Oral zinc supplementation improves hepatic encephalopathy. Results of a randomised controlled trial

22 cirrhotic patients with chronic encephalopathy were given oral zinc supplementation or placebo in a double-blind randomised trial. In the group which received zinc acetate 600 mg a day for 7 days, serum zinc had been restored to normal by day 8. On day 8 hepatic encephalopathy, as assessed by a trailmaking test, was improved in the supplemented group but not in the placebo group. There was also a significant increase in blood urea nitrogen in the supplemented group. Short-term oral zinc supplementation probably improved hepatic encephalopathy by correcting the zinc deficiency that compromises conversion of ammonia to urea. The duration of this improvement requires further investigation.