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Vitamins and Supplements: Do They Really Work?

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Vitamins and Supplements: Do They Really Work?

Apr 11, 2024

Many advertisements and online sources claim a certain vitamin or supplement is safe and will improve your life. The reality of these products is much more complicated than the marketing would have you believe. Nutritionist Thunder Jalili, PhD, shares his rules for assessing which supplements are actually effective and which are a waste of money—and how to make sure the supplement you're taking is actually safe for consumption.

    This content was originally produced for audio. Certain elements such as tone, sound effects, and music, may not fully capture the intended experience in textual representation. Therefore, the following transcription has been modified for clarity. We recognize not everyone can access the audio podcast. However, for those who can, we encourage subscribing and listening to the original content for a more engaging and immersive experience.

    All thoughts and opinions expressed by hosts and guests are their own and do not necessarily reflect the views held by the institutions with which they are affiliated.


    Interviewer: It seems like there is no shortage of supplements that promise to make you healthier, prevent illness, improve your performance, whatever. So how can a person determine if a supplement is legit or not?

    Thunder Jalili is a professor in the Department of Nutrition and Integrative Physiology at the University of Utah.

    Thunder, let's start the conversation. What is a supplement? What are we talking about here?

    What Are Vitamins and Supplements?

    Thunder: So technically, there's a law that was passed years ago that basically exempts nutrition supplements from any kind of research. So the research that's done to support their use is voluntary. Now, some supplement companies do it, and some don't, but basically, this law says nutritional supplements still count as food. So because they are basically in the food umbrella, they don't need to have research done on them.

    Interviewer: All right. A lot of medicines will have research done to make sure that they work and make sure they're safe and those types of things, but supplements don't.

    Quality Control: Purity and Integrity

    Thunder: Because of that classification, supplements don't have the same requirement to do all the health, safety, toxicity, and efficacy, and all that type of research that goes into a pharmaceutical.

    So to define supplements is tough because even though the law says they're not medicine, they kind of fall in the food realm. In reality, it's not really the food realm because it's not like they grow on trees. They're processed in some way. Either they're pure compounds made in the lab, or they're botanical extracts, or they're a botanical that was extracted and purified into one compound, or different things like that.

    Interviewer: And from a medical standpoint, nutritional supplements, those kinds of imply, "I'm not getting enough of something, so I need to take this thing to get more of that thing." Is that another way to look at it?

    Thunder: Yeah, exactly. And that is the whole impetus behind supplements. Now, the thing is you may think and you may have good reason to believe that you need a supplement because you do not have a certain nutrient or a certain botanical, or somebody may convince you that you need to have this nutrient or botanical in order to be healthy.

    So it kind of comes in both directions. And I think the way that society is now, it's very much the latter. There are so many products out there, and we have people who are trying to convince you that you need to take this or you need to take that to avoid cardiovascular disease or to enhance your exercise performance, etc.

    Interviewer: Yeah. And I think maybe another way to look at it, too, is it's not just a lack of something. It's this idea that if you get more of a thing, it's going to do the things you just mentioned, enhance performance, or make you healthier, or something of that nature.

    Thunder: Yeah, exactly. Maybe supplements long ago started off life as a way to keep people from becoming nutritionally deficient in various vitamins and minerals, but it's definitely grown quite a bit in the last 100 years. And a lot of it now is just having extra of something in order to have some beneficial effect.

    Interviewer: Yeah. A lot of supplements come with a promise, it seems like, right?

    Thunder: They do. And oftentimes, that's all it is, is a promise. You don't really know as a consumer. You're kind of rolling the dice a little bit unless you land on something that has research behind it where you can be a little bit more confident that you're going to see an effect.

    Guidelines for Taking Vitamins and Supplements

    Interviewer: Okay. And what are your general rules that all of us should keep in mind before we start thinking about adding a different supplement?

    I take a few supplements, and I was thinking about how I ended up taking these particular supplements. And part of it is maybe a friend recommends it. Maybe I'm taking one because a doctor thought it would be a good idea. Maybe I'm taking another one, like a multivitamin, because I think, "Well, better be safe than sorry," and just go ahead and take that multivitamin.

    Do you have any general rules when it comes to you considering maybe adding something?

    Multivitamins May Not Be for Everyone

    Thunder: Yeah. Since you mentioned multivitamins, I will say I don't think everyone should take a multivitamin. That's very much an individual thing, because there's enough research out there that shows sometimes taking a multivitamin or vitamin supplements can actually increase the risk of certain cancers or . . .

    Interviewer: Oh.

    Thunder: Yeah, which is kind of scary, or heart disease.

    Ingredient Awareness: Know What You're Taking

    But yeah, just a couple of basic important general rules. Number one, most importantly, know what it is you're taking. And that may sound really stupid, but it's amazing that a lot of people will take a supplement that they're recommended to take and have no idea what's in it. I think that's a very basic thing. Know what's in the supplement you're taking, and know what it's supposed to affect, what it's supposed to do.

    Interviewer: It's kind of funny how somebody might take a supplement without knowing what's in it or what it does when we would never see a bottle of something lying on the sidewalk, open it up, and just consume it if it said, "Hey, get stronger. Drink me." Nobody would do that.

    Thunder: Exactly. Or if somebody gave you some really crazy-looking food and said, "Just stick it in your mouth," you would say, "Well, what is this? What's in it?" Yeah, but for some reason, we do that with supplements.

    And there's a lot available online that . . . Companies make claims, people buy it, people take it, and they really don't know what's in that.

    Interviewer: And I think another quick rule for that, knowing what's in it and what it does, is you've got to be careful at the website you're looking at, right? I did a Google search before we had this conversation, and two of the websites I found said, "These are the supplements you should take." Upon closer examination, one was an affiliate link page, which means they're making money when you click on the Buy This Supplement, and the other one was just straight on a company that was selling supplements, right? So I don't know that I necessarily trust them 100%.

    Thunder: No, you're exactly right. The supplement industry is big business. It's not well regulated, and most people get into the supplement industry to try to make money. So it's different than the pharmaceutical industry, because the pharmaceutical industry, yes, people want to make money, that's part of it, but they have to show efficacy and they have to show safety. And so you have kind of a dual mandate there, and supplements, you don't always have the second part, that it's useful.

    Interviewer: All right. So your first rule: know what you're taking, what's in it, and what it's supposed to do. What's your next rule?

    Research Efficacy: Separating Promise from Reality

    Thunder: Yeah, my next rule is to do the best you can to find out if there's actually research that supports the efficacy of the supplement. So in other words, if somebody gives you that packet of mystery stuff and says, "Oh, you should take this. It's going to increase your energy levels," do a little homework. Find out the ingredients.

    I mean, it'd be best to talk to a nutritionist or a dietitian, but Google it at least and see if there's any data that shows those ingredients are effective for what it's supposed to do.

    There are enough resources out there, like WebMD and other places, where you can get information on supplements. So that's my second rule. Know what you're taking, and then see if there's actual research and evidence that it does what it's supposed to do.

    Interviewer: And be sure that when you are looking up that research, that it is coming from a legitimate trusted source, and somebody doesn't have ulterior motives for telling you that information. And if they talk about the research, make sure that they're actually linking to those research studies . . .

    Thunder: Yes.

    Interviewer: I think that is what I would recommend and what I found when I was doing some research.

    Thunder: Yeah, exactly. And that's why I mentioned WebMD just as an example, because that's a fairly good website. And if you really want to be savvy about it, the websites that do talk about supplements or provide evidence of supplements, oftentimes will have a reference list, like where they got their information, and you can look at those, too.

    And one thing I'll say, if the list supporting the supplement is mostly cell culture studies, no animal studies, no human studies, I would be skeptical because the reality is that almost any botanical phytochemical vitamin, or whatever you find, can do something in cells. But 99.9% of them fail by the time they get to humans. So be skeptical of research that only involves cells. At least we want to see animal studies, and preferably, we'd want to see some human studies.

    Assessing Risks and Side Effects of Vitamins and Supplements

    Interviewer: All right, Thunder. So we talked about you really should know if a supplement . . . the efficacy of it, meaning does it work, does it do the things that it's saying it does. You should do your due diligence, and look for some research. But what about that safety aspect? I think a lot of people can think, "It's a supplement. It's natural. There aren't really any safety considerations." But that's not true.

    Thunder: Yeah, absolutely. Our idea is that if something is natural it has to be safe, that's totally wrong. Think about this. Radiation is natural, right? But we generally accept radiation is not safe.

    Interviewer: Especially in large amounts like you're dealing with, with supplements. Sometimes you're taking large amounts that you could never consume in food.

    Thunder: Yeah, exactly. So just get rid of that notion that just because it's natural, it's safe.

    Having said that, there are some general considerations for supplements. So most of the vitamins and minerals that we have out there, they've been studied quite a bit for a long time. There are upper tolerable level intakes that have been set for these.

    So what I would recommend if anybody is going to take an individual vitamin or mineral supplement, they can go and just double-check that their dosage is underneath that UL, that upper tolerable limit. In general, if you're hovering right around the RDA, you have nothing to worry about.

    There are a few that may be a little more risky, like if people are taking vitamin A supplements, for example. It's actually a pretty low dose that can still provide toxicity, so you want to be careful about that. Most people don't take high amounts of vitamin A orally, but they may be prescribed vitamin A cream, like Retin-A, or Accutane, which is a pill, or something like that.

    And then there's a website that the Office of Dietary Supplements runs. This is an office through the National Institutes of Health, and it really has fantastic information about all vitamins and minerals, and even a good amount of herbal supplements. So I think would be a go-to resource for anyone who wants to know more information.

    And then the last part of that general story with supplements is we do have a lot of herbals out there now. And when I say herbals, I'll include things like grape seed extract that everyone is familiar with, or green tea extract, but also even individual compounds that can be isolated from herbs, things like resveratrol, or quercetin, or things like that.

    Some of these herbal compounds may have potentially higher risk than others, and the risk is not necessarily maybe from a toxicity standpoint, but from the standpoint that they could have drug interactions. One reason why you may see that is because some of these herbal compounds may depend on the same mechanisms as a drug you may be taking for either absorption or distribution throughout the body, or maybe even detoxification and excretion.

    And so when you're assigned a drug, you're given a dosage that takes all that stuff into consideration to still have enough drug left over after your body degrades it to do its job. But if you take an herbal supplement that could also be using those same pathways, that could impact how that drug actually works.

    So the short of it is it's very important to tell your doctor what supplements you may be taking, especially what herbal supplements you may be taking, so they're aware of that and they can look it up and make sure they can make adjustments if they have to.

    Interviewer: What about the safety of the actual ingredients in the supplement? Since it is not regulated to the extent that regular medications would be regulated, you don't always necessarily know what's in there.

    Thunder: Yeah, exactly. So the concern that I have in general is maybe a little less about safety. I mean, there are always some safety issues. Red yeast rice, I'll just pick on that one because it's at the top of my mind right now. People take this red yeast rice extract to lower cholesterol, and it kind of works, but there may also be other compounds in that red yeast rice that potentially could cause kidney problems or liver problems, right?

    It depends quite a bit on what batch it is, and who the manufacturer is. The levels vary across the board. There's no regulation like you have with a drug where every dose has to be exactly the same no matter who makes it.

    And the other thing, kind of beyond the safety thing, but just the efficacy and does it work, is a lot of times you may have varying levels of the effective ingredient. Or maybe they're not even present at all. They're totally not there.

    And, again, to pick on red yeast rice extract, this has been found in the past where one brand will have X amount of the active ingredient and another brand will have absolutely nothing. So that's kind of a tricky bit.

    So if you're taking a supplement to treat a medical condition, I would be careful about that. You may actually be better off with the actual pharmaceutical instead.

    Interviewer: Got it. And then what about compounds in there that you don't know about? Does that happen often? Isn't there, for supplements, some sort of a certification that some supplements can voluntarily do that shows that it's pure or it doesn't have other additives or something like that?

    Thunder: Yeah. The key point you just hit on, Scot, is voluntary. Some supplement companies are very good in that they hold themselves to a high standard. They test their products. They make sure they use purified ingredients. They're very public about this because they're trying to get their market advantage as being a good player in the field and giving you a pure honest product. But there are other companies that don't do this.

    So I would definitely gravitate towards the more well-known brands that actually have some sort of research they do on their product, or some sort of data behind them showing that the ingredient is in there, and it's shown to do this and that.

    And you have to look for that. As a consumer, we have to dig for it because it's not required. The FDA doesn't require this stuff because they're supplements, and they're classified technically as food. It's not a drug, so it's on us to do our homework.

    Interviewer: So maybe finding the cheapest stuff or ordering some stuff online might not be the best idea when it comes to supplements because you're rolling the dice.

    Thunder: You're rolling . . .

    Interviewer: I think you were about to say you're rolling the dice.

    Thunder: Exactly. I was going to say that. You are rolling the dice, and sometimes you get what you pay for.

    I remember when I was a little kid, there was an advertisement for helmets, for motorcycle helmets. I used to ride motorcycles. And Bell, this company that makes helmets, used to advertise, "If you have a $10 head, get a $10 helmet." It reminds me of that. So, yeah, the cheapest is not always the best.

    Especially with herbals, I like to gravitate towards something that has a data stream behind it. For example, grape seed extract is a popular one to take to lower blood pressure. There are lots of different brands out there, but there have been a couple of brands that have actually been studied in clinical studies, and clinical trials. I would buy those brands personally.

    Same thing with turmeric, and curcumin, another really popular supplement. There are certain brands that have been studied, and that have been analyzed for pharmacokinetics. I would get those brands. They're not the cheapest ones. I'll tell you that right now. They'll probably cost 5 or 10 times as much as the cheap stuff you get, but I know there's a data stream behind it that shows it has some effectiveness.

    Balancing Effectiveness and Placebo Effects

    Interviewer: There are instances where somebody has already taken a supplement. For whatever reason, it's been recommended, whatever, and they really think it works for them, and there's no research to support that. I found myself in that situation. Is there any harm in just taking that because it's working for me?

    Thunder: So I'm fairly open-minded about that part of it. In anything we take, the placebo effect can be pretty powerful. It's been said the placebo effect can give 30% or 40% of the overall effect.

    So my position is if it's a supplement that is safe, has safe ingredients, the levels of the ingredients are not too high, it's not something that has a toxicity risk, you feel it has a benefit, and you can afford to pay for it, then go for it. So I'm okay with that.

    There are a lot of people who do kind of swear by supplements, and it makes them feel better that they're taking what they're taking. And again, as long as there's not a risk for harm from that, I think that's okay.

    Seeking Professional Health Guidance

    Interviewer: Probably a good idea to talk to your doctor about it as well since they would also be . . . or a nutritionist. They would be educated on those aspects that you just brought up.

    Thunder: Yeah. And I think, honestly, a dietitian or a nutritionist would be a better source.

    Interviewer: Oh, okay.

    Thunder: When it comes to supplements, doctors have no training in nutrition or in supplements, per se. And so you get a mixed bag. You get some physicians who are really savvy because they're interested in nutrition, they're interested in supplements, and they've taken their own time to educate themselves and are coming from a position of expertise in medicine and physiology. So they're good, right?

    But then there are other doctors that just . . . they're busy and they don't care that much about it, so they don't really know anything about nutrition or supplements. So it's hit-and-miss getting information from a doctor.

    I would say if your doctor falls into that former category where you've talked nutrition, and you know they're into it, and you know they've educated themselves, they can be a good source. But otherwise, your more reliable source would be a dietitian or a nutritionist.


    updated: April 11, 2024
    originally published: August 26, 2022