Introduction
Vitamin C is found in citrus fruits, sweet peppers, and broccoli. The body uses vitamin C to make important tissues. Vitamin C has been used to help the body fight off illness, improve heart health, and strengthen bones. It is effective for treating scurvy (vitamin C deficiency).
It can be taken as a pill or powder. It can also be applied to the skin. Vitamin C can also be injected into the muscle and bloodstream by a healthcare provider.
Dosages
75 milligrams per day for adult men and 90 milligrams per day for adult women
What Research Shows
Likely Effective
- Alzheimer Disease —likely to lower risk C1
- Complex regional pain syndrome—likely to lower risk I1-I3
- Heart surgery support—likely to prevent atrial fibrillation M1-M3
- High blood pressure —likely to lower blood pressure in the short-term N1
- Stroke —likely to lower risk S1
- Upper respiratory tract infection in children —likely to reduce duration of illness T1
May Be Effective
May Not Be Effective
- Age-related macular degeneration—may not prevent or delay onset B1
- Cardiovascular disease —may not lower risk E1, E2
- Cognitive function—may not provide benefit G1-G3
- Diabetic kidney disease—may improve early kidney damage K1
- Female subfertility—may not provide benefit L1
- Lipid profile —may not change profile O1
- Miscarriage—may not prevent P1
- Pregnancy support —may not provide benefit R1-R3
Not Enough Data to Assess
Editorial process and description of evidence categories can be found at EBSCO NAT Editorial Process.
Editorial process and description of evidence categories can be found at EBSCO NAT Editorial Process.
Safety Notes
It is likely safe to take vitamin C in small doses for a short time. Large doses may not be safe. Not enough studies have been done to say whether it is safe to take for a long period. Women who are pregnant or breastfeeding should not take large doses of vitamin C.
Interactions
Talk to your doctor about any supplements or therapy you would like to use. Some can interfere with treatment or make conditions worse.
References
REFA Age-Related Cataract
REFA1 Mathew MC, Ervin AM, et al. Antioxidant vitamin supplementation for preventing and slowing the progression of age-related cataract. Cochrane Database Syst Rev. 2012 Jun 13;(6):CD004567.
REFA2 Wei L, Liang G, et al. Association of vitamin C with the risk of age-related cataract: a meta-analysis. Acta Ophthalmol. 2016 May;94(3):e170-176.
REFB Age-Related Macular Degeneration
REFB1 Evans JR, Lawrenson JG. Antioxidant vitamin and mineral supplements for preventing age-related macular degeneration. Cochrane Database Syst Rev. 2017 Jul 30;7:CD000253.
REFC Alzheimer Disease
REFC1 Li FJ, Shen L, et al. Dietary intakes of vitamin E, vitamin C, and β-carotene and risk of Alzheimer's disease: a meta-analysis. J Alzheimers Dis. 2012;31(2):253-258.
REFD Asthma
REFD1 Milan SJ, Hart A, et al. Vitamin C for asthma and exercise-induced bronchoconstriction. Cochrane Database Syst Rev. 2013;(10):CD010391.
REFE Cardiovascular Disease
REFE1 Sesso HD, Buring JE, et al. Vitamins E and C in the prevention of cardiovascular disease in men: the Physicians’ Health Study II randomized controlled trial. JAMA. 2008;200(18):2123-2133.
REFE2 Al-Khudairy L, Flowers N, et al. Vitamin C supplementation for the primary prevention of cardiovascular disease. Cochrane Database Syst Rev. 2017 Mar 16;3:CD011114.
REFF Chronic Gout
REFF1 Andrés M, Sivera F, et al. Dietary supplements for chronic gout. Cochrane Database Syst Rev. 2014 Oct 7;(10):CD010156.
REFG Cognitive Function
REFG1 Butler M, Nelson VA, et al. Over-the-Counter Supplement Interventions to Prevent Cognitive Decline, Mild Cognitive Impairment, and Clinical Alzheimer-Type Dementia: A Systematic Review. Ann Intern Med. 2018 Jan 2;168(1):52-62.
REFG2 McCleery J, Abraham RP, et al. Vitamin and mineral supplementation for preventing dementia or delaying cognitive decline in people with mild cognitive impairment. Cochrane Database Syst Rev. 2018 Nov 1;11:CD011905.
REFG3 Rutjes AW, Denton DA, et al. Vitamin and mineral supplementation for maintaining cognitive function in cognitively healthy people in mid and late life. Cochrane Database Syst Rev. 2018 Dec 17;12:CD011906.
REFH Common Cold
REFH1 Hemilä H, Chalker E. Vitamin C for preventing and treating the common cold. Cochrane Database Syst Rev. 2013;(1):CD000980.
REFH2 Ran L, Zhao W, et al. Extra Dose of Vitamin C Based on a Daily Supplementation Shortens the Common Cold: A Meta-Analysis of 9 randomized controlled trials. Biomed Res Int. 2018:1837834.
REFH3 Gómez E, Quidel S, et al. Does vitamin C prevent the common cold? Medwave. 2018;18(4):e7235.
REFH4 Quidel S, Gómez E, et al. What are the effects of vitamin C on the duration and severity of the common cold? Medwave. 2018;18(6):e7261.
REFI Complex Regional Pain Syndrome
REFI1 Zillinger PE, Tuinerbrejjer WE, et al. Can vitamin C prevent complex regional pain syndrome in patients with wrist fractures? A randomized, controlled, multicenter dose-dependent study. J Bone Joint Surg Am. 2007;89(7):1424-1431.
REFI2 Chen S, Roffey DM, et al. Effect of Perioperative Vitamin C Supplementation on Postoperative Pain and the Incidence of Chronic Regional Pain Syndrome: A Systematic Review and Meta-Analysis. Clin J Pain. 2016 Feb;32(2):179-185.
REFI3 Aïm F, Klouche S, et al. Efficacy of vitamin C in preventing complex regional pain syndrome after wrist fracture: A systematic review and meta-analysis. Orthop Traumatol Surg Res. 2017 May;103(3):465-470.
REFJ Diabetes
REFJ1 Tabatabaei-Malazy O, Nikfar S, et al. Influence of ascorbic acid supplementation on type 2 diabetes mellitus in observational and randomized controlled trials; a systematic review with meta-analysis. J Pharm Pharm Sci. 2014;17(4):554-582.
REFJ2 Khodaeian M, Tabatabaei-Malazy O, et al. Effect of vitamins C and E on insulin resistance in diabetes: a meta-analysis study. Eur J Clin Invest. 2015 Nov;45(11):1161-1174.
REFJ3 Ashor AW, Werner AD, et al. Effects of vitamin C supplementation on glycaemic control: a systematic review and meta-analysis of randomised controlled trials. Eur J Clin Nutr. 2017;71(12):1371-1380.
REFK Diabetic Kidney Disease
REFK1 Bolignano D, Cernaro V, et al. Antioxidant agents for delaying diabetic kidney disease progression: A systematic review and meta-analysis. PLoS One. 2017 Jun 1;12(6):e0178699.
REFL Female Subfertility
REFL1 Showell MG, Mackenzie-Proctor R, et al. Antioxidants for female subfertility. Cochrane Database Syst Rev. 2017 Jul 28;7:CD007807.
REFM Heart Surgery Support
REFM1 Hemilä H, Suonsyrjä T. Vitamin C for preventing atrial fibrillation in high risk patients: a systematic review and meta-analysis. BMC Cardiovasc Disord. 2017;17(1):10.
REFM2 Hu X, Yuan L, et al. Efficacy and safety of vitamin C for atrial fibrillation after cardiac surgery: A meta-analysis with trial sequential analysis of randomized controlled trials. Int J Surg. 2017 Jan;37:58-64.
REFM3 Shi R, Li ZH, et al. Sole and combined vitamin C supplementation can prevent postoperative atrial fibrillation after cardiac surgery: A systematic review and meta-analysis of randomized controlled trials. Clin Cardiol. 2018;41(6):871-878.
REFN High Blood Pressure
REFN1 Juraschek SP, Guallar E, et al. Effects of vitamin C supplementation on blood pressure: a meta-analysis of randomized controlled trials. Am J Clin Nutr.2012;95(5):1079-1088.
REFO Lipid Profile
REFO1 Ashor AW, Siervo M, et al. Systematic review and meta-analysis of randomised controlled trials testing the effects of vitamin C supplementation on blood lipids. Clin Nutr. 2016 Jun;35(3):626-637.
REFP Miscarriage
REFP1 Balogun OO, da Silva Lopes K, et al. Vitamin supplementation for preventing miscarriage. Cochrane Database Syst Rev. 2016 May 6;(5):CD004073.
REFQ Pneumonia
REFQ1 Hemilä H, Louhiala P. Vitamin C for preventing and treating pneumonia. Cochrane Database Syst Rev. 2013 Aug 8;(8):CD005532.
DEFR Pregnancy Support
REFR1 Swaney P, Thorp J, et al. Vitamin C supplementation in pregnancy--does it decrease rates of preterm birth? A systematic review. Am J Perinatol. 2014 Feb;31(2):91-98.
REFR2 Rumbold A, Ota E, et al. Vitamin C supplementation in pregnancy. Cochrane Database Syst Rev. 2015;(9):CD004072.
REFR3 Zhou K, West HM, et al. Interventions for leg cramps in pregnancy. Cochrane Database Syst Rev. 2015 Aug 11;(8):CD010655.
REFS Stroke
REFS1 Chen GC, Lu DB, et al. Vitamin C intake, circulating vitamin C and risk of stroke: a meta-analysis of prospective studies. J Am Heart Assoc. 2013 Nov 27;2(6):e000329.
REFT Upper Respiratory Tract Infection in Children
REFT1 Vorilhon P, Arpajou B, et al. Efficacy of vitamin C for the prevention and treatment of upper respiratory tract infection. A meta-analysis in children. Eur J Clin Pharmacol. 2019 Mar;75(3):303-311.
REFU Urinary Tract Infections in Pregnancy
REFU1 Ghouri F, Hollywood A, et al. A systematic review of non-antibiotic measures for the prevention of urinary tract infections in pregnancy. BMC Pregnancy Childbirth. 2018 Apr 13;18(1):99.