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Vitamin C is an essential vitamin that must be consumed in the diet. Good sources include fresh fruits and vegetables, especially citrus fruits.
Vitamin C is needed for the body to develop and function properly. It plays an important role in immune function. Most experts recommend getting vitamin C from the diet rather than taking supplements. Fresh oranges and fresh-squeezed orange juice are good sources.
Historically, vitamin C was used for preventing and treating scurvy. Today, people most commonly use vitamin C for preventing and treating the common cold. It's also used for autism, breast cancer, heart disease and many other conditions, but there is no good scientific evidence to support many of these uses. There is also no good evidence to support using vitamin C for COVID-19.
- Vitamin C deficiency. Oral or intramuscular vitamin C is effective for preventing or treating vitamin C deficiency.
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- Anemia of chronic disease. Oral vitamin C seems to improve markers of anemia in patients on hemodialysis.
Login for details - Atrial fibrillation. Oral and intravenous vitamin C seems to help prevent atrial fibrillation after cardiac surgeries.
Login for details - Bowel preparation. Powdered vitamin C is approved for use as part of a polyethylene glycol-based bowel preparation for colonoscopy.
Login for details - Common cold. Oral high-dose vitamin C might modestly reduce cold symptoms; however, taking vitamin C prophylactically does not seem to prevent the development of a cold.
Login for details - Complex regional pain syndrome. Taking oral vitamin C after surgery seems to reduce the risk of developing complex regional pain syndrome.
Login for details - Exercise-induced respiratory infections. High-dose oral vitamin C seems to reduce the risk of respiratory infections associated with strenuous exercise.
Login for details - Hypercholesterolemia. Oral vitamin C seems to reduce lipid levels in patients with hypercholesterolemia.
Login for details - Hypertension. Oral vitamin C seems to modestly reduce blood pressure in patients with hypertension.
Login for details - Laser skin resurfacing. Topical vitamin C seems to reduce erythema occurring after cosmetic laser skin resurfacing procedures intended to reduce scars and wrinkles.
Login for details - Lead toxicity. Dietary vitamin C seems to lower concentrations of lead in the blood.
Login for details - Nitrate tolerance. Oral vitamin C might prevent nitrate tolerance in some patients.
Login for details - Postoperative pain. Oral or intravenous vitamin C might prevent acute postoperative pain. It is unclear if vitamin C reduces chronic postoperative pain.
Login for details - Wrinkled skin. Topical vitamin C might reduce the appearance of existing wrinkles.
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- Acute bronchitis. Oral vitamin C doesn't seem to improve symptoms of acute bronchitis.
Login for details - Asthma. Oral vitamin C doesn't seem to prevent asthma or improve lung function.
Login for details - Atherosclerosis. Oral vitamin C does not seem to reduce the progression of atherosclerosis.
Login for details - Bladder cancer. Oral vitamin C does not reduce the risk of bladder cancer or mortality from bladder cancer.
Login for details - Cardiovascular disease (CVD). Oral vitamin C does not seem to be beneficial for either primary or secondary CVD prevention.
Login for details - Colorectal cancer. Oral vitamin C does not seem to prevent colorectal cancer.
Login for details - Coronavirus disease 2019 (COVID-19). Oral high-dose vitamin C does not seem to speed recovery from COVID-19 in non-hospitalized patients. Additionally, early research suggests that intravenous vitamin C may not improve outcomes in patients hospitalized with COVID-19.
Login for details - Fetal and premature infant mortality. Oral vitamin C does not seem to prevent neonatal death.
Login for details - Fractures. Oral vitamin C does not seem to improve fracture healing.
Login for details - Helicobacter pylori. Oral vitamin C does not seem to improve eradication of H. pylori.
Login for details - Hereditary motor and sensory neuropathy. Oral vitamin C does not seem to improve neuropathy in these patients.
Login for details - Interferon-related retinopathy. Oral vitamin C does not seem to improve retinopathy associated with interferon therapy.
Login for details - Leukemia. Oral vitamin C does not seem to reduce the risk of leukemia or mortality from leukemia.
Login for details - Low birth weight. Oral vitamin C does not seem to reduce the risk of infants being born with a low birth weight.
Login for details - Lung cancer. Oral vitamin C does not seem to reduce the risk of lung cancer.
Login for details - Melanoma. Oral vitamin C does not seem to reduce the risk of melanoma.
Login for details - Miscarriage. Oral vitamin C does not seem to reduce the risk of miscarriage.
Login for details - Overall mortality. Oral vitamin C does not reduce overall mortality.
Login for details - Pancreatic cancer. Oral vitamin C does not seem to prevent pancreatic cancer.
Login for details - Pre-eclampsia. Oral vitamin C does not seem to prevent pre-eclampsia.
Login for details - Preterm labor. Oral vitamin C does not seem to prevent preterm labor.
Login for details - Prostate cancer. Oral vitamin C does not seem to prevent prostate cancer.
Login for details - Radiation dermatitis. Topical vitamin C does not seem to prevent radiation dermatitis in cancer patients.
Login for details - Sepsis. Intravenous vitamin C, alone or in combination with thiamine and/or hydrocortisone, does not seem to reduce mortality or prevent organ failure in sepsis or septic shock.
Login for details - Small for gestational age (SGA). Oral vitamin C does not seem to reduce SGA.
Login for details - Stillbirth. Oral vitamin C does not seem to prevent stillbirth.
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- Age-related macular degeneration (AMD). Oral vitamin C has only been evaluated in combination with other ingredients; its effect when used alone is unclear.
Login for details - Albuminuria. Oral vitamin C has only been evaluated in combination with other ingredients; its effect when used alone is unclear.
Login for details - Allergic rhinitis (hay fever). It is unclear if oral vitamin C is beneficial in patients with hay fever.
Login for details - Alzheimer disease. It is unclear if dietary vitamin C helps to prevent this condition.
Login for details - Amyotrophic lateral sclerosis (ALS, Lou Gehrig's disease). It is unclear if oral vitamin C helps to prevent ALS.
Login for details - Anthracycline cardiotoxicity. Login for details
- Aspirin-associated gastric damage. It is unclear if oral vitamin C helps to prevent gastric damage caused by aspirin.
Login for details - Athletic performance. It is unclear if oral vitamin C improves athletic performance.
Login for details - Atopic disease. It is unclear if dietary vitamin C helps to prevent atopic disease.
Login for details - Attention deficit-hyperactivity disorder (ADHD). Small clinical studies suggest that high-dose oral vitamin C may not improve symptoms in patients with ADHD.
Login for details - Autism spectrum disorder. It is unclear if oral vitamin C is beneficial in patients with autism spectrum disorder.
Login for details - Brain tumor. It is unclear if oral vitamin C helps to prevent brain tumors.
Login for details - Breast cancer. It is unclear if oral vitamin C helps to prevent breast cancer or breast cancer-related mortality.
Login for details - Burns. Small studies suggest that intravenous vitamin C may modestly improve symptoms in patients with severe burns.
Login for details - Cancer. It is unclear if oral or intravenous vitamin C helps to prevent cancer or cancer-related mortality.
Login for details - Cataracts. It is unclear if oral vitamin C helps to prevent cataracts.
Login for details - Cervical cancer. It is unclear if oral vitamin C helps to prevent cervical cancer.
Login for details - Chronic fatigue syndrome (CFS). Login for details
- Colistin-induced nephrotoxicity. It is unclear if intravenous vitamin C helps to prevent nephrotoxicity from colistin.
Login for details - Contrast induced nephropathy. It is unclear if oral vitamin C helps to prevent contrast-induced nephropathy (CIN).
Login for details - Coronary artery bypass graft (CABG) surgery. It is unclear if intravenous vitamin C helps to improve patient outcomes after CABG surgery.
Login for details - Delirium. Oral vitamin C has only been evaluated in combination with other ingredients; its effect when used alone is unclear.
Login for details - Dental plaque. It is unclear if vitamin C in a chewing gum helps to reduce dental plaque formation.
Login for details - Depression. It is unclear if oral vitamin C improves symptoms in patients with depression.
Login for details - Diabetes. It is unclear if oral vitamin C prevents diabetes. Some low-quality research suggests that vitamin C might improve glycemic control in patients with diabetes.
Login for details - Dry mouth. Oral vitamin C has only been evaluated in combination with vitamin E; its effect when used alone is unclear.
Login for details - Endometrial cancer. Increased dietary vitamin C has been linked to reduced risk of endometrial cancer.
Login for details - Endoscopy-associated adverse effects. It is unclear if a topical vitamin C spray reduces mucosal irritation in patients undergoing Lugol chromoendoscopy.
Login for details - Esophageal cancer. Oral vitamin C has only been evaluated in combination with other ingredients; its effect when used alone is unclear.
Login for details - Exercise-induced asthma. Small clinical studies suggest that oral vitamin C may modestly improve symptoms in patients with exercise-induced asthma.
Login for details - Exercise-induced muscle damage. It is unclear if oral vitamin C is beneficial in exercise-induced muscle damage.
Login for details - Gallbladder disease. It is unclear if oral vitamin C reduces the risk of gallbladder disease.
Login for details - Gastric cancer. It is unclear if dietary or supplemental vitamin C reduces the risk of gastric cancer.
Login for details - Gastritis. There is limited evidence on the oral use of vitamin C in omeprazole-induced corpus gastritis.
Login for details - Gout. It is unclear if oral vitamin C helps to prevent or manage gout.
Login for details - Hearing loss. There is limited evidence on the intravenous use of vitamin C in idiopathic sudden sensorineural hearing loss.
Login for details - Heart transplant complications. Oral vitamin C has only been evaluated in combination with other ingredients; its effect when used alone is unclear.
Login for details - HIV/AIDS. Oral vitamin C has only been evaluated in combination with other ingredients; its effect when used alone is unclear.
Login for details - HIV transmission. Oral vitamin C has only been evaluated in combination with other ingredients; its effect when used alone is unclear.
Login for details - Hyperphosphatemia. Intravenous vitamin C might be beneficial for reducing phosphate levels in patients with end-stage renal disease.
Login for details - Infertility. It is unclear if oral vitamin C is beneficial in anovulatory women.
Login for details - Nonalcoholic steatohepatitis (NASH). Oral vitamin C has only been evaluated in combination with other ingredients; its effect when used alone is unclear.
Login for details - Non-Hodgkin lymphoma. It is unclear if oral vitamin C reduces the risk of developing diffuse large B-cell lymphoma.
Login for details - Oral cancer. It is unclear if oral vitamin C reduces the risk of developing oral cancer.
Login for details - Oral leukoplakia. Oral vitamin C has only been evaluated in combination with other ingredients; its effect when used alone is unclear.
Login for details - Osteoarthritis. It is unclear if dietary vitamin C reduces the risk of developing osteoarthritis.
Login for details - Osteoporosis. It is unclear if dietary vitamin C improves bone density or reduces fracture risk in patients at risk for osteoporosis.
Login for details - Ovarian cancer. Dietary vitamin C might not affect the risk of ovarian cancer.
Login for details - Parkinson disease. Dietary vitamin C might not affect the risk of developing this condition.
Login for details - Periodontitis. Login for details
- Peripheral arterial disease (PAD). It is unclear if dietary vitamin C helps to reduce the risk of developing PAD.
Login for details - Physical performance. It is unclear if oral vitamin C helps to improve physical performance and muscle strength in older people.
Login for details - Pneumonia. It is unclear if oral vitamin C helps to prevent pneumonia.
Login for details - Postoperative recovery. It is unclear if oral or intravenous vitamin C improves postoperative recovery.
Login for details - Premature rupture of membranes (PROM). Oral vitamin C seems to reduce the risk of PROM in some women; however, the addition of oral vitamin E seems to negate any benefit.
Login for details - Pressure ulcers. It is unclear if oral vitamin C helps to reduce the risk of pressure ulcers.
Login for details - Radiation proctopathy. Oral vitamin C has only been evaluated in combination with vitamin E; its effect when used alone is unclear.
Login for details - Renal cell carcinoma. It is unclear if increased dietary intake of vitamin C helps to reduce the risk of renal cell carcinoma.
Login for details - Restless legs syndrome (RLS). It is unclear if oral vitamin C helps to reduce symptoms of stress.
Login for details - Sunburn. Topical and oral vitamin C has only been evaluated in combination with other ingredients; its effect when used alone is unclear.
Login for details - Stress. It is unclear if oral vitamin C helps to reduce symptoms of stress.
Login for details - Stroke. Observational research has found that although taking vitamin C supplements does not seem to be beneficial, eating more vitamin C-rich food is linked with reduced risk of stroke.
Login for details - Tetanus. It is unclear if intravenous vitamin C helps to reduce symptoms of tetanus.
Login for details - Urinary tract infections (UTIs). Login for details
- Vascular dementia. It is unclear if oral vitamin C reduces the risk of vascular dementia.
Login for details - Wound healing. It is unclear if oral vitamin C improves the healing of chronic foot ulcers.
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When taken by mouth: Vitamin C is likely safe for most people. In some people, vitamin C might cause side effects such as stomach cramps, nausea, heartburn, and headache. The chance of getting these side effects increases with higher doses. Taking more than 2000 mg daily is possibly unsafe and may cause kidney stones and severe diarrhea. In people who have had a kidney stone, taking amounts greater than 1000 mg daily increases the risk of getting more kidney stones.
When applied to the skin: Vitamin C is likely safe for most people.
Special Precautions & Warnings:
Pregnancy and breast-feeding: Vitamin C is likely safe to take by mouth during pregnancy in amounts no greater than 2000 mg daily for those 19 years and older and 1800 mg daily for those 14-18 years old. Taking too much vitamin C during pregnancy can cause problems for the newborn baby. Vitamin C is possibly unsafe when taken by mouth in excessive amounts.Infants and children: Vitamin C is likely safe when taken by mouth appropriately. Vitamin C is possibly unsafe when taken by mouth in amounts higher than 400 mg daily for children 1-3 years, 650 mg daily for children 4-8 years, 1200 mg daily for children 9-13 years, and 1800 mg daily for adolescents 14-18 years.
Alcohol use disorder: People who regularly use alcohol, especially those who have other illnesses, often have vitamin C deficiency. These people might need to be treated for a longer time than normal to restore vitamin C levels to normal.
Cancer: Cancerous cells collect high concentrations of vitamin C. Until more is known, only use high doses of vitamin C under the direction of your oncologist.
Chronic kidney disease: Long-term kidney disease might increase the risk of vitamin C deficiency. Vitamin C supplements might also increase the amount of oxalate in the urine in some people. Too much oxalate in the urine can increase the risk of kidney failure in people with kidney disease.
A metabolic deficiency called "glucose-6-phosphate dehydrogenase" (G6PD) deficiency: Large amounts of vitamin C can cause red blood cells to break in people with this condition. Avoid excessive amounts of vitamin C.
Kidney stones: Large amounts of vitamin C can increase the chance of getting kidney stones. Do not take vitamin C in amounts greater than those found in basic multivitamins.
Smoking and chewing tobacco: Smoking and chewing tobacco lowers vitamin C levels. People who smoke or chew tobacco should consume more vitamin C in the diet.
Acetaminophen (Tylenol, others)
Interaction Rating=Minor Be watchful with this combination.
The body breaks down acetaminophen (Tylenol, others) to get rid of it. Large amounts of vitamin C can decrease how quickly the body breaks down acetaminophen. It is not clear exactly when or if this interaction is a big concern.
Aluminum
Interaction Rating=Moderate Be cautious with this combination.
Aluminum is found in most antacids. Vitamin C can increase how much aluminum the body absorbs. But it isn't clear if this interaction is a big concern. Take vitamin C two hours before or four hours after antacids.
Aspirin
Interaction Rating=Minor Be watchful with this combination.
The body breaks down aspirin to get rid of it. Large amounts of vitamin C might decrease the breakdown of aspirin. Decreasing the breakdown of aspirin might increase the effects and side effects of aspirin. Do not take large amounts of vitamin C if you take large amounts of aspirin.
Choline Magnesium Trisalicylate (Trilisate)
Interaction Rating=Minor Be watchful with this combination.
Vitamin C might decrease how quickly the body gets rid of choline magnesium trisalicylate (Trilisate). But it is not clear if this interaction is a big concern.
Estrogens
Interaction Rating=Moderate Be cautious with this combination.
The body breaks down estrogens to get rid of them. Vitamin C might decrease how quickly the body gets rid of estrogens. Taking vitamin C along with estrogens might increase the effects and side effects of estrogens.
Fluphenazine (Prolixin)
Interaction Rating=Moderate Be cautious with this combination.
Large amounts of vitamin C might decrease how much fluphenazine (Prolixin) is in the body. Taking vitamin C along with fluphenazine (Prolixin) might decrease the effectiveness of fluphenazine (Prolixin).
Medications for cancer (Chemotherapy)
Interaction Rating=Moderate Be cautious with this combination.
Vitamin C is an antioxidant. There is some concern that antioxidants might decrease the effectiveness of some medications used for cancers. But it is too soon to know if this interaction occurs.
Medications used for HIV/AIDS (Protease Inhibitors)
Interaction Rating=Moderate Be cautious with this combination.
Taking large doses of vitamin C might reduce how much of some medications used for HIV/AIDS stays in the body. This could decrease the effectiveness of some medications used for HIV/AIDS.
Some of these medications used for HIV/AIDS include amprenavir (Agenerase), nelfinavir (Viracept), ritonavir (Norvir), and saquinavir (Fortovase, Invirase).
Medications used for lowering cholesterol (Statins)
Interaction Rating=Moderate Be cautious with this combination.
Taking vitamin C, beta-carotene, selenium, and vitamin E together might decrease the effectiveness of some medications used for lowering cholesterol. It is not known if vitamin C alone decreases the effectiveness of some medications used for lowering cholesterol.Some medications used for lowering cholesterol include atorvastatin (Lipitor), fluvastatin (Lescol), lovastatin (Mevacor), and pravastatin (Pravachol).
Niacin
Interaction Rating=Moderate Be cautious with this combination.
Taking vitamin C along with vitamin E, beta-carotene, and selenium might decrease some of the helpful effects of niacin. Niacin can increase the good cholesterol. Taking vitamin C along with these other vitamins might decrease the effectiveness of niacin for increasing good cholesterol.
Nicardipine (Cardene)
Interaction Rating=Minor Be watchful with this combination.
Vitamin C is taken up by cells. Taking nicardipine (Cardene) along with vitamin C might decrease how much vitamin C is taken in by cells. The significance of this interaction is not clear.
Nifedipine
Interaction Rating=Minor Be watchful with this combination.
Vitamin C is taken up by cells. Taking nifedipine (Adalat, Procardia) along with vitamin C might decrease how much vitamin C is taken in by cells. The significance of this interaction is not clear.
Salsalate (Disalcid)
Interaction Rating=Minor Be watchful with this combination.
Vitamin C might decrease how quickly the body gets rid of salsalate (Disalcid). Taking vitamin C along with salsalate (Disalcid) might cause too much salsalate (Disalcid) in the body, and increase the effects and side effects of salsalate.
Warfarin (Coumadin)
Interaction Rating=Moderate Be cautious with this combination.
Warfarin (Coumadin) is used to slow blood clotting. Large amounts of vitamin C might decrease the effectiveness of warfarin (Coumadin). Decreasing the effectiveness of warfarin (Coumadin) might increase the risk of clotting. Be sure to have your blood checked regularly. The dose of your warfarin (Coumadin) might need to be changed.
Acerola: Acerola contains high levels of vitamin C. Don't take large amounts of acerola along with vitamin C. This might give you too much vitamin C. Adults should not take more than 2000 mg vitamin C per day.
Chromium: Vitamin C might increase chromium absorption. Don't take large doses of chromium and vitamin C together. It isn't known whether separating the doses by several hours avoids this interaction.
Copper: High doses of vitamin C (1500 mg daily) can decrease copper levels in the blood. This interaction probably isn't important except in people whose dietary intake of copper is low.
Grape: Taking vitamin C with grape seed might increase blood pressure in people with high blood pressure. It's not clear why this happens.
Iron: Vitamin C increases the absorption of iron when taken at the same time. But taking a vitamin C supplement to improve absorption of iron from the diet or from supplements probably isn't necessary for most people.
Rose hip: Rose hip contains high levels of vitamin C. Don't take large amounts of rose hip along with vitamin C. This might give you too much vitamin C. Adults should not take more than 2000 mg vitamin C per day.
Vitamin B12: There have been concerns that vitamin C can lower vitamin B12 levels in the body. But vitamin C supplements don't seem to affect levels of vitamin B12.
There are no known interactions with foods.
Vitamin C is an important nutrient. Fresh fruits and vegetables, especially citrus fruits, are good sources of vitamin C. The amount that should be consumed on a daily basis is called the recommended dietary allowance (RDA). For adult males, the RDA is 90 mg daily. For females 19 years and older, the RDA is 75 mg daily. While pregnant and breastfeeding, the RDA is 120 mg daily for people 19-50 years old. In children, the RDA depends on age.
Vitamin C is also available in supplements, combination products, lotions, creams, serums, sprays, and patches. Supplements have been used safely by adults in doses up to 2000 mg daily. Speak with a healthcare provider to find out what type of product and dose might be best for a specific condition.
Acide Ascorbique, Acide Cévitamique, Acide Iso-Ascorbique, Acide L-Ascorbique, Acido Ascorbico, Antiscorbutic Vitamin, Ascorbate, Ascorbate de Calcium, Ascorbate de Sodium, Ascorbic Acid, Ascorbic acid, Ascorbyl Palmitate, Calcium Ascorbate, Cevitamic Acid, Iso-Ascorbic Acid, L-Ascorbic Acid, Magnesium Ascorbate, Palmitate d'Ascorbyl, Selenium Ascorbate, Sodium Ascorbate, Vitamina C, Vitamine Antiscorbutique, Vitamine C.
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