A Cochrane review included 6 small studies (range 10 to 40 patients) with a total of 183 subjects. 4 studies considered people with venous ulcers, 1 study arterial ulcers and 1 people with mixed ulcers. Oral zinc sulphate compared with placebo in people with venous ulcers showed no statistically significant difference (RR 1.22, 95% CI 0.88 to 1.68; 4 studies, n=141). Overall there is no evidence of a beneficial effect of treatment with zinc sulphate on the number of ulcers healed.
Comment: The quality of evidence is downgraded by imprecise results (limited study size for each comparison), by limitations in study quality, and by inconsistency (heterogeneity in interventions and follow-up).