About 1 in 3 adults in the U.S. reported using dietary supplements and prescription medications concomitantly, say researchers from the Military Nutrition Division in Natick, Massachusetts, who analyzed data from the 2005-2008 National Health and Nutrition Examination Survey.
Prevalence of concomitant use was highest among people with osteoporosis, followed by thyroid, cancer, kidney, arthritis, diabetes, heart/vascular, respiratory, and liver conditions.
Supplement-and-medicine use was significantly more common among people with a doctor-informed medical condition (DIMC) (1 in 2 adults) vs those without (1 in 6 adults). Among people with a DIMC, cardiovascular agents were the most common drugs used with supplements. Among people without DIMC, hormones were the most common.
The number of people using both supplements and medicines has risen in recent years. More than 10 years ago, 16% to 18% of prescription medication users also took supplements, the researchers note. A study published in 2008 found the prevalence (at least among adults aged 57-85 years) was up to 52%. In the current study, 69.3% of prescription medication users aged ≥ 57 years were using supplements concomitantly.
Concomitant use was widespread across all medical conditions. Thus, the researchers say, it may not be feasible to identify individuals with a specific condition who merit increased attention relative to others. Rather, they say, a broad spectrum of patients may benefit from education and guidance on the risks of interactions, particularly the potential of supplements to interfere with the metabolism and potency of prescription medications.
Multivitamins containing “other” or botanical ingredients were more commonly consumed than were standard multivitamins. The increasingly complex combinations of ingredients contained in supplements may require closer evaluation by health care and dietetics practitioners. As important as it is to ask patients about their supplement use, it may be even more important to ask them about the ingredients on the labels.
Source
Farina EK, Austin KG, Lieberman HR. J Acad Nutr Diet. [Accepted online ahead of print January 23, 2014.]
doi: 10.1016/j.jand.2014.01.016.