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Do You Know How to Choose and Recommend a Safe and Quality Supplement?

By Jorie Janzen | October 3, 2017

As a sports dietitian, athletes continuously ask me about supplements. Which ones are safe? What brands are best? What will keep me healthy? What will allow me to excel? Years ago I would have said, “Just choose a well-known brand”, or “Just buy what is on sale”, or “All supplements are pretty much the same”! And, of course, I have even suggested that, “If you eat a balanced diet, you won’t need supplements”
And, I think if it were not for the fact that I work with athletes, I might just be saying the same thing today!  However, I came to realize that when an athlete’s medal, sport’s career and life long reputation could be taken away in an instant, I started my journey on how to be better equipped to ensure the safety of my clients.
To make a recommendation for or against a supplement should be an evidenced based decision, which may be difficult for athletes or the general consumer. I hope that dietitians can be a go-to source for this information by understanding the safety, efficacy and appropriateness of supplementation. 

Five key questions to expand your competency on supplementation
  1. Is the product safe? To assess the safety of a supplement, learn about Good Manufacturing Practices (GMPs), pharmaceutical grades, purity and interactions with other supplements or medications. Purity, for instance, refers to the levels of lead, pesticides, mercury, insecticides and other harmful substances. Contact the manufacturer to request a “certificate of authenticity” and to find out what GMPs have been practiced.  This certificate ensures that rigorous protocols have taken place. 

  2. Is it legal?  A significant number of supplements continue to test positive for banned substances – unintentional or not. When it comes to making sure the supplement is safe and legal, use the World Anti-doping Agency resources for ingredient checks.  (Keep in mind, this simply means that you are basing safety on what’s on the label, not necessarily what’s truly in the supplement).

    You could also check for banned substances through quality assurance programs such as Informed-Sport or Informed-Choice. These programs provide proof that the batch tested came out clean.  The best option however, is to have the sport certified product third party tested for safety – but this takes money. 

  3. Do you know what to look for on the label? Look for indication that the product has gone through a quality assurance program, where the product has been tested in the lab and also randomly at the retail level.  Two recognized certification programs are LGC or NSF.  

  4. Do you know how and when to recommend a supplement or a combination of supplements? This is probably the most important and one where most practitioners are least confident! We need to look at the evidence emerging and learn about effective doses and duration. Learn about side effects.  Which sports, health conditions, training situations require supplementation?  For athletes, some considerations are weight loss, body composition, nutrient intake – and even travel as they may be going to a competition in a location where food safety is questionable. 

  5. 5. Is there evidence it will work?  The evidence is extremely important.  We also need to look at supplements used in studies as well as outliers.  Outliers are ignored too often.  What if you were the outlier?  Would you not want to know why supplementation did or did not work for you?  Great resources are PEN and DC networks. I also like to look at and The NutriSearch Comparative Guide to Nutrition Supplements.
Other considerations to discuss with clients:
  • Side effects.  High doses can be harmful, as can interactions with other supplements and medications.
  • Affordability.  More expensive may mean a higher quality product.  However, not everyone can afford these supplements.  Be ready to provide clients with supplements options in different price ranges.
  • Form of supplement.  Some forms are more bioavailable than others.


Jorie Janzen is the director of sport dietetics for the Canadian Sport Centre Manitoba and holds a private practice working with corporate health and wellness, and athletes with disordered eating. She received her undergrad degree at the University of Manitoba and furthered her education with the IOC Diploma in Sport Nutrition, and is a Certified Life Coach. Some of her experiences have come from working with various national and international networks, provincial, national and Olympic/Paralympic level athletes, the NHL, Royal Winnipeg Ballet, RCMP, and Sport Medicine Fellowships. With each opportunity, Jorie coaches clients to thrive in an environment that expects high performance on demand. Connect with Jorie at

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