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Taking Supplements? Tell Your Doctor

Oct. 13, 2006 -- If you're taking prescription medicines, you may be overdue to tell your doctor about any dietary supplements you're taking.

Many people taking prescription drugs haven't told their doctors that they also use dietary supplements -- and that may be risky business, in some cases.

So say Paula Gardiner, MD, and colleagues in the Archives of Internal Medicine.

Gardiner works at Harvard Medical School's division for research and education in complementary and integrative medicineintegrative medicine.

The researchers encourage health care providers to "regularly ask their patients with chronic conditions and prescription medications about nonvitamin dietary supplement use."

But patients needn't wait for the doctors; they can broach the topic themselves.

The goal is to make sure your doctors know about all of the things you take -- including supplements -- so they can help you safeguard and enhance your health.

Supplement Study

Gardiner's team studied data from a 2002 national health survey of more than 31,000 U.S. adults.

The survey listed 35 nonvitamin dietary supplements including fish oil; St. John's wort; melatonin; ginseng; glucosamine and chondroitin; echinacea; and ginkgo biloba.

Participants were asked if they had used "natural herbs" for their own health or treatment in the past year.

They were also asked if they had told their doctor about any use of nonvitamin dietary supplements, and whether they had taken any prescription drugs in the past year.

About two-thirds had taken prescription drugs in the previous year.

Twenty-one percent of those participants had taken supplements at some point during the previous year, compared with 16% of people who hadn't taken prescription drugs in the past year.

Among prescription drug users, the most commonly used supplements included echinacea, ginseng, ginkgo, and garlic, the researchers note.

According to Gardiner's team, an estimated 135 million people in the U.S. used prescription medicines in the previous year.

Prescription Drugs, Supplement Use

Nearly 70% of participants who reported taking prescription drugs and supplements at some point in the past year said they hadn't told their doctors about their supplement use.

"In general, prescription medication users with chronic but not life-threatening conditions (menopausemenopause, chronic gastrointestinal conditions, headaches, and insomniainsomnia) tended to have high nonvitamin dietary supplement use," the researchers write.They add that "those with chronic and life-threatening conditions (cardiovascular disease, strokestroke, and diabetesdiabetes) had the lowest rates of nonvitamin dietary supplement use."

Women and people with higher education levels were among those who were more likely to have used prescription medicines and supplements at some point in the past year.

It's not clear whether participants had used supplements and prescription drugs at the same time.