Many take vitamins to stay fit and healthy but intake of them more than the recommended daily amount will increase the risk of cancer and heart disease by 20%, according to a new study.

Tim Byers, a professor at the University of Colorado Cancer Centre who led the study said, "We are not sure why this is happening at the molecular level, but evidence shows that people who take more dietary supplements than needed tend to have a higher risk of developing cancer."

The researchers wanted to explore whether the cancer risk is reduced if the intake of extra vitamins is stopped. The line of research started 20 years ago with the observation that people who ate more fruits and vegetables tended to have less cancer. When it was first tested on animal models the results were promising as per the study reports. "Eventually we were able to move on to the human populations. We studied thousands of patients for ten years who were taking dietary supplements and placebos."

Based on their findings, researchers concluded that the supplements were not beneficial for people's health.

"This is not to say that people need to be afraid of taking vitamins and minerals," Byers explained. "If taken at the correct dosage, multivitamins can be good for you. But there is no substitute for good, nutritional food."

It is advised not to take vitamin supplements as tablets or syrups but intake through natural vegetables is good for health.

By Lizitha