C supplements have no effect or may even cause harm (, , ).
- May treat lead toxicity: Although people with lead toxicity appear to have low vitamin C levels, there is no strong evidence from human studies that show vitamin C can treat lead toxicity ().
Summary Although vitamin C has many proven benefits, it has not been shown to prevent the common cold, reduce cancer risk, protect against eye diseases or treat lead toxicity.
Vitamin C is a water-soluble vitamin that must be obtained from the diet or supplements.
It has been linked to many impressive health benefits, such as boosting antioxidant levels, reducing blood pressure, reducing heart disease risk, protecting against gout attacks, improving iron absorption, boosting immunity and reducing dementia risk.
Overall, vitamin C supplements are a great and simple way to boost your vitamin C intake if you struggle to get enough from your diet.