Why a Registered Dietitian Is Skeptical of the Supplement Industry
Walk into any pharmacy, health food store, or scroll through social media for more than five minutes, and you'll be confronted with an overwhelming wall of supplements promising everything from boundless energy to flawless skin and a sharper mind. The global supplement industry is booming, and it shows no signs of slowing down. But according to registered dietitian Josie Porter, most of what's lining those shelves isn't worth your money — and some of it may not even be what it claims to be.
Porter, who spent a decade working in clinical nutrition settings and is the author of How Not To Take Supplements, has had a front-row seat to one of the most significant shifts in health culture of recent decades. She has watched supplements evolve from targeted treatments for medically diagnosed deficiencies into everyday wellness products marketed to people who simply want to optimize their health, performance, or appearance.
"I've seen the stacks of supplements getting longer over time," Porter told Business Insider. "So I can definitely see how the supplement industry is becoming more and more profitable, and more and more popular."
That popularity, however, doesn't necessarily translate to effectiveness. And for Porter, the first problem starts long before a capsule even reaches your mouth.
The Regulation Problem: You May Not Be Getting What You Paid For
One of the most important — and least discussed — facts about dietary supplements in the United States is that they are not regulated by the Food and Drug Administration (FDA) in the same way that pharmaceutical drugs are. This means that supplement manufacturers are largely responsible for ensuring the safety and accuracy of their own products before they hit the market.
In practice, this creates a significant problem for consumers. Without mandatory third-party testing, there is no reliable guarantee that a supplement contains the exact ingredients listed on the label — or in the amounts specified. A product could contain more of a nutrient than stated, less, or in some cases, none at all. In other instances, supplements have been found to contain undisclosed substances, some of which can be harmful.
Porter emphasizes that this regulatory gap makes it critically important for consumers to look for products that have been independently verified by third-party organizations. Certifications from bodies such as NSF International, USP (United States Pharmacopeia), or Informed Sport provide a meaningful layer of assurance that what's on the label is actually in the bottle.
Beyond the question of quality control, Porter also points to the issue of misleading health claims. Supplement advertising can be persuasive and emotionally compelling, but the scientific evidence backing many of those claims is often thin, cherry-picked, or based on studies that don't reflect real-world use. As a dietitian trained to evaluate nutritional research critically, she approaches supplement marketing with a healthy dose of skepticism.
Food First: The Foundational Philosophy
Before getting into which supplements Porter does take, it's worth understanding her foundational philosophy: a food-first approach. This means prioritizing whole, nutrient-dense foods as the primary source of vitamins, minerals, and other essential compounds — and only turning to supplements when diet alone genuinely cannot meet a specific need.
This isn't just a personal preference. It's grounded in decades of nutritional science showing that nutrients absorbed through food come packaged alongside fiber, antioxidants, phytonutrients, and other compounds that work synergistically in ways that isolated supplements simply cannot replicate. Eating a handful of almonds, for example, delivers vitamin E alongside healthy fats, magnesium, and fiber — a combination that no capsule can fully reproduce.
That said, Porter is clear that there is a time and a place for supplements. Certain life stages, health conditions, dietary restrictions, and geographical factors can make it genuinely difficult or impossible to meet all nutritional needs through food alone. In those cases, targeted supplementation based on evidence — and ideally guided by a healthcare professional — can make a meaningful difference.
The 3 Supplements a Dietitian Actually Takes
Given her clinical background and critical eye for evidence, Porter's personal supplement routine is notably minimal. She takes just three supplements — each chosen because the science behind them is strong and because they address genuine nutritional gaps that are difficult to close through diet alone for many people.
1. Vitamin D
Vitamin D deficiency is one of the most common nutritional shortfalls in the modern world, particularly in regions with limited sunlight exposure during autumn and winter months. While the body can synthesize vitamin D through sun exposure, many people — especially those who work indoors, live in northern latitudes, or have darker skin tones — simply don't get enough. Few foods are naturally rich in vitamin D, making supplementation one of the most evidence-supported recommendations in mainstream nutrition. Vitamin D plays a critical role in bone health, immune function, and mood regulation, among other processes.
2. Omega-3 Fatty Acids
Omega-3s, particularly EPA and DHA found in oily fish, have an extensive body of research supporting their benefits for cardiovascular health, inflammation reduction, and brain function. For people who don't regularly eat fatty fish such as salmon, mackerel, or sardines — including vegetarians and vegans — an algae-based or fish oil omega-3 supplement is a well-supported option. Porter takes this supplement because the gap between recommended intake and actual consumption is significant for a large portion of the population.
3. A Targeted Supplement for an Individual Deficiency
The third supplement Porter takes is one tailored to her own specific nutritional needs — a reminder that supplementation is not one-size-fits-all. Rather than recommending a single third supplement universally, she underscores the importance of getting blood work done and working with a registered dietitian or doctor to identify any genuine deficiencies before adding anything to your routine.
What This Means for You
The takeaway from Porter's approach isn't that supplements are bad — it's that more is rarely better, and that marketing should never substitute for evidence. Before adding a new supplement to your routine, ask yourself whether your diet could address the gap first. If you do decide to supplement, look for third-party tested products, stick to evidence-backed nutrients, and consult a qualified healthcare professional to make sure it's actually appropriate for your individual needs.
In a market designed to make you feel like you're always one capsule away from optimal health, a little professional skepticism goes a long way.