Taking high doses of vitamin E supplements can increase the risk of lung cancer, research suggests.
The US study of 77,000 people found taking 400 milligrams per day long-term increased cancer risk by 28% – with smokers at particular risk.
The researchers followed people aged between 50 and 76 for four years and looked at their average daily use of vitamin C and folic acid, and vitamin E supplements.
It follows warnings about similar risks of excessive beta-carotene use.
An expert said people should get their vitamins from fruit and vegetables.
Vitamin E is known to be an antioxidant – protecting cells from molecules called free radicals. However, if taken in large doses, it can damage cells.