The study conducted by University of Colorado Denver suggested that over-the-counter supplements may actually increase cancer risk if taken in excess of the recommended daily amount.
Tim Byers, associate director for cancer prevention and control at the CU Cancer Center asserted that they were not sure why this was happening at the molecular level but evidence showed that people who take more dietary supplements than needed tend to have a higher risk of developing cancer.
One trial exploring the effects of beta-keratin supplements showed that taking more than the recommended dosage increased the risk for developing both lung cancer and heart disease by 20 percent. Folic acid, which was thought to help reduce the number of polyps in a colon, actually increased the number in another trial.
Byers asserted that when they first tested dietary supplements in animal models they found that the results were promising and eventually they were able to move on to the human populations.
He continued that people can get the daily recommended doses of vitamins and minerals in their diets by eating healthy meal and that many adults who take vitamin supplements may not need them.
Byers concluded that at the end of the day they have discovered that taking extra vitamins and minerals did more harm than good.