What Is a Dietary Supplement? Definition & What to Know

According to Dr. Cara Welch from the FDA, 75% of Americans take dietary supplements.⁽¹⁾

Dietary supplements have become a part of our daily life, filling in the gaps in our daily nutrition that our normal diet may lack. They’ve become a staple of the American kitchen counter. Grand View Research reports that the global dietary supplements market is projected to reach $414.52billion by 2033.⁽²⁾But what is a supplement?

A dietary supplement is a product that includes such ingredients as vitamins, minerals, herbs, amino acids, and enzymes. They come in forms such as tablets, capsules, soft gels, gelcaps, powders, and liquids.⁽³⁾

Supplements are not meant to replace nutritious meals. As their name suggests, supplements are meant to “supplement” a healthy diet. They provide nutrients and other ingredients extracted from food sources or synthetically made.

What Are Dietary Supplements?

So, what is a dietary supplement? The dietary supplement definition encompasses a broad category of products designed to support your daily nutritional intake. Supplements are concentrated sources of nutrients that provide nutritional or physiological benefits.⁽³⁾

These products bridge the gap between what your body needs and what your regular meals provide. Unlike medications, dietary supplements don't require FDA approval before hitting store shelves, though manufacturers must ensure their products are safe and properly labeled.

While prescription drugs treat specific medical conditions, dietary supplements support general health and wellness. They work alongside your regular diet to help maintain optimal nutrition levels and support various bodily functions.

What Are the Benefits of Dietary Supplements?

The right supplements can offer several advantages when used appropriately as part of a healthy lifestyle. Understanding these benefits helps explain why millions of Americans incorporate them into their daily routines.⁽⁴⁾

• Addressing deficiencies: Many people struggle to get adequate amounts of certain nutrients from food alone. Supplements help your body receive the essential nutrients it needs to function.

• Convenience in meeting daily needs: Modern life doesn't always allow for perfectly balanced meals every day. A high-quality multivitamin or targeted supplement can provide peace of mind that you're covering your nutritional bases, even on hectic days.

• Supporting health during different life stages: Nutritional needs change throughout different life stages. Pregnant women may benefit from folic acid, older adults may need more vitamin D, active individuals might require additional protein support, and those with a sedentary lifestyle might benefit from supplements that support cellular energy. Supplements can address these evolving needs.

• Potential long-term health benefits when used appropriately: When taken properly, certain supplements may support cellular health, immune health, and healthy aging. While not magic bullets, they can be valuable tools in a comprehensive wellness approach.

What Forms Do Dietary Supplements Come In?

Supplements come in different forms, so you can pick what works best for you. They can impact absorption, convenience, and certain types might be easier on your stomach.

• Tablets: These compressed forms are stable, cost-effective, and offer precise dosing. 

• Capsules: Whether hard or soft gel, capsules can provide better bioavailability than tablets for certain nutrients. They're perfect for oils, powdered herbs, or nutrients that are easier to take in capsule form, like Tru Niagen's NAD+ precursor.

• Powders: Mixing powders into drinks or food allows for flexible dosing and may support faster absorption. They're popular for protein supplements and specialized compounds like NAD+ supplements, which are available in convenient stick pack options.

• Liquids: Liquid supplements can be more convenient  than solid forms and work well for people who have trouble swallowing pills. They're common for children's vitamins and certain herbal extracts.

• Gummies: These chewable options make supplementation more enjoyable, especially for those who dislike traditional pills. However, they often contain added sugars and may have lower nutrient concentrations.

What Are the Different Types of Dietary Supplements?

Dietary supplements consist of numerous categories, each serving different health goals and nutritional needs. Understanding these types helps you make better decisions about what might benefit your specific situation. Let's take a look at the different types of dietary supplements available:

Vitamins

What are vitamins? Vitamins are organic compounds your body needs in small quantities.⁽⁵⁾

Vitamins are essential because the human body cannot produce an adequate amount needed for sustainable function. Certain vitamins are not produced by the body at all and are solely dependent on the intake of your diet.⁽⁵⁾

For example, while your body is able to create the active form of vitamin D through exposure to sunlight, it is unable to create vitamin C and relies solely on your food intake.

However, the deficiencies of either vitamin can lead to serious ailments like loss of bone density or scurvy, respectively.

There are currently 13 recognized vitamins, and they are classified as either fat-soluble or water-soluble.

• Fat-soluble vitamins, like vitamins A, D, E, and K, are easily stored in the body because of their ability to be stored in the fatty tissues of the body. Your body can hold these vitamin reserves for days or weeks at a time, making good use of your food when ingested.

• Water-soluble vitamins, like vitamin C and all the B vitamins, require constant intake due to their inability to be stored in the body for long periods of time. Your body quite inefficiently excretes these vitamins in urine if not readily used. Therefore, the maintenance of these vitamins in the body requires a little more attention when considering your food choices.

For example, the vitamin B3 family, niacin, nicotinamide, and nicotinamide riboside, are all water-soluble, meaning they need daily consistent replenishment to meet your body’s required vitamin B3 intake.

Minerals

Minerals are inorganic substances that your body requires for daily function. Minerals in your diet are essential to the body for things like bone health, muscle contraction, nerve function, and controlling body fluids.⁽⁶⁾

Unlike some vitamins, minerals cannot be created in the body at all. Minerals rely solely on your diet to obtain adequate amounts. The five major minerals your body requires for good health are calcium, phosphorus, potassium, sodium, and magnesium.⁽⁶⁾

All other minerals are considered “trace minerals”, meaning that your body only requires a small amount of them. “Trace minerals” include iron, manganese, copper, iodine, zinc, cobalt, fluoride, and selenium.⁽⁷⁾

Herbs

Herbs, also known as botanicals, have a long history of medicinal use in ancient civilizations as far back as 5000 BCE. Traditional Chinese medicine still uses herbs as part of its practice today.

In the Western market, herbs fall within the dietary supplement category instead of standard medicine.

As with any other supplement, herbal dietary supplements cannot claim to be a treatment for a disease or illness under the eyes of the FDA.

By definition, the term herb refers to a herbaceous plant, characterized by the lack of a woody stem and often grown low to the ground. However, there have been several exceptions to this categorization when it comes to the extensive use of herbal supplements.⁽⁸⁾

Some examples of how herbal dietary supplements are used:

• Ginseng to help manage stress, support the immune system, and reduce fatigue.

• Chamomile to help improve sleep quality and support relaxation.

• Cinnamon to help with appetite and blood sugar maintenance.

• Ginkgo Biloba to help support blood circulation.

Amino Acids

Amino acids are organic compounds that are vital building blocks of proteins. Your body needs 20 different kinds of amino acids for proper functioning.

Nine of these 20 are essential amino acids because they cannot be made in the body and can only be obtained through diet. These nine essential amino acids are as follows: histidine, isoleucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine.⁽⁹⁾

The best sources of essential amino acids come from complete proteins like meat, dairy products, soy, and other plant-based sources, such as quinoa, buckwheat, beans, and nuts.

Amino acids are largely recognized for their role in muscle development and repair, but they have several other important functions, such as building antibodies, hormones, and enzymes.

Enzymes

Enzymes are proteins that function as biological catalysts, meaning that they are responsible for chemically mobilizing or accelerating chemical reactions in the body.⁽¹⁰⁾

Supplemental enzymes largely fall into one of two categories: digestive or systemic.

Most people are familiar with digestive enzyme supplements that help with food digestion, like lactase (used to break down milk sugar), often found in Lactaid® products.⁽¹¹⁾

Systemic enzymes work in the body to help support the immune system and inflammatory processes. One of the functions of systemic enzymes is breaking down excess fibrin, a protein involved in the clotting of blood.⁽¹²⁾

Supplement Categorizations are Not a Perfect System

There are plenty of dietary supplement products available that don’t fit neatly into these categories, namely fatty acids or probiotics.

Some products lie within a subset that overlaps these categories, like metabolites. Metabolites are usually used to describe small molecules that lie within the intermediate or end products of cellular metabolism. They function as fuel, structure, signaling, or stimulatory and inhibitory effects on enzymes.⁽¹³⁾

Nicotinamide riboside is an example of a metabolite that supports NAD+ production in cells. As we age, enzymes like CD38 can deplete NAD+ levels, making supplementation with NAD+ precursors like NR increasingly important for maintaining cellular function. 

Are Dietary Supplements Safe?

As per FDA guidelines, supplements are not permitted to be marketed for the purpose of treating, diagnosing, preventing, or curing diseases. On the other hand, drugs are permitted for these uses if reviewed appropriately and approved by the FDA.

Ensuring the safety and efficacy of a supplement product is left to the discretion of the manufacturer. Companies like Niagen Bioscience hold quality to high standards, ensuring their facilities meet cGMP (Current Good Manufacturing Practice) regulations.

Although the FDA does not approve dietary supplement products, any supplement that contains a new dietary ingredient (an active ingredient introduced to the market after October, 1994) must be notified to the FDA prior to market launch.⁽¹⁴⁾

At any time, the FDA has the power to remove a product from the market if the product is found to be unsafe.

Keep in mind that this doesn’t mean that all dietary supplements you can buy online are safe. In fact, a recent report revealed significant quality concerns, with 76% of NAD supplements failing to meet label claims. 

Supplements Range in Quality and Proof

The wide range of dietary supplements on the market is overwhelming, but it’s important to stay vigilant of ingredient claims, safety, and efficacy.

Some ingredients, like vitamin C, have decades of scientific research to bolster their claims. However, the mass number of supplements also creates a muddled climate of varying degrees of quality and claim strength.

Before taking in everything you read as absolute truth, it’s important to exercise an extra level of scrutiny to check for irregularities behind a supplement and the company behind it. A good place to start is reviewing the merit behind a supplement’s clinical trials.

What Are the Potential Risks and Considerations of Dietary Supplements?

While supplements offer many benefits, they're not without potential drawbacks. Being aware of these risks helps you make safer, more informed choices about which products to include in your routine.

• Possible side effects and interactions with medications: Even natural ingredients can cause adverse reactions or interact with prescription drugs.⁽¹⁵⁾
  
  
• Over-supplementation: More isn't always better when it comes to nutrients. Fat-soluble vitamins like A, D, E, and K can accumulate in your body, potentially reaching toxic levels.⁽¹⁶⁾Following recommended dosages is crucial for safety, as well as consulting with your healthcare provider to ensure proper intake.
  
  
• Quality differences among brands: The supplement industry varies widely in manufacturing standards and quality control. Some products may contain contaminants, incorrect dosages, or ingredients not listed on labels. This inconsistency makes choosing reputable brands with third-party testing essential.
  
  
• The "natural" label misconception: "Natural" doesn't automatically mean safe or effective. Many natural compounds can be potent and potentially harmful in large doses or when combined with other substances. Marketing terms like "natural" or "organic" don't guarantee quality or safety.
  
  
• Not a substitute for a balanced diet: Dietary supplements can't replicate the complex nutritional benefits of whole foods. They lack the synergistic effects of nutrients working together as they naturally occur in foods. Eating plenty of fruits, vegetables, and lean proteins, as seen in the Blue Zone diet, provides nutritional benefits that no supplement is intended to replace.

How to Choose Supplements Wisely

Making smart supplement choices requires research, attention to detail, and a focus on quality over marketing claims. The right approach can help you find products that truly benefit your health while minimizing risks.

• Check for third-party testing and certifications: Look for seals from organizations like NSF International, USP, or ConsumerLab. These certifications indicate independent verification of ingredients, potency, and purity. Third-party testing gives you an extra layer of quality assurance beyond manufacturer claims.

• Read and understand the supplement facts label: Pay attention to serving sizes, active ingredients, and daily value percentages. Check for unnecessary fillers, artificial colors, or allergens. Understanding labels helps you compare products and avoid ingredients that might cause reactions.

• Look for transparency in ingredient sourcing and dosage: Trustworthy brands are transparent about ingredient sources and clearly list the exact amounts of active compounds in their products. Stay away from proprietary blends that use unclear language to mask ingredient quantities.

• Research the brand's reputation: Investigate the company's history, manufacturing practices, and any FDA warnings or recalls. Look for brands that invest in clinical research and have transparent business practices. Companies with good reputations typically provide detailed product information and responsive customer service.

• Tailor choices to individual needs, not trends: Your supplement needs are unique to your diet, lifestyle, health status, and goals. What works for others may not be appropriate for you. Consider factors like age, gender, activity level, and any health conditions when making choices rather than following popular trends.

Wrapping Up: What to Know About Dietary Supplements

Understanding what dietary supplements are and how they work empowers you to make informed decisions about your health. These products can be helpful for addressing nutritional gaps, supporting specific health goals, and maintaining wellness throughout different life stages. 

As the science of nutrition and aging continues to evolve, compounds like NAD+ precursors are exciting developments in how we support cellular health and the aging process. Tru Niagen's NAD+ supplements are backed by extensive clinical research and manufactured to pharmaceutical-grade standards, making them a trusted choice for those looking to support their cellular health. When choosing any supplement, prioritize those with solid research behind them, high manufacturing standards, and remember that supplements work best when they complement healthy lifestyle choices.