Children's Hospital Colorado

Are Supplements Safe?

Sports dietitians frequently get asked by patients and parents about the safety and efficacy of sports nutrition products. Sports supplements are a $40 billion industry, and people are looking for that “magic” pill or powder to maximize their performance.

Athletes often wonder: Are any of the supplements on the market unsafe? Do I need to take a daily multi-vitamin? Which products will make me stronger, faster, leaner?

The reality is that there isn’t a definitive answer. The need for a supplement is individualized based on the athlete and choosing a “good” supplement is much more complex than just picking one off the shelf.

We spoke with sports dietitian Amanda McCarthy, an expert in our Sports Medicine Center, to learn more about dietary supplements – and whether they’re safe for your athlete.

Q: Are any of the supplements on the market unsafe?

A: “Yes. The question is… which ones? In 2009, Sports Illustrated published a fascinating article on the safety of sports supplements, ‘What you don’t know might kill you,’ highlighting the fact that the supplement industry is highly unregulated without standards for safety or efficacy, in other words, effectiveness.

The Dietary Supplement Health and Education Act of 1994 (DSHEA) allows supplement manufacturers to make health claims regarding the effect of products on body structure or function, although they cannot make restorative claims to ‘’diagnose, mitigate, treat, cure, or prevent’’ a precise disease or medical condition.

And in 2003, the Food and Drug Administration Task Force on Consumer Health and Information on Better Nutrition established the requirement that industry manufacturers must investigate the identity, strength and purity of their supplement products but once again does not require them to prove efficacy or safety.

More recently, a 2023 study on botanical ingredients in 57 supplements found that 89% of the supplements tested did not accurately declare ingredients in their product. Of those, 40% did not contain any detectable amount of the ingredient listed on the label, and only 6% contained the ingredient within 10% of the label’s stated amount.

So, what does this mean for consumers? Frankly, you don’t know if the product you are buying is safe, contains contaminants that are dangerous or illegal, has unknown side effects, et cetera. For elite and competitive athletes, contamination with illegal or banned substances may mean disqualification from competition or from their league.  

Q: Should I take a daily multi-vitamin?

A: “Most of us get the appropriate levels of vitamins and minerals from the typical daily diet. As long as you are eating a varied diet with a rainbow of colors, you are likely getting all you need. However, there are a few exceptions.

Competitive athletes who train at a higher level and have increased energy expenditure may benefit from the added calcium, iron, zinc and vitamins. Likewise, people who are at risk of a nutrient deficiency, such as vegetarians and vegans, people with food allergies or other dietary restrictions, may also benefit from multi-vitamins.  

In all supplements, it’s best to look for third-party certification as an added safeguard to ensure that what is on the product label is actually what is in the product. There are lots of certifications you may see on supplement labels, and the ones you see below are the ones that verify accuracy, or absorption and safety of the product. Even if you’re diligently choosing a vitamin, it’s important to know that errors and contamination have still been found in products, even with third party certification.”

Certifications include USPNSF, Informed Sport and BSCG.

Q: Which products will make me stronger, faster, leaner?

A: “While we know certain products may change the appearance of your body or improve your athletic performance, the reality is that most are unsafe, illegal or banned by major sports governing agencies. This would include anabolic steroids, pro-hormones (androstenedione, DHEA) and ephedrine.

While caffeine is legal and has been shown to have beneficial effects as a stimulant on aerobic activity and decreased perception of effort, it is restricted by the NCAA and International Olympic Committee above certain levels. The American Academy of Pediatrics (AAP) does not recommend any caffeine consumption in youth less than 12 years old. For athletes between 12 and 18 years old, the AAP recommends limiting caffeine to less than100 milligrams daily, or two 12 ounce cans of soda, one shot of espresso in a coffee drink or 6 ounces of coffee.

Protein supplements can be convenient but are typically not necessary as most athletes can easily meet their protein needs for growth, strength and speed through the foods they eat. Creatine, if pure in form, is the only legal product proven to increase muscle mass and increase exercise performance in short repetitive bouts of high intensity exercise, in other words, sprinting or weightlifting -- but not distance running. Creatine is found in the animal products we consume and produced by the liver as well.”  

However, this once again takes us back to the question of supplement safety.

“Even these presumably harmless over-the-counter products such as protein powders and creatine supplements have been shown to contain unsafe contaminants. Do you really want to ingest these products for the remote possibility it will improve your performance at the risk of also ingesting mercury, lead, pro-hormones or anabolic steroids?  In my opinion, the risk outweighs the benefit. If you want to improve all areas of your sports performance, I recommend eating a varied diet with a healthy mix of protein, carbohydrates, fats and colors. Appropriate training without over- or under-training, regular meals and snacks and rest are also key ingredients to get the most out of your athletic ability.”

Have you already started taking supplements? Check out the Operation Supplement Safety Scorecard as a first step to determine the level of risk you are taking with each supplement. If you have more questions or want individual guidance on supplementation, schedule with a pediatric sports dietitian.

Learn more about sports nutrition.