Every 24 minutes, someone calls a poison control center in the U.S. regarding exposure to a dietary supplement, according to a new study from the Central Ohio Poison Center and the Center for Injury Research and Policy. Both institutions are at Nationwide Children's Hospital, one of the nation's largest pediatric hospitals and research institutes.

About 71 percent of adults in the United States take dietary supplements, according to the Council for Responsible Nutrition (CRN), and 84 percent of Americans express overall confidence in the quality, effectiveness and safety of these supplements.

While most dietary supplements are generally recognized as safe (GRAS), exposure to dietary supplements can cause adverse effects, particularly in children. The popular supplement yohimbe, for example, can cause arrhythmias, renal failure, seizures, heart attack and death. Energy products can also cause cardiovascular and respiratory problems, seizures and other clinical issues in children.

"Many consumers believe dietary supplements are held to the same safety and efficacy standards as over-the-counter medications," Gary Smith, M.D., DrPH, senior author of the study and director of the Center of Injury Research and Policy at Nationwide Children's, said in a press release.

"However, dietary supplements are not considered drugs, thus they are not required to undergo clinical trials or obtain approval from the FDA prior to sale, unless the product is labeled as intended for therapeutic use."

In the study, published online in the Journal of Medical Toxicology, researchers wanted to determine the incidence and distribution of dietary supplement exposures in the United States. To do this, they performed a retrospective analysis using information about the 274,998 dietary supplement out-of-hospital exposures reported to National Poison Data System from 2000 to 2012.

The researchers found that the yearly rate of dietary supplement exposures for every 100,000 people increased by more than 46 percent during 2000 to 2002, decreased nearly 9 percent during 2002 to 2005, and then increased again by nearly 50 percent from 2005 to 2012.

The researchers categorized the overall number of exposures according to type and found that miscellaneous dietary supplements were responsible for the majority of exposures, accounting for 43.9 percent of all exposure reports. Botanicals accounted for 31.9 percent of exposure reports, hormonal products accounted for 15.1 percent of exposures, and exposure to other supplements were name in 5.1 percent of reports. Categories associated with the greatest toxicity included huang products, yohimbe and energy products.

Most reports of dietary supplement exposure — 70 percent occurred among children under the age of 6. Of these pediatric exposures, 94 percent were acute and 82 percent were unintentional.

According to the study, there was an overall increase in the rate of dietary supplement exposures from the years 2000 through 2012. While most of these exposures did not require medical treatment or result in a serious medical problem, exposure to certain products were associated with substantial toxicity.

The researchers concluded their study by saying the results "demonstrate the success of the FDA ban on ma huang products and the need for FDA regulation of yohimbe and energy products in the USA."

"Lack of federal oversight has led to inconsistencies in the quality of dietary supplements, product mislabeling and contamination with other substances," said Henry Spiller, MS, D.ABAT, a co-author of the study and director of the Central Ohio Poison Center at Nationwide Children's.

"Although the majority of these exposure calls did not result in serious medical outcomes, exposures to yohimbe and energy products can be dangerous, suggesting the need for child-resistant packaging, caregiver education and FDA regulation of these substances."