Eyebrow raising number more that 15% of old Americans are living with risk of very harmful drug reaction, because of consumption of dietary supplements alongside prescription medications

Vitamins and amino acids Dietary supplements popularity is on the rise in U.S. in tag with prescription drugs. The percentage increased from 53.4% to 67.1% of old aged Americans between age of 62 to 85, taking 5 or more prescription pills or supplements.

New study found that mixing of these two substances can lead to side effects and some serious reactions. Example Warfarin used as blood thinner joined with popular supplement omega-3 fish oil, can increase dangerous risks of heart disease.

Researchers picked up the list of 20 most common prescription medicines and supplements to examine. Results were found risky with negative side effects, 16 combinations of prescription medications, over-the-counter drugs and supplements were predicted of risk. Bleeding was the most common side effect detected.

To lower risks, Doctors to be better informed about the cocktail of medications their patients are on, but more comprehensive information should also be provided about potential drug interactions, said Qato.

"The message for doctors is that we need to be more proactive about asking patients about things going on in their lives and the different therapies they're using," Dr. Michael Steinman, professor of medicine at the University of California-San Francisco, told CNN. "And there's really a lesson in there for patients, that it is really useful for doctors to know which therapies you're taking, even if they're things the doctor didn't prescribe."