You’ve probably heard of and/or seen someone take some sort of vitamin or health supplement at least once in your life before. With the global dietary supplements market projected to be worth $230 billion dollars by the year 2027, you’re bound to see a lot more of them in the near future.
But what exactly are they? What kind of benefits do they provide, if any at all?
Ahead, we cover what they are, why and who may take them, blends, ingredients, and more!
Dietary Supplement Products & Ingredients
In the United States, dietary supplements, products, and ingredients are regulated by a federal organization called the Food & Drug Administration, commonly referred to as the FDA, for short.
The FDA released the Federal Food, Drug, and Cosmetic Act in 1938, which “defines a dietary ingredient as a vitamin; mineral; herb or other botanical; amino acid; dietary substance for use by man to supplement the diet by increasing the total dietary intake; or a concentrate, metabolite, constituent, extract, or combination of the preceding substances.”.
Dietary supplements always come in an oral form, or in other words, taken by mouth. Despite only one mode of administration, they can still appear in a variety of forms, such as tablets, capsules, powders, liquids, tinctures, and even gummies, surprisingly enough!
An important thing to note about dietary supplements is that they are not allowed to make exorbitant or exaggerated claims; particularly ones that drugs and pharmaceuticals are allowed to make. These include phrases such as “treats depression” or “cures cancer.” Notice those definitive words “treat” and “cure’. This is why you’ll always come across the same disclaimer (or some similar variation) on every dietary supplement marketed in the United States, which is:
“This product is not intended to treat, diagnose, prevent, or cure any disease.”
And if you don’t see one of these disclaimers on a bottle or packaging, you should be wary of the said product.
Why Take Dietary Supplements?
There are a wide variety of reasons people use to justify taking particular dietary supplements. While everyone’s reasoning may be slightly different from the next person, most of them revolve around one core problem (or at least the person’s belief that a problem is present and needs to be addressed); that being the problem of deficiency.
A nutrient deficiency is a lack of any particular nutrient. These can be a wide variety of things; vitamins, minerals, and amino acids, just to name a few. Before we continue, it’s important to know what these nutrients are and what their purpose(s) are.
These are micronutrients that your body needs in order to grow and develop, as well as to maintain normal bodily functioning. Overall, there are 13 vitamins that your body requires in sufficient amounts in order to attain this normal functioning:
- Vitamin A
- Vitamin B
- Thiamine (B1)
- Riboflavin (B2)
- Niacin (B3)
- Pantothenic acid (B5)
- Pyridoxine (B6)
- Biotin (B7)
- Folate (B9)
- Cobalamin (B12)
- Vitamin C
- Vitamin D
- Vitamin E
- Vitamin K
Vitamins can be split up into two subcategories, known as water-soluble and fat-soluble
- Water-soluble: These are the B and C vitamins, and as the name implies, they dissolve in water.
- Fat-soluble: These are the A, D, E, & K vitamins. These dissolve in fat, which is sometimes also referred to as lipids.
While it’s possible for most people to obtain these vitamins naturally through their diets, there are some exceptions to the rule where a person should supplement their current intake of a particular vitamin. A common example of this are those considered to be vegetarians, as they commonly are deficient in Vitamin B12 .
Minerals have a wide variety of functions. They are responsible for manufacturing particular enzymes and hormones, as well as keeping your major organ systems working properly, such as your bones, heart, brain, and muscles. Like vitamins, minerals have two subcategories of their own; macrominerals and trace minerals.
- Macrominerals: the prefix “macro-” implies that your body needs a larger amount of these relative to trace minerals. Some of the most common macrominerals you’ll come across on food labels and dietary supplements are:
- Trace minerals are a subtype of mineral that you only need a small amount of. These include:
An amino acid can be thought of as a constituent, or broken down component, of protein. There are 21 common amino acids that help to maintain and optimize bodily functioning, but 9 of the 21 amino acids are considered to be essential. This means that your body cannot produce these 9 particular amino acids on its own. Your body requires you to obtain this either via diet or dietary supplementation. These 9 amino acids are:
Again, just like with vitamins, most individuals are able to obtain these essential amino acids through just their diet alone. However, those that classify as vegetarians or vegans, for example, may need to supplement with one or more of these amino acids in order to address particular deficiencies.
Something important to note here is that you might hear the term conditionally essential thrown around in the world of amino acids. These are particular amino acids, in addition to the 9 essential ones above, that are usually not essential to the human body but happen to be in specific circumstances. The conditionally essential amino acids include:
These are helpful during times of illness or of high stress (e.g. strenuous exercise), where the body cannot produce these particular amino acids fast enough relative to the increased demand for them.
Who Should Be Taking Dietary Supplements?
This is highly dependent on the context of the person’s characteristics and particular situation. As previously mentioned, a significant majority of people don’t need dietary supplements in order to reach a level of intake that is considered to be adequate according to a measure known as the Recommended Dietary Allowance, or RDA for short.
Recommended Dietary Allowance: This is the daily dietary intake of any particular nutrient considered to be sufficient by the U.S Institute of Medicine and FDA to meet the requirements of 97.5% of healthy individuals .
However, there are specific populations that may have trouble reaching the RDA for particular nutrients. These include, but are not limited to:
- Pregnant women
- Conditions that cause nutrient malabsorption
- (e.g. celiac disease, Crohn’s disease, lactose intolerance)
- Malnourished individuals
There are also some deficiencies that are more common in the general population, such as vitamin D and magnesium [4,5]. If you’re concerned that you may not be getting enough of a particular dietary ingredient, talk with your physician about what course of action would be best for you.
Something that should be considered is if a manufacturer uses any sort of proprietary blends in their products. This means that the company has provided a special blend of ingredients for a specific purpose. The drawback here is that although the ingredients themselves are listed, the dosages of them included in the product are not disclosed.
Supplement manufacturers often use proprietary blends as a way to keep the specific formulations they use a secret from prying eyes, in this case that would be other dietary supplement manufacturers. Which is understandable. Unfortunately, this also keeps the consumer in the dark as well. Though usually not a deal-breaker, it is typically best for the average person to avoid products with proprietary blends; so that you know how much of each specific ingredient that you are consuming on a regular basis.
Proprietary blends are commonly used in pre-workout sports supplements, but also throughout practically all supplement categories. For example, you might see a pre-workout supplement with a particular blend of amino acids labeled “Essential Amino Acid Complex”. This is then followed by an amount in grams (7g for example), followed by all the essential amino acids that the product contains down below.
Keep in mind, the 7 grams refers to the amount of total essential amino acids in the product, not the amount of each amino acid. So in this case, the consumer does not know how much of each amino acid is included in the product.
Food Ingredients vs. Supplement Ingredients
A common concern that is brought up by those interested in taking dietary supplements is whether or not the ingredients found in supplements are as effective as the ones found in whole foods. And the unfortunate answer to this concern is that we don’t quite know how they compare exactly in terms of bioavailability, or the amount that is consumed versus the amount that is actually able to be absorbed and utilized by the body .
But what we do know is that supplements are inferior to whole foods based on the fact that whole foods contain a myriad of additional health-promoting ingredients (e.g. phytochemicals, antioxidants), whereas dietary supplements only contain a select amount of nutrients, depending on the supplement that you purchase and often the quality.
Add to this the fact that dietary supplements aren’t as heavily regulated as food and drug products in the United States. In fact, per the FDA’s Dietary Supplement Health and Education Act of 1994 (DSHEA), supplements are essentially treated under the guise of “innocent until proven guilty”. In other words, an adverse event, adulterated, or mislabeled product has to be reported to the FDA in order to bring up a case against the product and its manufacturer, and this is after it has already been released to the public market .
This isn’t to say that dietary supplements are inherently unsafe. They generally are, it’s just that you may not always be getting the amount of nutrients you think you might be getting as you would from a whole food source of that same ingredient.
The best way to ensure that you’re getting a product that’s safe and effective is by purchasing from a manufacturer that participates in third-party testing. Third-party testing is not required by law, but rather it is a voluntary step in the manufacturing process so that manufacturers can prove to you that they produce high-quality products that are worth your investment. A certificate of analysis (COA) is awarded by independent third-party companies such as ConsumerLab and NSF to companies whose products pass certain tests in order to ensure:
- Supplement label accuracy
- No banned substances are included in the product
- That the product is free from any sort of contaminants
- That the same amount of each ingredient is consistent throughout multiple batches of the same product
NSF, in particular, is very helpful for athletes, as an “NSF Certified for Sport” certification states that the product is free from any banned substances as deemed by the World Anti-Doping Agency (WADA) 
We should all remember that dietary supplements are just that; a supplement. A supplement is defined by Merriam-Webster as something that completes or makes an addition . That explains the original purpose of dietary supplements, which is to serve as an addition to your current diet, which should be diverse and well-rounded by itself.
The supplement can then be added to “complete the diet” in a sense and fill in any gaps that you may have. These products aren’t meant to be used instead of a good diet. That’s just not how it works. In fact, research suggests that some individuals taking multivitamin/multimineral supplements use them as justification for a poorer diet .
Potential Interactions & Contraindications
It’s always important to ask your healthcare professional before beginning a supplement regimen, particularly if you are taking any medications. For example, it’s common for people to take milk thistle for its proposed liver health benefits. However, what many don’t know is that milk thistle decreases the concentrations of any medications that are metabolized by the enzyme CYP2C9, such as the blood thinner Warfarin or the benzodiazepine Valium .
Remember earlier when we were talking about the RDA created by the Institute of Medicine? Well, that’s part of a broader scale of dietary recommendations called the Dietary Reference Intake. The Dietary Reference Intake also contains a measure called the Tolerable Upper Intake Level (UL), which refers to the highest amount of a nutrient that can be consumed safely and is unlikely to cause negative side effects in the general population .
Taking too much of any one particular ingredient can cause harmful and/or dangerous side effects. This is much more common in fat-soluble vitamins in comparison to water-soluble vitamins. In fact, it’s quite rare for water-soluble vitamins (Vitamins B & C) to cause toxicity from an overdose. However, this doesn’t mean that you should have a free-for-all with your water-soluble vitamins, as you can still suffer from things like digestive upset and diarrhea if you take an absurd amount in one sitting .
However, the story is quite different for fat-soluble vitamins (Vitamins A, D, E, & K). For example, too much vitamin A can cause nausea and blurred vision . Excess vitamin D may lead to bone loss, as megadoses of this vitamin can potentially lead to low levels of vitamin K2, which is essential for bone health .
Remember, it’s important to make sure our diets are in check before adding a dietary supplement into the mix. Make sure that you speak with your healthcare provider before taking any supplement in order to ensure that it won’t interact with any potential medications that you’re currently taking. Look for manufacturers that use third-party testing practices so that you know you’re paying for an effective product. As long as you keep these things in mind, you’ll be sure to find the dietary supplements that are right for you and your goals!
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- Pawlak, R., Lester, S. & Babatunde, T. The prevalence of cobalamin deficiency among vegetarians assessed by serum vitamin B12: a review of literature. Eur J Clin Nutr 68, 541–548 (2014). https://doi.org/10.1038/ejcn.2014.46
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