Vitamin C improves healing of foot ulcers: a randomised, double-blind, placebo-controlled trial

Br J Nutr. 2021 Nov 28;126(10):1451-1458. doi: 10.1017/S0007114520003815. Epub 2020 Sep 28.

Abstract

Chronic foot ulcers are associated with a high risk of osteomyelitis, poor quality of life, amputations and disability. Few strategies improve their healing, and amputation rates in high-risk foot services are usually over 30 %. We conducted a randomised, inactive-placebo controlled, double-blind trial of 500 mg of slow-release vitamin C in sixteen people with foot ulcers in the Foot Wound Clinic at Westmead Hospital. Nine were randomised to control and seven to vitamin C. When serum vitamin C results become available at 4 weeks, all people with deficiency were offered both vitamin C and glucosamine tablets for the next 4 weeks. Patients without baseline deficiency continued their original assigned treatment. The primary outcome was percentage ulcer healing (reduction in ulcer size) at 8 weeks. Fifty percentage of subjects had baseline vitamin C deficiency, half having undetectable levels. Healing at 8 weeks was significantly better in the vitamin C group (median 100 v. -14 %, P = 0·041). Healing without amputation occurred in all patients in the vitamin C group. In contrast, 44 % of controls had not healed their ulcer at the end of the study period. Vitamin C improved healing of foot ulcers. Further studies are needed to determine whether there is a threshold effect for serum vitamin C above which therapy is ineffective and whether there are better or lesser responding subgroups. Because of its low cost and ease of access and administration, we recommend offering vitamin C therapy to all people who have chronic foot ulcers and potentially suboptimal vitamin C intake. Trial registration number: ACTRN12617001142325.

Keywords: Amputation; Diabetes; Foot ulcer; Ulcer healing; Vascular disease; Vitamin C.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Ascorbic Acid / therapeutic use*
  • Diabetic Foot* / drug therapy
  • Humans
  • Ulcer / drug therapy
  • Vitamins / therapeutic use
  • Wound Healing*

Substances

  • Vitamins
  • Ascorbic Acid