Supplement Basics

A supplement can be a nutrient or product intended to benefit your health or athletic performance.

Supplements are not regulated, so choose supplements that have undergone third-party testing. A food-first approach is always recommended, and supplements may be necessary in addition to optimize health and performance. A sports dietitian can assess your dietary intake and help you determine if a supplement is needed for your goals.

What is a supplement?

A supplement is defined by the International Olympic Committee (IOC) as:

A food, food component, nutrient, or non-food compound that is purposefully ingested in addition to the habitually consumed diet with the aim of achieving a specific health and/or performance benefit¹.

Supplement Types

Supplements are often used to support health, address nutrient deficiencies, or improve athletic performance and recovery.

Supplements cannot replace proper fueling, hydration, and recovery, but they can further enhance your health and performance potential.

Are you considering starting a supplement? If so, it’s important to ask yourself the following questions:

Do I need a supplement?

For sports foods and medical supplements, it is important to assess your nutritional status to determine if you are already getting the nutrients you need through dietary intake. In many cases, an adequate, varied diet provides foundational nutrient needs while also giving the body other beneficial ingredients like fiber. Whole foods also have a lower risk of containing banned substances than supplements³. A sports dietitian can assess your dietary intake and help you determine if a supplement is needed.

A performance supplement can be used to meet the needs of nutrients that cannot be adequately met by food alone. When considering a performance supplement, consider your goals to determine which supplement might be most appropriate.

There are many situations in which a supplement can be helpful:

• Convenient, portable fueling
• Nutrient deficiencies
• Food allergies
• Dietary limitations
• Digestive tolerance
• Increased nutrient demand
• Recovery support
• Performance enhancement

Is taking a supplement safe & legal?

Supplements are not regulated like over-the-counter drugs and medications. This means that their manufacturing is not checked for quality or safety, and there is a risk of contamination and mislabeling^4,5.

The lack of regulation also means that supplements could inadvertently contain substances that are banned, and can impact your ability to compete. A 2025 study looking at 200 commercial products found that 35% of them contained substances banned by the World Anti-Doping Agency (WADA)⁶. A review suggests that 10-30% of supplements contain prohibited substances⁷.

Athletes should be up to speed yearly on the WADA List, to understand what substances are banned. The list is reviewed annually and updated every January.

Look for supplements that have been tested for quality and purity by third-party verification.

Companies that provide third-party certification

NSF Certified for Sport

Informed Sport

Banned Substances Control Group (BSCG)

Cologne List

HASTA