First Do No Harm: a guide to choosing wisely in general practice

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Vitamin C infusions

First Do No Harm: a guide to choosing wisely in general practice
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Last revised: 01 Nov 2022

Information sheet for patients

Is this information for you?

This information sheet is for you if you are considering vitamin C infusions for any reason.

Vitamin C is an essential nutrient that normally only comes from food. It plays an important role in the nervous system and other functions, including the healing of wounds and energy metabolism.

Because vitamin C is found in foods such as citrus fruits (for example, oranges and grapefruit) and vegetables,1 most people in Australia get more than enough vitamin C in their regular diet.

Having no vitamin C for months or years leads to scurvy, which results in:2

  • weakness
  • severe joint and leg pain
  • bleeding gums
  • bruising.

In the past, sailors sometimes developed scurvy because they didn’t have fresh food for months at a time, but it is now very rare.

Some people have suggested that vitamin C is a possible treatment for cancer, sepsis (severe infection) and COVID-19, but there is no evidence that vitamin C infusions deliver any health benefits.

In line with guidelines from Ƶ (RACGP), your general practitioner (GP) will only recommend treatments that are well grounded in scientific evidence.

Several research studies3–7 have tested vitamin C infusions to find out if it is an effective treatment, but found that vitamin C infusions do not seem to provide health benefits for any condition.

In fact, vitamin C infusion is dangerous for some people with kidney disease, particularly those with, or at risk of:

  • kidney stones1
  • haemochromatosis8
  • glucose-6-phosphate dehydrogenase (G6PD) deficiency.9

Is there evidence that vitamin C infusions benefit patients with cancer?

There is no evidence to prove that vitamin C infusions make tumours smaller or stop them from growing.

Is there evidence that vitamin C infusions help patients with COVID-19?

No high-quality studies have shown that vitamin C infusions provide any benefits to patients with COVID-19.5 This is confirmed by the Therapeutic Goods Administration (an Australian Government agency), which issued a statement saying there was no evidence to support the use of vitamin C infusions to treat COVID-19.10

What are the side effects of vitamin C infusions?

The most common side effects are:8

  • temporary nausea
  • vomiting
  • headache
  • discomfort at the injection site.

Although most of these side effects are mild, it is important to know that:

  • some people with a kidney disease who had vitamin C infusions developed kidney stones and their kidney function got worse8,9
  • if you have G6PD deficiency, you should not have vitamin C infusions, as they could cause a breakdown of your red blood cells1,8
  • if you have haemochromatosis, you should not have vitamin C infusions, as they could result in more iron-induced tissue damage.1

Does vitamin C affect cancer treatments?

There are a number of ways in which vitamin C could negatively affect cancer treatments. If you are a cancer patient and you are considering a vitamin C infusion, you should discuss this with your cancer specialist (oncologist).11,12

If you are being treated for multiple myeloma with bortezomib, you should not have a vitamin C infusion, as it may reduce the effectiveness of bortezomib.      

Is there a recommended dose and duration of vitamin C infusions?

As current guidelines do not recommend vitamin C infusion for any condition, there is no consensus about the optimal doses, frequency or duration of intravenous vitamin C therapy.13–15

Are vitamin C infusions covered by Medicare?

No, you will have to pay for any vitamin C infusions you have.

Based on the available research and evidence, the RACGP does not recommend the use of vitamin C infusions.

We do recommend that you always eat a healthy diet that includes lots of fresh fruit and vegetables. This will provide you with adequate vitamin C, which is essential for your general good health.

  • Chapman K, ,
  • National Cancer Institute (US),  
  • Therapeutic Goods Administration,

If you still want to go ahead

·         If you want to have a vitamin C infusion, tell your treating doctors, so you can discuss the potential risks and harms.

  • If you have haemochromatosis, kidney disease or G6PD deficiency, we strongly recommend that you do not have a vitamin C infusion.
  • If you are being treated for cancer, we strongly recommend that you talk with your oncologist about how vitamin C might affect your current and proposed treatments.
  • Before you have a vitamin C infusion, arrange a kidney function blood test and a screening for G6PD deficiency.8
  1. [Accessed 30 March 2022].
  2. [Accessed 6 April 2022]
  3. Wei XB, Wang ZH, Liao XL, et al. Efficacy of vitamin C in patients with sepsis: An updated meta-analysis. Eur J Pharmacol 2020;5(868):172889. [Accessed 6 April 2022].
  4. Fowler AA, Truwit JD, Hite RD, et al. Effect of vitamin C infusion on organ failure and biomarkers of inflammation and vascular injury in patients with sepsis and severe acute respiratory failure: The CITRIS-ALI randomized clinical trial. JAMA 2019;322(13):1261–70. [Accessed 6 April 2022].
  5. [version 57]. National COVID-19 Clinical Evidence Taskforce, 2022 [Accessed 26 October 2022].
  6. Hoppe C, Freuding M, Büntzel J, Münstedt K, Hübner J. Clinical efficacy and safety of oral and intravenous vitamin C use in patients with malignant diseases. J Cancer Res Clin Oncol 2021;147(10):3025–42. [version 57]. National COVID-19 Clinical Evidence Taskforce, 2022 [Accessed 26 October 2022].
  7. Kim MS, Kim DJ, Na CH, Shin BS. A study of intravenous administration of vitamin C in the treatment of acute herpetic pain and postherpetic neuralgia. Ann Dermatol 2016;28(6):677. [version 57]. National COVID-9 Clinical Evidence Taskforce, 2022 [Accessed 26 October 2022].
  8. Bazzan AJ, Zabrecky G, Wintering N, Newberg AB, Monti DA. Retrospective evaluation of clinical experience with intravenous ascorbic acid in patients with cancer. Integr Cancer Ther 2018;17(3):912–20. [version 57]. National COVID19 Clinical Evidence Taskforce, 2022 [Accessed 26 October 2022].
  9. Carr AC, Cook J. Intravenous vitamin c for cancer therapy – Identifying the current gaps in our knowledge. Front Physiol 2018;23(9):1182. [version 57]. National COVID-19 Clinical Evidence Taskforce, 2022 [Accessed 26 October 2022].
  11. [Accessed 1 April 2022].
  12. Perrone G, Hideshima T, Ikeda H, et al. Ascorbic acid inhibits antitumor activity of bortezomib in vivo. Leukemia 2009;23(9):1679–86. [Accessed 1 April 2022].
  13. Monti DA, Bazzan AJ, Zabrecky G, Newberg AB. Brief report: Stability and chemical characteristics of injectable ascorbic acid for patients with cancer. Altern Ther Health Med 2019;25(2):42–45. [Accessed 1 April 2022].
  14. Vissers MCM, Das AB. Potential mechanisms of action for vitamin C in cancer: Reviewing the evidence. Front hysiol 2018;3(9):809. [Accessed 1 April 2022].
  15. Walker SE, Iazzetta J, Law S, et al. Administration of intravenous ascorbic acid – Practical considerations for clinicians. Nutrients 2019;11(9):1994. [Accessed 1 April 2022].
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