Every day millions of people in the world take vitamin supplements. It is an industry that is worth millions a year, but the pills are surrounded by controversy. Some people claim that by taking them in large doses, they will prevent or even cure illnesses like cancer and heart disease. But others fear that taking large doses of some vitamins could in certain cases be dangerous.
For most people there’s absolutely no benefit in taking high dose vitamin supplements, said Catherine Collins, chief dietician at London’s St George Hospital. At best they are a waste of money and at worst they could seriously affect your health.