Vitamin C

Vitamin C

PEP Topic 

Vitamin C is a water-soluble vitamin that cannot be made by the body and must be obtained from foods or other sources. It is found in abundance in citrus fruits, such as oranges, grapefruit, and lemons, and in green leafy vegetables, potatoes, strawberries, bell peppers, and cantaloupe. The scientific/medical name is ascorbic acid or ascorbate. Vitamin C supplements are available in powder or chewable pill form. Vitamin C is known to be an antioxidant blocking the action of free radicals that can damage cells and is an important component of intracellular matrices and connective tissue. Vitamin C supplements have been tested as an intervention for diarrhea and fatigue in patients with cancer. Topical vitamin C has been studied in patients with cancer for effectiveness in the prevention and treatment of radiodermatitis.

Effectiveness Not Established

Research Evidence Summaries

Halperin, E.D., Gaspar, L., George, S., Darr, D., & Pinnell, S. (1993). A double-blind, randomized, prospective trial to evaluate topical vitamin C solution for the prevention of radiation dermatitis. International Journal of Radiation Oncology, Biology, Physics, 26, 413–416.

doi: 10.1016/0360-3016(93)90958-X

Study Purpose:

To ascertain the value of topical ascorbic acid solution (ASC) in prevention of radiation dermatitis

Intervention Characteristics/Basic Study Process:

Exactly half of the patients (42) were randomized to ASC solution on left side of head with control lotion on right and the other half (42) were randomized to the reverse. At initiation of radiotherapy (RT), patients applied topical solutions (10% aqueous solution of L-ascorbic acid [L-ASC] and vehicle), twice per day prior to and throughout the course of RT, to left and right sides of the head.

Radiotherapist, principal investigator, supervising nurses, and patients were blinded as to the contents of the solutions.

Sample Characteristics:

  • The sample size was 65 participants with a diagnosed primary brain tumor with cancer metastatic to the brain (median age = 49 years; age range = 1–76 years).
  • The sample included 43 men and 41 women
  • The dose of radiation ranged from 14–70.3 Gy (median = 50 Gy).


The study was held at Duke University but included 10 cases from two United Kingdom facilities.

Study Design:

This was a quasiexperimental, double-blinded study; patients were used as their own controls.

Measurement Instruments/Methods:

Skin scores were done in accordance with the skin reaction criteria adopted by the RT committee of the CNS Cancer Consortium.


  • Ten patients (15%) preferred ascorbic acid.
  • Twenty patients (31%) preferred the placebo.
  • Thirty-five (54%) preferred neither.


No discernible benefit exists to ascorbic acid lotion in the manner in which it was used in this trial for the prevention of radiation dermatitis.


  • Twenty patients were entered in the trial but were not evaluable, and reasons for exclusion were not discussed.
  • Likely differences in skin responses based on age were not examined and reported. The study included a wide range of ages.
  • The study had a relatively small sample size.