Are you considering taking dietary supplements on your health quest? If you’re vigorously nodding, you ain’t alone! But are supplements safe and effective?


Dietary supplements include vitamins, minerals, probiotics, herbs, and amino acids. They come in many forms — like pills, powders, liquids, and bars — that you can eat or drink.

Many people take dietary supplements to fill in the nutritional gaps in their diet. Others supplement in hopes of preventing disease or achieving specific wellness goals.

The evidence on whether dietary supplements are effective is mixed.


Supplementing may help you by:

  • providing nutrients you can’t get from your diet
  • increasing your levels of nutrients if you have deficiencies
  • supporting overall and specific wellness goals
  • complementing mainstream medical treatment plans
  • offering alternative therapeutic options


On the other hand, dietary supplements may:

  • interact with medications
  • worsen existing health conditions
  • cause side effects or allergic reactions
  • complicate surgery
  • lead to new — potentially serious — health issues

More than half of all American adults use supplements on the regular (and the percentage soars as we age). Given that dietary supplements might be part of your self-care strategy, ya might wanna know if they’ll help you reach your desired outcomes, such as boosting overall well-being or warding off illness.

Or will they just make your pee rainbow-colored and expensive? Worse, could dietary supplements be harmful to you? We popped the capsule of truth to let you know what’s what.

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Let’s take a look at what dietary supplements may do for you — and whether they live up to that potential.

Dietary supplement benefits

There’s a huge variety of dietary supplements on the market — from vitamin A to zinc and everything in between — that aim to address a spectrum of health conditions.

We’re going to lump them into three categories:

  • Providing general wellness support. This is your litany of multimineral + multivitamin formulas, probiotics, etc. Maybe you’d take these daily to cover for a less-than-stellar diet/sleep regimen/fitness plan. These don’t target particular health issues, instead aiming to boost day-to-day physical and mental well-being.
  • Addressing specific health issues. You might take a supplement regimen with a specific health objective. For example, maybe you down some calcium + vitamin D to improve bone health. Or, to get real specific, folks with age-related macular degeneration might take a combination of vitamins C and E, zinc, copper, lutein, and zeaxanthin (aka AREDS) to slow down vision loss.
  • Preventing illness or injury. Instead of using supplements to help with an existing issue, you may consider them a preventive measure. This, too, might mean taking a certain supplement for a specific reason. For instance, pregnant people often take folate or folic acid supplements to lower the risk of certain fetal development issues.

In a nutshell, there are countless dietary supplements that may yield benefits for an equally countless number of physical and mental health concerns. Buuuuuuut…

Efficacy of dietary supplements

Oh, wow, now this is a doozy of a topic. To put it mildly, effectiveness of dietary supplements is… inconclusive.

Observational studies vs. controlled trials

The number and quality of studies on dietary supplements is pretty uneven.

Many existing studies are observational, meaning that the researchers didn’t use any control groups. This could render the findings a bit skewed. Controlled randomized studies often generate results that are totally different from those of observational studies.

Certain celebrity supplements — like magnesium and potassium — have enjoyed being the subject of much research, so there’s a lot more hard data available to analyze on those.

Other supplements (the up-and-comers) don’t necessarily have loads of studies backing them, so there are still pretty big question marks about their effectiveness.

Clearly, we could all benefit from continued investigation of the effects of supplements.

When can’t you get nutrients from your diet?

Getting your nutrients from a healthful, well-balanced diet can be way more effective than getting them from supplements. (Plus, it could be cheaper and tastier!)

But certain groups of people can’t get the nutrients they need through diet alone for a variety of reasons, so supplements may be essential.

Dietary restrictions may lead to nutrient deficiency in some people (vegans, for example). An inability to fully absorb B12 from food as we age (which might be due to low stomach acid levels) or increased nutrient needs seen in hypermetabolic states like cancer might also be responsible.

Whatever the cause, supplements can plug these gaps in nutritional intake.

Supplements can also be really helpful for correcting a vitamin D deficiency. This type of deficiency is super common, and vitamin D doesn’t pop up in many foods. Vitamin D deficiency is much more common in people with obesity and people with certain health conditions.

So, unless you’re getting ample sunshine and are in perfect health, you have a pretty good chance of developing low vitamin D levels or a full-on deficiency.

Common meds — including certain types of birth control, metformin, and statins — can also deplete nutrients in your body. This can make it hard to get optimal amounts through your diet alone.

Chew on that for a bit…

Dietary supplements could be really useful if you can’t get all the nutrients you need from food sources. This may be due to:

  • Dietary habits. Following a restrictive diet like a keto or vegan diet increases your chances of nutrient deficiencies.
  • Lifestyle factors. You may travel a lot, work long hours, or live somewhere without access to a wide variety of nutritious foods.
  • Physical considerations. You may not be able to eat or digest certain foods and may need another method of getting nutrients. Folks who are pregnant or breastfeeding often need supplements. Certain medical conditions also increase the chances of developing nutrient deficiencies. For example, people with type 2 diabetes are more likely to be deficient in nutrients like B12 and magnesium.
  • Personal health history. Maybe you have a mineral deficiency or your doc thinks amping up your levels of a few key minerals will address a particular health challenge.

As with any substance you’re putting in or on your body, supplements come with a chance of an unintended negative response — like an allergic reaction, side effects, or interactions with medications you’re taking.

The FDA doesn’t regulate dietary supplements in the same way as drugs — instead, it regulates them in a similar way to food. This means it doesn’t have the authority to weigh in on the safety or effectiveness of a supplement. That responsibility is left to the supplement maker.

Manufacturers are supposed to ensure that supplements are safe before bringing them to the marketplace. Another buuuuuuuut…

Dietary supplement side effects and adverse reactions

The marquee nutrient in many supplements — the ginger or curcumin or echinacea, for example — is usually considered safe for most people when taken properly. The government deems these substances “generally recognized as safe” (GRAS).

But probs can come up. In fact, on average, there are about 23,000 ER visits per year for adverse events related to dietary supplements.

So, what are the biggest issues? Well…

  • Side effects. Common side effects include upset stomach, diarrhea, headaches, and nausea — the usual grab bag of feeling icky. But side effects can also be serious (like liver damage or fetal development issues) or even life threatening.
  • Allergic reaction. As with foods, you can have an intolerance or hypersensitivity to a supplement. Allergies can manifest as itching, swelling, rashes, and even anaphylaxis.
  • Overdosing. If a little is good, a lot must be super, right? WRONG! Exceeding the max recommended amounts of some supplements can lead to serious long-term or irreversible effects. Unless your doctor advises something different, read and follow package guidelines for dosing and usage.
  • Complications with existing medical conditions. Some supplements don’t mix well with certain medical conditions. Taking a supplement that doesn’t jibe with an existing health issue can cause serious problems.
  • Interactions with drugs or other supplements. Yup, sometimes combining supplements with prescribed meds, over-the-counter meds, or other supplements isn’t meant to be. (More on this in a sec.)

There’s a lot you can do to make supplementation a safer experience. Isn’t it great to have personal agency?

Ask your doc

Confirm that the supplements you’re considering are a good idea for you, specifically. Before starting a new supplement routine, it’s a good idea to touch base with a healthcare professional. After all, you want to make sure you’re tending to your unique needs in the safest and most effective way possible.

If you have a go-to doctor or other healthcare pro, they know your individual medical profile. They’ll be able to advise you on how a certain supplement might interfere with other meds you’re taking or impact any health conditions you may have.

Some supplements can block the absorption or alter the effects of medications. For example, your body may not absorb the full amount of your prescribed drugs.

Here are some common supplements that don’t mingle so nicely with certain prescription medications:

Also note that:

  • Most research on the safety of supplements doesn’t include pregnant or nursing women or children.
  • Supplements and surgery can be a poor pairing. If you’re going under the knife, you may need to stop taking dietary supplements well in advance of your operation.

Be a savvy consumer

If you want quality products, you’re gonna have to do some due diligence. That means using common sense plus doing solid research on the supplement and manufacturer. You can better evaluate the potential safety and effectiveness of a supplement once you’re armed with information.

Here are some tips to get you started:

  • Look to noncommercial sources — like government or academic websites — for info. It’s probably legit to assume that supplement sellers are going to have a bias — they want you to buy their pills and potions! Sellers might not be trying to do harm, but it’s not unthinkable that they’d put a positive spin on every aspect of their products.
  • Disregard inflated claims. If it sounds too good to be true, it probably is. Run from items that boast about curing health conditions, burning fat, or other questionable claims.
  • Keep in mind that “natural,” “organic,” and “herbal” are not synonymous with “safe.” Just because a supplement is derived from the bosom of Mother Earth doesn’t mean it’s 100 percent A-OK 100 percent of the time for 100 percent of users. Plus, there are so many other factors at play, like normal variations in the crops your supplement was made from, the production processes of the manufacturer, and YOU.
  • Read the package label. Beware of weird added ingredients or snuck-in contaminants.
  • Buy supplements only from reputable companies. You want to ensure that the folks making your supplements follow the FDA’s current Good Manufacturing Practice (cGMP) guidelines and labeling regulations. You can also check to make sure there are no FDA warning letters issued to the product maker.
  • If you take a supplement and happen to experience a problem with it — report the issue to the FDA. In this context, snitches avoid stitches.
  • Forms matter. Some supplements contain forms of nutrients that aren’t as easy for your body to absorb as others. If you have questions about which form of a specific nutrient you should be taking, consult a healthcare pro such as a registered dietitian.

Dietary supplements are vitamins, minerals, and other substances designed to enhance your nutrition. Supplements come in many oral forms, like pills, powders, liquids, bars, and gummies.

People take supplements with hopes of maintaining or improving overall wellness, addressing specific health conditions, or preventing illness or injury. Each supplement offers unique potential benefits.

Supplementation does come with some risks. You might experience adverse effects or allergic reactions. Talk with a healthcare pro before starting any supplements, especially if you have existing medical concerns.

More and better research is needed to determine the safety and effectiveness of most supplements.

As always, your diet should be your primary source of nutrients. This is why it’s important to eat a nutrient-dense, varied diet. However, some people may need to take one or more dietary supplements for a number of reasons.

It’s best to work with your healthcare team when considering dietary supplements. They can help you decide whether supplements are necessary for your specific needs and, if they are, which ones are most effective and safe.