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 500mg of slow-release vitamin C in 16 people with foot ulcers conducted in the foot-wound clinic at Westmead Hospital. Nine were randomised to control and 7 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 percent ulcer healing (reduction in ulcer size) at 8 weeks.
Fifty percent 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% versus –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.