We found no evidence to support antioxidant supplements for primary or secondary prevention. Beta-carotene and vitamin E seem to increase mortality, and so may higher doses of vitamin A. Antioxidant supplements need to be considered as medicinal products and should undergo sufficient evaluation before marketing.
Oral antioxidant supplementation for fatigue associated with primary biliary cirrhosis: results of a multicentre, randomized, placebo-controlled, cross-over trial.
We have previously reported, in an uncontrolled trial, an improvement in fatigue scores in patients with primary biliary cirrhosis given oral antioxidant supplementation. We now present data from a controlled trial.
                Sixty-one patients with primary biliary cirrhosis-associated fatigue were randomized into a double-blind, placebo-controlled, cross-over trial. Participants received 12 weeks each of placebo and antioxidant supplementation (vitamins A, C and E, selenium, methionine and ubiquinone) in random order, separated by a 4-week washout period. The primary trial outcome (fatigue) was assessed using the Fisk scale. Other symptoms of primary biliary cirrhosis were measured using Likert and visual analogue scales.
                Forty-four patients completed both arms of the trial. No significant changes in fatigue were recorded in the active phase of treatment (median improvement in Fisk score, 1; P = 0.61). Small improvements in Fisk scores were recorded during placebo therapy (median improvement, 4; P = 0.03). Neither medication was associated with improvement in any other symptoms related to primary biliary cirrhosis. Adverse effects were more common during active therapy and were mild and self-limiting. One patient died from unrelated causes during active treatment.
                Although oral antioxidant supplementation appears to be safe, we could not find any evidence for a beneficial effect on fatigue or other liver-related symptoms.