November 2014

Concomitant Dietary Supplement and Prescription Medication Use Is Prevalent among US Adults with Doctor-Informed Medical Conditions

With studies suggesting that the number of US adults taking dietary supplements has increased to 50% in recent years, it is becoming increasingly important that dietitians gain a more thorough understanding of supplements and their effects on overall health. One danger when taking a dietary supplement is the potential for an interaction with prescription medications. The authors of this study recognized that there is currently a lack of research that could help dietitians identify those who might be at risk for dietary supplement-prescription medication interactions, hence the reason for this study.

The authors pulled their subjects from NHANES, and used a final sample size of 5106 men and 4934 women, aged 20 and older. It is important to note that antacids, calcium/magnesium tablets, multivitamins, and minerals are all categorized as dietary supplements in this study. A key finding is that those with doctor-informed medical conditions were far more likely to use prescription medications or dietary supplements than those without a doctor-diagnosed condition. The group with the highest prevalence of dietary supplement use was persons diagnosed with osteoporosis. Those with kidney conditions were the largest group of prescription medication users. This study’s findings suggest that as many as one third of US adults are taking a dietary supplement and a prescription medication concomitantly. Even more striking, this study finds that 70% of adults 57 and older are taking a dietary supplement and prescription medication concomitantly.

Multivitamins, antacids, single vitamins, and fish oils are the most prevalent among supplements taken by US adults. Cardiovascular agents were the most prevalent prescription medications being taken among adults with a doctor-informed medical condition. Hormones were the most prevalent prescription medication among adults without a doctor-informed medical condition.

The researchers conclude that more education and guidance on supplement usage is warranted, especially within the context of being taken concurrently with prescription medication. Furthermore, the researchers note that multivitamins with botanicals were the third most prevalent supplement being used with a medication, and, given this fact, dietitians may need to familiarize themselves with the growing ingredient lists on multivitamins.

Farina, E. K. Austin, K. G., Harris, R. (2014). Concomitant Dietary Supplement and Prescription Medication Use Is Prevalent among US Adults with Doctor-Informed Medical Conditions. Journal of the Academy of Nutrition and Dietetics, 114(11): 1784-1790. doi: 10.1016/j.jand.2014.01.016

Link: http://www.andjrnl.org/article/S2212-2672(14)00106-3/abstract

Supplemental Article:

Sood A, Sood R, Brinker FJ, Mann R, Loehrer LL, Wahner-Roedler DL. (2008). Potential for interactions between dietary supplements and pre- scription medications. American Journal of Medicine, 121(3): 207-211. Retrieved from: http://dx.doi.org/10.1016/j.amjmed.2007.11.014

Link: http://www.amjmed.com/article/S0002-9343(07)01187-4/abstract