Professor Brian Ratcliffe from Robert Gordon University, in Aberdeen, says that million of consumers are wasting their time and money by taking vitamin supplements.
"I couldn't tell you what my personal biological requirement is for any vitamin. All I can do is use the population-based evidence," he said in a speech at the British Festival of Science at the University of Surrey in Guildford.
He added that consuming many vitamins could easily increase their levels in the body and can prove dangerous. For example excess levels of vitamin A can lead to headaches and nausea and even osteoporosis.