Vitamin C

What is vitamin C used for?

Updated 3 Nov 2026

Short answer

Its clearest use is to prevent and treat scurvy, the disease of vitamin C deficiency.[1] For immune support, taking at least 200 mg every day made colds 8% shorter in adults and 14% shorter in children.[2] For heart and circulation, short trials found that it lowered systolic blood pressure by about 4 mmHg and improved the function of blood vessels.[3][4] It also helps the gut absorb iron from plant foods.[1] Large trials of 500 mg a day for 8 and 9.4 years found no fewer heart attacks or strokes.[5][6]

Sources (6)

  1. Vitamin C: Fact Sheet for Health Professionals. NIH Office of Dietary Supplements. ods.od.nih.gov
  2. Vitamin C for preventing and treating the common cold. Hemilä H, Chalker E Cochrane Database Syst Rev, 2013. PMID 23440782
  3. Effects of vitamin C supplementation on blood pressure: a meta-analysis of randomized controlled trials. Juraschek SP, Guallar E, Appel LJ, Miller ER 3rd Am J Clin Nutr, 2012. PMID 22492364
  4. Effect of vitamin C on endothelial function in health and disease: a systematic review and meta-analysis of randomised controlled trials. Ashor AW, Lara J, Mathers JC, Siervo M Atherosclerosis, 2014. PMID 24792921
  5. Vitamins E and C in the prevention of cardiovascular disease in men: the Physicians' Health Study II randomized controlled trial. Sesso HD, Buring JE, Christen WG, Kurth T, Belanger C, MacFadyen J, et al. JAMA, 2008. PMID 18997197
  6. A randomized factorial trial of vitamins C and E and beta carotene in the secondary prevention of cardiovascular events in women: results from the Women's Antioxidant Cardiovascular Study. Cook NR, Albert CM, Gaziano JM, Zaharris E, MacFadyen J, Danielson E, et al. Arch Intern Med, 2007. PMID 17698683

More about vitamin c

What is vitamin C?How much vitamin C do you need a day?What are the signs of vitamin C deficiency?Is vitamin C safe?Does vitamin C prevent or shorten colds?Does vitamin C lower blood pressure?

For education; not medical advice. Talk to a doctor before you start, stop or change a supplement.