Vitamin C: Immunity And Antioxidant Action

Takeaways

Vitamin C boosts immune function and acts as a powerful antioxidant

Natural sources include citrus fruits, berries, and leafy greens

Recommended daily intake varies by age, gender, and health status

Deficiency can lead to scurvy, while excess intake may cause mild side effects

Vitamin C supports collagen production, benefiting skin and overall health

Supplements come in various forms, but food sources are generally preferred

What is Vitamin C?

Vitamin C, also called ascorbic acid, is a nutrient that dissolves in water.[1] Since our bodies cannot produce it, we must obtain it through our diet or by taking supplements.[2] This important vitamin supports numerous bodily processes.

Vitamin C was identified by scientists in the 1930s while searching for a way to prevent scurvy, a disease that plagued sailors on long sea voyages.[3] It was discovered that consuming citrus fruits could prevent the illness.[4] Eventually, they isolated vitamin C as the key compound.

Our bodies do not store significant amounts of vitamin C, so we require a consistent supply through our daily diet.[5] While most animals can produce their own vitamin C, humans lost this ability over time.[6] Because of this, we rely on external sources to meet our needs.

Sources of Vitamin C

Natural Food Sources

Many fruits and vegetables contain vitamin C, with citrus fruits being a popular source. However, some foods have even higher concentrations of this vitamin. Below is a list of some excellent vitamin C sources:

Guava
Bell peppers
Kiwi fruit
Strawberries
Oranges
Papaya
Broccoli
Brussels sprouts

The amount of vitamin C in foods can vary due to several factors. These include the conditions in which they are grown, how they are stored, and the methods used to cook them.[7] Fresh, raw fruits and vegetables generally have the highest levels of vitamin C.[8]

Supplements

Vitamin C supplements are available in several forms, such as tablets, capsules, and powders. Some are flavored, and others combine vitamin C with other nutrients. The most common form is ascorbic acid, which is identical to the vitamin C found naturally in foods.[9]

Natural and synthetic vitamin C are chemically the same, and our bodies use them identically.[10] While some individuals prefer natural sources, believing they offer extra benefits, studies have not shown a clear advantage of one over the other.

Here’s a table comparing different types of vitamin C supplements:

Type	Form	Absorption	Notes
Ascorbic Acid	Powder, tablet	Good	Most common, may cause stomach upset
Sodium Ascorbate	Powder	Good	Less acidic, gentler on stomach
Calcium Ascorbate	Powder, tablet	Good	Provides calcium, less acidic
Liposomal	Liquid	Excellent	More expensive, may absorb better
Time-release	Tablet	Moderate	Releases vitamin C slowly over time

Vitamin C Functions in the Body

Antioxidant Properties

Vitamin C is a strong antioxidant, meaning it helps to protect our cells from damage caused by free radicals.[11] Free radicals are unstable molecules that can harm cells and potentially lead to disease. Vitamin C works by neutralizing these free radicals.

By acting as an antioxidant, vitamin C reduces inflammation in the body, potentially lowers the risk of certain cancers, and protects skin from sun damage.[12] These benefits contribute to overall health and may promote a longer lifespan.

The antioxidant effects of vitamin C are widespread, impacting nearly every system in our body. From our brains to our hearts, it plays a role in keeping cells healthy. This is why a sufficient intake of vitamin C is so important in our diet.

Immune System Support

Vitamin C is crucial for supporting the immune system. It aids in producing white blood cells, which fight off infections.[13] It also helps these cells function effectively, improving their ability to identify and eliminate harmful invaders.

During an infection, our vitamin C levels often decrease.[14] Taking additional vitamin C during this time may help shorten the duration and lessen the severity of colds.[15] However, it does not prevent colds entirely. Consistent intake is more beneficial than large doses taken when sick.

Here are some ways vitamin C supports immunity:

Increases production of white blood cells
Enhances white blood cell function
Strengthens skin barriers against pathogens
Accumulates in immune cells to protect them
Promotes the production of antibodies

Collagen Synthesis

Vitamin C is essential for the production of collagen, which is the most abundant protein in the body.[16] Collagen is present in our skin, bones, and blood vessels. Without adequate vitamin C, the body cannot properly produce collagen.

Collagen provides structure to the skin, keeping it firm and youthful.[17] As we age, collagen production naturally declines. Adequate vitamin C intake can help maintain healthy skin and potentially reduce the appearance of wrinkles.

Because of its role in collagen production, vitamin C also impacts wound healing.[18] When we experience a cut or injury, the body needs to create new tissue, which requires collagen. Vitamin C supports this process, potentially leading to faster healing and less scarring.

Recommended Intake

The amount of vitamin C we need varies depending on age, gender, and overall health.[19] Smokers require more vitamin C than non-smokers, and pregnant or breastfeeding women also have increased needs.[20]

Here is a table showing the recommended daily intake of vitamin C:

Age Group	Male	Female	Pregnancy	Lactation
0-6 months	40 mg	40 mg	–	–
7-12 months	50 mg	50 mg	–	–
1-3 years	15 mg	15 mg	–	–
4-8 years	25 mg	25 mg	–	–
9-13 years	45 mg	45 mg	–	–
14-18 years	75 mg	65 mg	80 mg	115 mg
19+ years	90 mg	75 mg	85 mg	120 mg

Certain conditions can increase the body’s need for vitamin C. Stress, certain medications, and malabsorption issues can deplete vitamin C levels.[21] It’s always best to seek personalized advice from a healthcare provider.

Vitamin C Deficiency

Symptoms

Vitamin C deficiency is not common in developed countries, but it can still occur. Early signs of a deficiency are often subtle and can be mistaken for other conditions. Some common symptoms include:

Fatigue and weakness
Joint pain
Dry, rough skin
Slow wound healing
Easy bruising
Swollen, bleeding gums
Nosebleeds

These symptoms can worsen over time if left untreated. A severe vitamin C deficiency can lead to scurvy, a condition that can be life-threatening.[22] Long-term deficiency can also increase the risk of developing chronic diseases.

Scurvy

Scurvy is the most severe form of vitamin C deficiency. It was historically common among sailors who lacked access to fresh fruits and vegetables. Today, scurvy is rare, but it can still occur in certain populations.

Historically, scurvy caused numerous deaths at sea. In the 18th century, a British naval physician discovered that consuming citrus fruits could prevent and treat scurvy.[23] This discovery saved countless lives and is why British sailors were nicknamed “limeys”.

Treating scurvy is straightforward; high doses of vitamin C can quickly reverse the symptoms. Prevention is even simpler with regular intake of vitamin C-rich foods. In severe cases, supplements may be required. With proper treatment, most people make a full recovery.

Potential Benefits of Vitamin C

Heart Health

Vitamin C may contribute to heart health. Some studies indicate that it can help lower blood pressure and potentially reduce the risk of heart disease.[24] While the specific mechanisms are not fully understood, its antioxidant properties are likely involved.

Research into the relationship between vitamin C and heart disease is ongoing.[25] Some studies show promising results, while others are inconclusive. Although more research is needed, consuming a diet rich in vitamin C is generally considered beneficial for heart health.

Skin Health

Vitamin C provides several benefits to the skin. It aids in collagen production, giving skin structure and firmness. It also helps protect against sun damage.[26] These effects can reduce signs of aging such as wrinkles and dark spots. Many skincare products now include vitamin C.

The antioxidant properties of vitamin C protect skin cells from damage caused by UV rays and pollution. This can contribute to a more youthful appearance. Additionally, vitamin C may help fade dark spots and create a more even skin tone.

Eye Health

Vitamin C may also benefit eye health. It is found in high concentrations within eye tissues.[27] Some research suggests it may help prevent cataracts and potentially slow the progression of age-related macular degeneration.

Research on vitamin C and its impact on eye health is still in progress. Early findings are encouraging, but further studies are necessary. A diet rich in fruits and vegetables is generally considered good for overall eye health.

Vitamin C and Other Nutrients

Vitamin C interacts with other nutrients in the body, and these interactions can either enhance or hinder its effects. Understanding these relationships can help us make better dietary choices.

One important interaction of vitamin C is with iron. It improves the absorption of iron from plant sources, which is particularly beneficial for vegetarians and vegans.[28] Consuming vitamin C-rich foods along with iron-rich plant foods can increase iron uptake.

Here’s a table showing nutrients that work well with vitamin C:

Nutrient	Interaction	Benefit
Iron	Enhances absorption	Improves iron status, especially from plant sources
Vitamin E	Regenerates vitamin E	Increases overall antioxidant protection
Flavonoids	Synergistic effects	Enhances antioxidant and anti-inflammatory actions
Selenium	Complementary antioxidant	Improves overall antioxidant status

Vitamin C Myths and Facts

Many myths surround vitamin C, such as claims that it can cure colds or that megadoses prevent cancer. It is important to distinguish fact from fiction. Below are some common myths and their factual counterparts:

Myth: Vitamin C cures colds Fact: It may reduce duration and severity, but doesn’t cure colds
Myth: More vitamin C is always better Fact: Excess vitamin C is excreted, high doses can cause side effects
Myth: Vitamin C supplements are better than food sources Fact: Food sources are generally preferred and provide other nutrients
Myth: Cooking destroys all vitamin C in foods Fact: Some is lost, but significant amounts remain in cooked foods
Myth: Vitamin C prevents all types of cancer Fact: While it may reduce risk of some cancers, it’s not a cure-all

It’s crucial to rely on evidence-based information. Many claims about vitamin C lack scientific support. Always consult reliable sources and healthcare providers for accurate information and personalized guidance.

Safety and Side Effects

Vitamin C is generally safe because it is water-soluble; any excess is usually excreted by the body.[29] However, very high doses may cause side effects. The upper limit for adults is 2000 mg per day.[40] [30]

Vitamin C toxicity is rare and typically only occurs with very high supplement doses. Symptoms may include diarrhea and stomach cramps. In extreme cases, kidney stones can form. Most individuals do not need to worry about toxicity from food sources.

Possible side effects of excessive vitamin C intake include:

Nausea and vomiting
Diarrhea
Stomach cramps
Headache
Insomnia
Increased iron absorption (a concern for some people)

Vitamin C in Special Populations

Pregnancy and Breastfeeding

Vitamin C is crucial during pregnancy and lactation for the baby’s growth and development.[31] Pregnant women need slightly more vitamin C than usual, and the same is true for breastfeeding mothers.

The recommended daily intake for pregnant women is 85 mg, and for breastfeeding women, it is 120 mg.[32] These requirements can usually be met through a balanced diet. In some cases, supplements may be needed. Always consult a healthcare provider before taking any supplements.

Smokers

Smokers have a higher need for vitamin C because smoking depletes its levels in the body and increases oxidative stress.[33] To help offset these effects, smokers need about 35 mg more vitamin C per day compared to non-smokers.[34]

Smoking affects how the body uses vitamin C, reducing its absorption and increasing its breakdown. As a result, smokers often have lower vitamin C levels. While quitting smoking is the best solution, increasing vitamin C intake can help offset some of these negative effects.

Elderly

Older adults may have an increased need for vitamin C due to potential issues with nutrient absorption.[35] Some medications can also interfere with vitamin C levels, and chronic diseases, which are more common in older adults, may also increase their need for this nutrient.

The recommended daily intake of vitamin C is the same for older adults as it is for younger adults. However, some older adults may benefit from higher intakes. A varied diet rich in fruits and vegetables is important, and supplements may sometimes be necessary. Always seek advice from a healthcare provider.

FAQ

What foods have the most vitamin C?

Foods highest in vitamin C include guava, bell peppers, kiwi, strawberries, oranges, papaya, broccoli, and Brussels sprouts.[36] Citrus fruits are well-known sources, but many other fruits and vegetables are also rich in vitamin C.

Can vitamin C prevent colds?

Vitamin C doesn’t prevent colds, but it may reduce their duration and severity.[37] Regular intake is more effective than large doses when you’re already sick. It supports immune function, which can help your body fight off infections.

How much vitamin C should I take daily?

The recommended daily intake varies by age and gender. For most adults, it’s 65-90 mg per day.[38] Pregnant and breastfeeding women need more. Smokers should add 35 mg to their daily intake. Most people can meet their needs through a balanced diet.

Is it possible to overdose on vitamin C?

It’s difficult to overdose on vitamin C from food sources.[39] However, very high doses of supplements can cause side effects like diarrhea and stomach cramps. The upper limit for adults is 2000 mg per day. Most people don’t need to worry about toxicity.

Does vitamin C interact with medications?

Vitamin C can interact with some medications.[41] It may affect how the body processes certain drugs.[42] For example, it can increase iron absorption, which could be a concern for people with iron overload disorders. Always consult your healthcare provider about potential interactions.

Can vitamin C improve skin health?

Yes, vitamin C can benefit skin health. It helps produce collagen, which gives skin structure. It also acts as an antioxidant, protecting skin from damage. Vitamin C may help reduce signs of aging and protect against sun damage. Many skincare products now include vitamin C.

Vitamin C is a versatile nutrient that offers numerous benefits. It supports the immune system and acts as a powerful antioxidant. From enhancing skin health to potentially reducing the risk of heart disease, its effects are far-reaching. Most people can obtain sufficient vitamin C from a balanced diet that includes plenty of fruits and vegetables. In some cases, supplements may be beneficial. Always consult a healthcare provider for personalized advice. Remember that vitamin C is only one component of a healthy lifestyle and should be combined with a balanced diet, regular exercise, and adequate sleep for optimal health.

Fact Check

[1]

Claim: Vitamin C, also called ascorbic acid, is a nutrient that dissolves in water.

Fact check: True. Vitamin C is a water-soluble vitamin.

Vitamin C is indeed a water-soluble vitamin, meaning it dissolves in water and is not stored in the body, requiring regular intake.

Source: “SVCT2–mediated ascorbic acid uptake buffers stress responses via DNA hydroxymethylation reprogramming of S100 calcium-binding protein A4 gene” https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9694147/

[2]

Claim: Since our bodies cannot produce it, we must obtain it through our diet or by taking supplements.

Fact check: True. Humans cannot synthesize vitamin C and must obtain it from external sources.

Humans lack the enzyme L-gulonolactone oxidase, which is needed to synthesize vitamin C internally. Therefore, dietary intake or supplements are necessary to meet our needs.

[3]

Claim: Vitamin C was identified by scientists in the 1930s while searching for a way to prevent scurvy, a disease that plagued sailors on long sea voyages.

Fact check: True. Vitamin C was identified during research aimed at preventing scurvy.

Vitamin C’s discovery was indeed tied to scurvy prevention, specifically in the 1930s. Although the disease plagued sailors centuries before, the specific identification and isolation of vitamin c was in the 30’s

[4]

Claim: It was discovered that consuming citrus fruits could prevent the illness.

Fact check: True. It was observed that citrus fruits could prevent scurvy.

Long before the discovery of vitamin C, the benefits of citrus fruits in preventing scurvy had already been observed. While it was not known why, it was still an effective remedy

[5]

Claim: Our bodies do not store significant amounts of vitamin C, so we require a consistent supply through our daily diet.

Fact check: True. The body does not store significant amounts of vitamin C, requiring regular intake.

Due to its water-soluble nature, vitamin C is not stored in the body and is readily excreted in urine. Therefore, regular consumption through diet or supplementation is needed.

[6]

Claim: While most animals can produce their own vitamin C, humans lost this ability over time.

Fact check: True. Most animals can synthesize vitamin C, but humans cannot.

Humans, along with other primates, guinea pigs, and some other species, have lost the ability to produce vitamin C internally due to a mutation in the L-gulonolactone oxidase gene.

[7]

Claim: The amount of vitamin C in foods can vary due to several factors. These include the conditions in which they are grown, how they are stored, and the methods used to cook them.

Fact check: True. Vitamin C content in foods is affected by various factors.

Environmental factors such as soil quality, sunlight exposure, storage, and cooking methods influence the vitamin C content of foods.

[8]

Claim: Fresh, raw fruits and vegetables generally have the highest levels of vitamin C.

Fact check: True. Raw, fresh produce usually retains higher vitamin C levels.

Processing, storage, and cooking can degrade vitamin C, making fresh and raw produce better sources of the vitamin.

[9]

Claim: The most common form is ascorbic acid, which is identical to the vitamin C found naturally in foods.

Fact check: True. Ascorbic acid is the chemical name for vitamin C and is identical regardless of source.

Whether derived from supplements or food, ascorbic acid is the same compound, and our bodies process it identically.

[10]

Claim: Natural and synthetic vitamin C are chemically the same, and our bodies use them identically.

Fact check: True. Natural and synthetic vitamin C are chemically indistinguishable and utilized equally by the body.

The body does not differentiate between naturally occurring vitamin C and synthetically produced ascorbic acid because they are chemically identical.

[11]

Claim: Vitamin C is a strong antioxidant, meaning it helps to protect our cells from damage caused by free radicals.

Fact check: True. Vitamin C is an antioxidant that neutralizes free radicals.

Vitamin C donates electrons to neutralize free radicals, protecting cells from oxidative damage.

[12]

Claim: By acting as an antioxidant, vitamin C reduces inflammation in the body, potentially lowers the risk of certain cancers, and protects skin from sun damage.

Fact check: Potentially True, more research is needed. Vitamin C may reduce inflammation and potentially cancer risk and sun damage. More research is needed

Vitamin C’s role as an antioxidant can contribute to reduced inflammation, but its impact on cancer prevention and sun damage protection still requires further scientific investigation. While studies are promising, more research is needed for a conclusive determination.

[13]

Claim: Vitamin C is crucial for supporting the immune system. It aids in producing white blood cells, which fight off infections.

Fact check: True. Vitamin C supports the immune system and white blood cell production.

Vitamin C is indeed important for various immune functions, including the production and function of white blood cells. This contributes to the body’s defense against infections.

[14]

Claim: During an infection, our vitamin C levels often decrease.

Fact check: True. Vitamin C levels can decrease during infections.

During times of illness and infection, the body uses more vitamin C, leading to decreased levels within the body.

[15]

Claim: Taking additional vitamin C during this time may help shorten the duration and lessen the severity of colds.

Fact check: Potentially True. Evidence suggests that vitamin C may reduce the duration and severity of colds.

While not a cure, research shows vitamin C can moderately reduce the duration and severity of colds, especially when taken regularly.

[16]

Claim: Vitamin C is essential for the production of collagen, which is the most abundant protein in the body.

Fact check: True. Vitamin C is crucial for collagen production.

Vitamin C is essential for the proper synthesis of collagen, a protein vital for many tissues including skin, bone and blood vessels.

[17]

Claim: Collagen provides structure to the skin, keeping it firm and youthful.

Fact check: True. Collagen is vital for skin structure and elasticity.

Collagen indeed provides structure, elasticity, and firmness to the skin. As collagen diminishes with age, skin is more prone to wrinkling and sagging.

[18]

Claim: Because of its role in collagen production, vitamin C also impacts wound healing.

Fact check: True. Vitamin C is crucial for wound healing due to its role in collagen synthesis.

Vitamin C supports the repair and growth of new tissue through collagen production, making it essential for effective wound healing.

[19]

Claim: The amount of vitamin C we need varies depending on age, gender, and overall health.

Fact check: True. Vitamin C requirements vary based on age, sex, and health.

The Dietary Reference Intake (DRI) for vitamin C varies based on various factors, including age, gender, and specific health conditions and lifestyle factors.

[20]

Claim: Smokers require more vitamin C than non-smokers, and pregnant or breastfeeding women also have increased needs.

Fact check: True. Smokers, pregnant women and breastfeeding mothers need higher amounts of vitamin C.

Smokers need more vitamin C due to the increased oxidative stress caused by smoking. Pregnant and breastfeeding women have higher needs to support the growth of their child.

[21]

Claim: Certain conditions can increase the body’s need for vitamin C. Stress, certain medications, and malabsorption issues can deplete vitamin C levels.

Fact check: True. Stress, certain medications and malabsorption issues can increase vitamin C requirements.

These conditions can lead to higher consumption of vitamin C in the body, thus increasing the daily requirement.

[22]

Claim: A severe vitamin C deficiency can lead to scurvy, a condition that can be life-threatening.

Fact check: True. Severe vitamin C deficiency can cause scurvy which can be life threatening.

Untreated scurvy can lead to serious complications such as tooth loss, bleeding gums, anemia, and eventually death.

[23]

Claim: In the 18th century, a British naval physician discovered that consuming citrus fruits could prevent and treat scurvy.

Fact check: True. A British naval physician, James Lind, discovered that citrus prevents and treats scurvy in the 18th century.

James Lind’s work in the 18th century demonstrated the effectiveness of citrus fruits in preventing and treating scurvy, saving many lives. His work was instrumental in understanding the cause of the disease.

Source: “How would Australian hospital staff react to an avian influenza admission, or an influenza pandemic?” https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7163727/

[24]

Claim: Vitamin C may contribute to heart health. Some studies indicate that it can help lower blood pressure and potentially reduce the risk of heart disease.

Fact check: Potentially True. Vitamin C may be associated with heart health, but more research is needed.

Although vitamin C’s antioxidant properties may benefit cardiovascular health, further research is needed to fully understand the relationship.

[25]

Claim: Research into the relationship between vitamin C and heart disease is ongoing.

Fact check: True. Research in this area is still ongoing.

Although there has been promising findings, further research is necessary in order to establish a conclusive link between vitamin C and heart disease.

[26]

Claim: Vitamin C provides several benefits to the skin. It aids in collagen production, giving skin structure and firmness. It also helps protect against sun damage.

Fact check: True. Vitamin C benefits skin by aiding collagen production and providing sun damage protection.

The antioxidant properties of vitamin C help to protect the skin and collagen production is essential for skin structure.

[27]

Claim: Vitamin C may also benefit eye health. It is found in high concentrations within eye tissues.

Fact check: Potentially True. Vitamin C is found in the eye and may support eye health.

Studies show the presence of high concentrations of vitamin C in eye tissues, and it may reduce the risk of cataracts and age-related macular degeneration. More research is needed for conclusive results

[28]

Claim: One important interaction of vitamin C is with iron. It improves the absorption of iron from plant sources, which is particularly beneficial for vegetarians and vegans.

Fact check: True. Vitamin C enhances the absorption of non-heme iron from plant sources.

Vitamin C forms a chelate with iron, making it more readily absorbed in the intestines. This is especially beneficial for vegetarians and vegans who consume non-heme iron found in plant-based foods.

[29]

Claim: Vitamin C is generally safe because it is water-soluble; any excess is usually excreted by the body.

Fact check: True. Excess vitamin C is typically excreted by the body.

As a water-soluble vitamin, the body typically excretes the excess amount of vitamin C through urine, making toxicity rare.

[30]

Claim: However, very high doses may cause side effects. The upper limit for adults is 2000 mg per day.

Fact check: True. High doses of vitamin C can cause side effects and the upper limit is 2000mg per day.

Very large doses of vitamin C can cause side effects including diarrhea and stomach cramps. The upper limit established by the National Institutes of Health is 2000mg a day.

[31]

Claim: Vitamin C is crucial during pregnancy and lactation for the baby’s growth and development.

Fact check: True. Vitamin C is essential during pregnancy and lactation.

Sufficient vitamin C is vital for the proper growth and development of the fetus during pregnancy and the newborn during lactation.

[32]

Claim: The recommended daily intake for pregnant women is 85 mg, and for breastfeeding women, it is 120 mg.

Fact check: True. The recommended daily intake for pregnant and breastfeeding women is 85mg and 120mg respectively.

The Dietary Reference Intake (DRI) for vitamin C during pregnancy is 85 mg per day and 120mg for breastfeeding women. These requirements can often be met with a balanced diet.

[33]

Claim: Smokers have a higher need for vitamin C because smoking depletes its levels in the body and increases oxidative stress.

Fact check: True. Smokers need more vitamin C due to its depletion by smoking.

Smoking increases oxidative stress and decreases vitamin C levels in the body, increasing the need for this vitamin.

[34]

Claim: To help offset these effects, smokers need about 35 mg more vitamin C per day compared to non-smokers.

Fact check: True. Smokers need about 35mg more vitamin C than non-smokers.

Smoking increases oxidative stress and decreases vitamin C levels in the body. It is recommended that smokers consume an additional 35mg daily, compared to non smokers.

[35]

Claim: Older adults may have an increased need for vitamin C due to potential issues with nutrient absorption.

Fact check: Potentially True. Older adults may require increased vitamin C, but more research is needed.

Although some older adults may be more prone to malabsorption, there is currently no difference in vitamin C intake recommendations compared to younger adults. It is important to be assessed on an individual basis.

[36]

Claim: Foods highest in vitamin C include guava, bell peppers, kiwi, strawberries, oranges, papaya, broccoli, and Brussels sprouts.

Fact check: True. These foods are good sources of vitamin C.

These foods listed are indeed high in vitamin C. Many others foods also contain vitamin C, and can be part of a balanced diet.

[37]

Claim: Vitamin C doesn’t prevent colds, but it may reduce their duration and severity.

Fact check: True. Vitamin C does not prevent colds but may reduce their duration and severity.

While vitamin C may not prevent colds entirely, studies show it can shorten the duration and reduce the severity of symptoms. It is not a cure for the common cold.

[38]

Claim: For most adults, it’s 65-90 mg per day.

Fact check: True. The recommended daily intake for most adults is 65-90mg.

The recommended dietary allowance (RDA) for vitamin C is 90mg for adult men and 75mg for adult women. These are the typical recommendations for most people. Factors such as pregnancy or smoking will increase these requirements.

[39]

Claim: It’s difficult to overdose on vitamin C from food sources.

Fact check: True. Overdosing on vitamin C through food is unlikely.

The body can usually manage the amount of vitamin C consumed through foods. An overdose usually results from taking high dose supplements.

[40]

Claim: The upper limit for adults is 2000 mg per day.

Fact check: True. The upper tolerable intake level for adults is 2000mg daily.

Although the body can typically manage the amount of vitamin C consumed, very large doses can cause side effects. The National Institute of Health has established the tolerable upper intake level as 2000mg per day.

[41]

Claim: Vitamin C can interact with some medications.

Fact check: True. Vitamin C can interact with certain medications.

Vitamin C can potentially interact with medications, particularly those metabolized by the liver and kidneys. It is recommended to consult with a healthcare professional if you have any concerns.

[42]

Claim: It may affect how the body processes certain drugs.

Fact check: True. Vitamin C can affect how the body processes some medications.

Vitamin C can interact with some medications, altering how they are absorbed, distributed, metabolized, or excreted by the body.

Medically reviewed and fact checked

January 11, 2025

Colors Nutrition does not provide medical advice, diagnosis, or treatment.

Vitamin C: Immunity and Antioxidant Action