What does Vitamin C do in the body?

Vitamin C (ascorbic acid) supports immune function, helps form collagen for skin and connective tissue, and acts as an antioxidant. It also improves absorption of non-heme iron from plant foods.

What are the best food sources of Vitamin C?

Common sources include citrus fruits, berries, kiwi, peppers, broccoli, and tomatoes. Because it is water-soluble and heat-sensitive, minimal cooking can help preserve it.

How much Vitamin C should I take daily?

Many supplements provide 250–1000 mg per day, but needs vary by diet and health status. Getting Vitamin C from foods is generally sufficient for most people.

Can Vitamin C help prevent or treat colds?

Regular Vitamin C intake may slightly reduce cold duration in some people, but it does not reliably prevent colds for everyone. It is not a substitute for medical care if symptoms are severe or persistent.

Is too much Vitamin C harmful?

High doses can cause gastrointestinal upset such as diarrhea or stomach cramps. People with certain medical conditions or those prone to kidney stones should discuss supplementation with a clinician.

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Vitamin B

Vitamin B1 (Thiamine)

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Vitamin A & Carotenoids

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Vitaminoids

Trimethylglycine (Betaine)

NMN (Nicotinamide Mononucleotide)

Pyrroloquinoline Quinone (PQQ)

D-Chiro-Inositol

Coenzym Q10 (Ubiquinone)

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Nicotinamide Riboside

Vitamin B8 (Myo-Inositol)

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Coenzyme Q10 (Ubiquinol)

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Calcium Alpha-Ketoglutarate

Magnesium

Magnesium Bisglycinate

Magnesium L-Threonate

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Copper (Bisglycinate)

Chromium Picolinate

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Pentadecanoic Acid (C15:0)

Phosphatidylserine

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Black Cumin Oil

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Phospholipids

Algae Oil

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Docosapentaenoic acid (DPA)

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Bifidobacterium longum BB536

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Vitamin C

Strong study situation·10/10

A higher score indicates better study conditions, but not necessarily effectiveness.

Vitamin C (ascorbic acid) is a water-soluble essential nutrient with antioxidant, immune, and collagen-supportive roles.

Eye Health Tissue Repair Essential Nutrient Antioxidant Immune Booster Skin Health Anemia Support

dose range

250–1000 mg

once or twice daily with meals

Consumption

Take with meals to reduce risk of gastrointestinal discomfort.

Not fat-soluble.

Best time

Best taken with food; split doses may improve absorption at higher intakes.

Description

Vitamin C is required for normal growth, tissue repair, bone health, and immune function. It acts as a potent antioxidant and is found mostly in fruits and vegetables, such as citrus and peppers. While deficiency (scurvy) is rare in developed countries, supplementation is common for specific groups or health goals.

benefits

Main effects with level of evidence

Strong

Note on evidence

Strong evidence supports Vitamin C's essential role in tissue repair, collagen synthesis, immune function, and antioxidant capacity; evidence for other proposed benefits varies.

Supports immune function

Strong

Vitamin C contributes to the normal function of the immune system, enhancing white cell activity and epithelial barrier integrity; supplementation may slightly reduce cold duration in some populations.

Particularly relevant for: general population · athletes · immunocompromised · elderly

nih_ods_vitamin_c · NIH Office of Dietary Supplements: Vitamin C Fact Sheet pubmed_review · Carr AC, Maggini S. Vitamin C and Immune Function. Nutrients (2017)cochrane_cold · Cochrane Review: Vitamin C for preventing and treating the common cold

Provides antioxidant protection

Strong

Acts as a powerful antioxidant, helping protect cells from free radical damage and reducing oxidative stress, potentially supporting cardiovascular and overall health.

Particularly relevant for: general population · smokers

nih_ods_vitamin_c · NIH Office of Dietary Supplements: Vitamin C Fact Sheet efsa_vitamin_c · European Food Safety Authority: Vitamin C harvard_vitamin_c · Harvard T.H. Chan: Vitamin C

Promotes collagen synthesis and tissue repair

Strong

Vitamin C is required for collagen formation, supporting skin, bones, teeth, cartilage, and wound healing.

Particularly relevant for: general population · elderly · athletes · post-surgical

nih_ods_vitamin_c · NIH Office of Dietary Supplements: Vitamin C Fact Sheet efsa_vitamin_c · European Food Safety Authority: Vitamin C mayo_vitamin_c · Mayo Clinic: Vitamin C

Enhances iron absorption

Moderate

Increases non-heme iron absorption from plant foods, which may reduce risk of iron deficiency anemia, especially in at-risk groups.

Particularly relevant for: vegetarians · pregnant women · people with anemia

nih_ods_vitamin_c · NIH Office of Dietary Supplements: Vitamin C Fact Sheet efsa_vitamin_c · European Food Safety Authority: Vitamin C

Supports eye health (macular degeneration)

Moderate

Vitamin C, in combination with other antioxidants, may help slow progression of age-related macular degeneration (AMD) based on AREDS trial results.

Particularly relevant for: elderly · at risk for AMD

nih_ods_vitamin_c · NIH Office of Dietary Supplements: Vitamin C Fact Sheet harvard_vitamin_c · Harvard T.H. Chan: Vitamin C

Safety & Information

Important safety information & known risks

For educational purposes only • not medical advice

Vitamin C is generally safe within recommended levels, but high doses can cause gastrointestinal symptoms or increase risk of kidney stones, particularly in predisposed individuals.

warning notices

High intakes over time may cause kidney stones, especially in those with renal disorders or a history of oxalate stones.
Rarely, very high doses may cause iron overload in individuals with hemochromatosis.
Avoid doses above 2,000 mg/day to reduce risk of gastrointestinal symptoms and kidney stones, especially if you have a history of kidney disease or stones.
Consult a healthcare provider before use if undergoing chemotherapy or taking statins, warfarin, or estrogen, as interactions are possible.
Use only with clinician supervision if you have hemochromatosis or other iron overload conditions.

Known interactions with medications

chemotherapy agents
statins
warfarin
estrogen therapies

Contraindications / special precautions

kidney disease
history of kidney stones
hemochromatosis or iron overload conditions

interactions

Important interactions between active ingredient ↔ supplement / medication / food

Vitamin C can impact absorption and effect of several nutrients and medications.

Vitamin C enhances absorption of non-heme iron from plant sources.

nutrient · iron

PairStrongTake together

Why

Vitamin C reduces non-heme iron to a more absorbable form.

recommendation

Pair Vitamin C with iron-rich plant foods or supplements.

nih_ods_vitamin_c · NIH Office of Dietary Supplements: Vitamin C Fact Sheet

High-dose Vitamin C supplements may interfere with some chemotherapy drugs.

drug · chemotherapy

CautionModerateRelevant for certain cancer drugs; always discuss with oncologist.

Why

As an antioxidant, vitamin C could reduce the oxidative stress needed for certain chemotherapy agents' efficacy.

recommendation

Consult an oncologist before using vitamin C supplements during chemotherapy.

nih_ods_vitamin_c · NIH Office of Dietary Supplements: Vitamin C Fact Sheet mayo_vitamin_c · Mayo Clinic: Vitamin C

Potential interactions of high-dose vitamin C with statins, warfarin, and estrogen therapies.

drug · statins, warfarin, estrogen

CautionLimitedRelevant for higher supplement doses (>1,000 mg/d) or long-term use.

Why

Vitamin C may alter plasma concentrations or metabolize some drugs, though clinical significance at dietary doses is unclear.

recommendation

Monitor closely if combining high-dose supplements with these medications.

nih_ods_vitamin_c · NIH Office of Dietary Supplements: Vitamin C Fact Sheet mayo_vitamin_c · Mayo Clinic: Vitamin C

Excessively high doses of Vitamin C may reduce copper absorption.

nutrient · copper

CautionLimitedHigh doses >1,500 mg/d and sustained use.

Why

Pharmacological Vitamin C can chelate copper, decreasing its bioavailability.

recommendation

Avoid very high-dose supplementation over extended periods unless supervised.

efsa_vitamin_c · European Food Safety Authority: Vitamin C

mechanisms of action

Brief explanations of how it works

Antioxidant activity

Vitamin C neutralizes free radicals, reducing cellular oxidative damage and supporting immune defense.

nih_ods_vitamin_c · NIH Office of Dietary Supplements: Vitamin C Fact Sheet pubmed_review · Carr AC, Maggini S. Vitamin C and Immune Function. Nutrients (2017)

Cofactor for collagen synthesis

Acts as a required cofactor in collagen biosynthesis, necessary for connective tissue, skin, bones, and wound healing.

nih_ods_vitamin_c · NIH Office of Dietary Supplements: Vitamin C Fact Sheet efsa_vitamin_c · European Food Safety Authority: Vitamin C

Enhances iron absorption

Reduces non-heme dietary iron to its absorbable ferrous state, increasing iron uptake from plant foods.

nih_ods_vitamin_c · NIH Office of Dietary Supplements: Vitamin C Fact Sheet

Sources & References

Primary literature and reviews on which these statements are based

8 sources

nih_ods_vitamin_c

NIH Office of Dietary Supplements: Vitamin C Fact Sheet

mayo_vitamin_c

Mayo Clinic: Vitamin C

efsa_vitamin_c

European Food Safety Authority: Vitamin C

examine_vitamin_c

Examine.com: Vitamin C

pubmed_review

Carr AC, Maggini S. Vitamin C and Immune Function. Nutrients (2017)

harvard_vitamin_c

Harvard T.H. Chan: Vitamin C

cochrane_cold

Cochrane Review: Vitamin C for preventing and treating the common cold

(Hemilä and Chalker, 2013)

healthline_vitamin_c

Healthline: Vitamin C Benefits

Laatst bijgewerkt: 13 februari 2026

This information is for educational purposes only and does not replace medical advice.