taking too many vitamin pills can increase cancer risk

published by : The Telegraph
21 Apr 2015

Taking too many vitamin tablets can increase your heart disease and cancer risk, new research has warned.

Over the counter supplements are promoted for their health benefits but exceeding the recommended daily amount may have a counter effect.

Dr Tim Byers of the University of Colorado Cancer Centre 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."

Two decades ago research found those who ate more fruits and vegetables tended to have less cancer so Dr Bryers began to investigate if taking extra vitamins and minerals would reduce cancer risk even further.

But the associate director for cancer prevention and control added: "When we first tested dietary supplements in animal models we found that the results were promising.

"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.

"We found that the supplements were actually not beneficial for their health. In fact, some people actually got more cancer while on the vitamins."

Too many vitamin tablets could be bad for your health

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 per cent.

Folic acid, which was thought to help reduce the number of polyps in a colon, actually increased the number in another trial.

Dr Bryers said: "This is not to say that people need to be afraid of taking vitamins and minerals.

"If taken at the correct dosage, multivitamins can be good for you. But there is no substitute for good, nutritional food."

He added most people get the daily recommended doses of vitamins and minerals in their diets by eating healthy meal and warned: "At the end of the day we have discovered that taking extra vitamins and minerals do more harm than good."

The findings were presented at the American Association for Cancer Research Annual Meeting 2015.


Recommended Readings

1. Vitamin health warning: Too many supplements can 'boost' risk of cancer and heart disease, The Express UK

2. Vitamins & Minerals, Cancer.Net

3. Vitamin supplements and cancer, Cancer Council NSW

4. Multivitamins Linked to Breast Cancer Risk, WebMD