Given the increased use of dietary supplements with little or no professional guidance, we identified a need to explore the prevalence and determinants of dietary supplement use in populations at risk including university students. In fact, there is evidence to support the harmful implications of contamination with prohibited substances, supplement-supplement interactions, supplement-drug interactions, allergic reactions, and incorrect product dosing when taking dietary supplements without or with little professional guidance. Irrespective of physical activity levels, we identified a prevalent use of supplements among Canadian athlete and non-athlete university students. Overall, 58.3% of varsity athlete and 43.4% of non-athlete students at the University of Guelph, Ontario, Canada, reported having used at least one type of dietary supplement in the past six months. Although most participants referred to healthcare professionals for information on dietary supplements, many continued to depend on unreliable sources including family, friends, peers, the internet and the media. Using the Theory of Planned Behavior model to explore the psychosocial determinants of supplement use, attitude, injunctive norm and perceived behavioral control were found to be significant predictors of the intention to use dietary supplements, and attitude, injunctive norm and intention were significant predictors of engaging in the supplementation behavior. These findings highlight the need for the development and dissemination of additional nutrition education programs and resources on dietary supplements, their benefits as well as their potential risks.
Dr. Dalia El Khoury received a BSc in Nutrition and Dietetics (2002) and an MSc in Nutrition (2005) at the American University of Beirut, Lebanon. Afterward, she completed her PhD in Physiology and Physiopathology at the University of Pierre et Marie Curie, France (2008). Dr. El Khoury then served as a lecturer at the American University of Beirut (2009-2010), and as a postdoctoral fellow and sessional lecturer at the University of Toronto, Canada (2010-2014). Later, she joined an international leading company in infant and child nutrition, Mead Johnson Nutrition, as senior scientist in Global Regulatory and Nutrition Science for approximately two years (2014-2016). Currently, Dr. El Khoury is an assistant professor in the department of Family Relations and Applied Nutrition at the University of Guelph, Canada. One of her lines of research aims at identifying novel biomarkers for the metabolic syndrome both in children and adults.