Many people take a multivitamin daily, or specific vitamins for a particular reason, like Vitamin C to ward off a cold. But a growing body of research shows that, for many people, taking supplements may do nothing at all — and overdoing it by taking several times the recommended daily allowance can even be harmful. FDA oversight of vitamin supplements is limited, so it’s up to consumers to watch what they take. We explore the risks and benefits of taking your vitamins.


  • James Hamblin MD; Health Editor, the Atlantic
  • Tod Cooperman MD; President, Consumer Lab


  • 12:06:40

    MR. KOJO NNAMDIFrom WAMU 88.5 at American University in Washington, welcome to "The Kojo Nnamdi Show," connecting your neighborhood with the world. Later in the broadcast, in the wake of the Trayvon Martin verdict, the social science research behind unconscious bias and stereotypes. But first, many of us take a multivitamin daily, or perhaps we pop a vitamin C tablet to ward off a cold. Overall, Americans spend $11 billion a year on vitamin and mineral supplements.

  • 12:07:17

    MR. KOJO NNAMDIBut a growing body of research shows that, for many people, these supplements may do nothing at all, and overdoing it by taking supplements containing many times the recommended daily allowance can even be harmful. Making matters worse, the FDA's oversight of supplements is limited, so it's up to consumers to watch what they take. Joining us to discuss this is James Hamblin. He is health editor for The Atlantic magazine. He joins us in studio. James Hamblin, thank you for joining us.

  • 12:07:47

    MR. JAMES HAMBLINThank you very much for having me.

  • 12:07:49

    NNAMDIJoining us by phone from White Plains, N.Y., is Tod Cooperman. He's a medical doctor and president of Consumer Lab, an independent testing organization for health and nutritional products. Tod Cooperman, thank you for joining us.

  • 12:08:04

    MR. TOD COOPERMANThanks for having me on as well.

  • 12:08:05

    NNAMDIYou, too, can join the conversation. Call us at 800-433-8850. Do you take vitamin supplements? 800-433-8850. Tod, research has been coming out for years that taking too much of a particular vitamin supplement can actually be harmful. What are some of these findings?

  • 12:08:26

    COOPERMANWell, yeah. It's well established that you can get too much of a good thing with various vitamins and other supplements. For example, vitamin A, which you need, if you get too much of it, you can actually weaken your bones and cause other toxicities. Even vitamin D, which we now know is really helpful in many ways, even that at too high a level can be problematic. And the same goes with many, you know, other vitamins and other essential, you know, nutrients out there.

  • 12:09:04

    NNAMDIThe idea that the benefits of vitamins are oversold isn't really new, is it, Tod?

  • 12:09:11

    COOPERMANIt's been around, you know, forever. You know, people are always seeking a magic bullet. And, you know, supplements have their place. Certainly you don't want to be deficient in any nutrient, and there are other kinds of supplements out there -- you know, melatonin, et cetera -- which, used appropriately, can be helpful also. But there will always be people, you know, selling snake oil and lots of people wanting to believe, you know, that it will help them.

  • 12:09:40

    NNAMDIJames Hamblin, there's some psychology at work here, too, it would appear. As soon as people read about something having a health benefit, they tend to go out and stock up. What should people consider before they jump onto a vitamin trend?

  • 12:09:55

    HAMBLINWell, we're always looking for an easy answer, especially when it comes to anti-aging, preventing cancer. These sorts of buzzwords, they generate a lot of interest in news stories, and we see it dating back as far as the 1970s when Linus Pauling, who was very respected as a two-time Nobel laureate, championed this cause of vitamin C and, as a very respected scientist, said that it was going to add 25 years to our lives and prevent cancer. And it's -- we're still reeling and taking that down in terms of scientific studies that are saying, you know, it's not all that it seemed that it could be.

  • 12:10:32

    NNAMDI800-433-8850. Do you worry that taking a supplement could be dangerous? You can also send us a tweet, @kojoshow, email to Tod, we should make, I guess, some distinctions. There are multivitamins meant to be taken daily, but there are also what are known as megavitamins. What are those?

  • 12:10:52

    COOPERMANYou know, it's a loose definition, but it really means a vitamin that contains much more than the recommended daily intake of a nutrient. So, you know, when you -- when consumers look at the back of a supplement, they see that supplement facts panel. You know, often, you know, it's alluring to see, you know, 100 percent of this, 100 percent of that. And that's generally fine. But when you start seeing, you know, 1,000 percent, 20,000 percent, you know, these are the megadoses, which, unless you're deficient in something, you know, generally is not a good idea.

  • 12:11:26

    NNAMDIWhat are some of the potential issues? You say it's not a good idea. What are some of the potential issues with taking these megavitamins?

  • 12:11:34

    COOPERMANWell, you know, even with vitamin D, I think it's a great example because many people are truly deficient in vitamin D. You want to have a level, a blood level of about 25 to 35 nanograms per milliliter. Many people are even below 20, below 15. That's where you run into trouble.

  • 12:11:53

    COOPERMANBut a lot of people jumped on the kind of vitamin D bandwagon toward taking megadoses, pushing their levels up to, like, over 40, 50 nanograms per milliliter, where there's now evidence that it can actually decrease, you know -- basically negate some of the positive benefits of vitamin D in terms of your cardiovascular system, even your mortality. So you don't want to be getting too much, you know, of that or other vitamins.

  • 12:12:26

    COOPERMANAnd, you know, getting back to vitamin C, which James was talking about, you know, due to Linus Pauling promoting it, you know, in the past, you know, you take too much vitamin C, short term, you know, it's going to cause diarrhea. You know, it can upset your stomach. Long term, it may be actually having a negative effect 'cause you are -- you actually need -- you know, it's an antioxidant, but you actually need some oxidation activity in your body. And if you negate that with too much antioxidant, you know, there's now evidence that that can be bad for you as well.

  • 12:13:04

    NNAMDIIs there anything good, however, about vitamin C? We all generally take it because we think it helps to prevent us catching colds.

  • 12:13:11

    COOPERMANWell, absolutely. I mean, vitamin C is one of the earliest discovered vitamins. You know, you think back to the sailors who weren't getting enough and losing their teeth, getting scurvy. So absolutely you need vitamin C. But very few people, you know, in the United States have scurvy. So it's not doing really that much good if people are not deficient in it.

  • 12:13:31

    COOPERMANThe only evidence I've actually seen for taking vitamin D -- vitamin C when you're not deficient is in marathoners, kind of extreme athletes. It may help reduce the chance of getting a cold after a marathon. But in normal life, it has not been shown to have that benefit.

  • 12:13:49

    NNAMDIJames Hamblin, people also think that because they can buy these things in the local natural foods store, they're harmless. But is that necessarily the case?

  • 12:13:58

    HAMBLINNo. And part of our system of regulating medications creates this sort of health halo around the things that you can just go and buy in unlimited quantities, which falsely predisposes us to think that these are completely benign when, in fact, they're not.

  • 12:14:15

    NNAMDIEspecially if the food -- if the store says your natural food store, we tend to think that there's something fundamentally good about natural.

  • 12:14:22


  • 12:14:23

    NNAMDIIt's a good advertising technique. Tod, you won't necessarily find warning labels on vitamin supplements because they're not required, with one exception -- for iron supplements. What kind of oversight is there by the FDA of vitamin and mineral supplements?

  • 12:14:38

    COOPERMANI guess in terms of iron, you know, they're typically dangerous to kids, who can overdose. You know, in the past, before they had special lids on vitamins, you know, there was sort of a very serious negative reaction, I think even some death. So, you know, you don't want to overdose on iron. Most people will not, you know, taking a multivitamin. In terms of the regulation, the FDA does regulate the area, but the -- as you mentioned, the regulations are loose.

  • 12:15:09

    COOPERMANThey're not well enforced. Companies now are required to even -- to follow good manufacturing practices, which means they need to document how they're making their products, which they didn't have to do before. However, there's not a lot of teeth in these GMPs, good manufacturing practices. It doesn't specify, for example, how much lead contamination there can be in a supplement. That's left up to the manufacturer to decide.

  • 12:15:34

    COOPERMANWe at Consumer Lab, we're testing products, you know, and publishing that for consumers. You know, we're using very strict limits for these contaminants. We're making sure the ingredients are in there. So we're doing the things the FDA probably should be doing but has its hands tied, basically, and really doesn't even have the funding to do the things that it can do.

  • 12:15:58

    NNAMDIWe're talking with Tod Cooperman. He is an MD and president of Consumer Lab, an independent testing organization for health and nutritional products, and James Hamblin, health editor for The Atlantic magazine, about the benefits or lack thereof of vitamin supplements. We're taking your calls at 800-433-8850. Do you worry that taking a supplement could be dangerous?

  • 12:16:20

    NNAMDIDo you think there should be more regulation of vitamins and other supplements? 800-433-8850. James, last month, an op-ed in The New York Times by Dr. Paul Offit was the top story on the site for a while. You wrote a response to that, and Dr. Offit also published a follow-up. Tell us about the original article.

  • 12:16:40

    HAMBLINWell, it's originally based on a book that he's written, discussing the real benefits behind alternative medicine and supplements. And his op-ed was titled "Don't Take Your Vitamins," which can be a little bit reductive. There are certainly people -- and this is what I wrote in my response: There are certainly people who need them, people who have certain deficiencies, people who don't get enough sunlight, people with gastric bypass, children need certain vitamins and pregnant women. So to say that blanketly is difficult, to say we don't need vitamins, but it's a much more nuanced topic than that.

  • 12:17:22

    NNAMDIYeah, because as a health editor, you find that much of the wisdom in a piece like that gets lost.

  • 12:17:28

    HAMBLINYes. People tend to tweet that story or put it on their Facebook wall and read the headline or the first couple of paragraphs and then throw the vitamins out the window.

  • 12:17:39

    NNAMDIOn to the telephones. Here is Arianna in Winchester, Va. Arianna, you're on the air. Go ahead, please.

  • 12:17:46

    ARIANNAHey, guys. Thank you so much for taking my call. I've been taking melatonin as a supplement before I go to bed at night, and I've been slowly eking up the milligrams. And my husband is convinced that I'm going to become dependent on this. Is there any research on melatonin dependency?

  • 12:18:02

    NNAMDII'll ask both of our guests. First you, Tod Cooperman.

  • 12:18:05

    COOPERMANYes. Well, you know, melatonin is a hormone, so it's not something you want to really play around with too much. And you really shouldn't be taking it daily. It's not like a sleeping pill, you know, like an Ambien, which even has its own risks. But what it can do is it can help trigger sleep kind of set your clock to -- if you've been thrown off, you know, by travelling, et cetera, to help you fall asleep and if you take it about an hour or 45 minutes before you want to go to sleep. And you really don't need a lot.

  • 12:18:38

    COOPERMANYou know, many of the products out there have three to 10 milligrams. Frankly, you may get by with, you know, just one milligram of melatonin. I would not ramp up on melatonin 'cause, again, it is a hormone and it can affect other things hormonally within your body.

  • 12:18:55

    NNAMDIArianna, thank you very much for your call.

  • 12:18:57

    ARIANNAThank you so much.

  • 12:18:58

    NNAMDIAntioxidants were for a while considered something of a magic bullet, potentially warding off cancer and aging. But again, research shows that it's more complicated than that. What do we know about antioxidants, James?

  • 12:19:14

    HAMBLINWell, it's something that researchers are calling the antioxidant paradox where when your body -- when the mitochondria produce energy, they become these free radicals, which we know are involved in the cell aging process. And when you take in antioxidants, which are normally in fruits and vitamins or anti-oxidants, it can neutralize some of those free radicals and theoretically slow the aging process for those cells.

  • 12:19:39

    HAMBLINBut we've shown that in high-dose supplements, it actually has the reverse effect. So there is some balance where you need an amount of oxidative stress on your body and -- but you don't want too much of it.

  • 12:19:53

    NNAMDICare to add anything to that, Tod Cooperman?

  • 12:19:56

    COOPERMANNo. I mean, that's correct, and that's why, you know, there was a famous study a few years ago with vitamin E, an, you know, well-known antioxidant where they actually stopped the study because, you know, people who were dying at a higher rate were taking it. So, again, too much of a good thing is not good. You know, I think one of the most important things I learned in medical school was, you know, do things in moderation. And that kind of applies to a lot of things in nutrition as well as life.

  • 12:20:26

    NNAMDIWe got an email from Melissa in Missouri, who said, "My husband took our son to an alternative medicine practitioner who had prescribed an oral spray that made several claims curing hyperactivity, shyness, reading issues in adults and children as young as six months old. As I read the list, I wondered why shyness and reading issues would be a problem or even noticed in a child as young as six months old. I saw that the supplements listed on it was in 1,000 percentage of the RDA.

  • 12:20:55

    NNAMDI"I worried about possible overdose poisoning on this. I called a poison control hotline and read the information off to them even though the percentage was listed in the 1,000 percentages. The poison control nurse said that the actual amounts listed were not any -- not even anywhere near 20 percent of the RDA. Even though it said RDA percentages, it was actually made-up percentages." Any indication of how frequently something like that occurs, James Hamblin?

  • 12:21:24

    HAMBLINWell, I think a lot of these supplements that might be sold at alternative medicine stores, practitioners, might not have been through sort of regulated process that quantifies how much is actually in there and how much it relates to the RDA. So…

  • 12:21:43

    NNAMDIThey can make any claim at all.

  • 12:21:44

    HAMBLINI think so. Yes.

  • 12:21:46

    NNAMDITod Cooperman, can you respond to that and explain why the -- why can't the FDA regulate supplements?

  • 12:21:53

    COOPERMANYou know, the FDA can only kind of react to problems that exist in the marketplace. They don't have the right to take things right off the market. They need to get court orders if things get really bad. So bottom line is you really can't count on the FDA to be policing anything in the supplement market. Even DMAA, which may have led to the death of some people in the military recently and others, it took them months and months and months to get that off the market.

  • 12:22:24

    COOPERMANAnd even now, it's really being done by request. So you just can't -- the way things are, you can't count on the FDA to take action. You need to be proactive. And that woman or whoever wrote in about that product for their child, yeah, I would be concerned as well, you know? And one other thing, you know, with supplements is it's best to try to stick to a single ingredient if possible 'cause you want to know whether that's working or not.

  • 12:22:55

    COOPERMANYou don't want to be jumping right into something that has many, many different ingredients, you know, kind of a kitchen sink approach. You know, although that sounds attractive, perhaps, to a consumer, it's really not the best way to go.

  • 12:23:08

    NNAMDIOn now to Tara in Annapolis, Md. Tara, you're on the air. Go ahead, please.

  • 12:23:14

    TARAHi. Thanks for taking my call. So my question is: I'm a lacto-ovo vegetarian. So often, I am asked whether or not I get all of the vitamins that I need and if I'm deficient in anything. And I know that one vitamin -- at least my understanding -- that is found in meat is B12. And so I read in a yoga journal that it's really best to take B12 in a liquid form, and it's really great for energy. So I'm just wondering what your thoughts are on that.

  • 12:23:43

    NNAMDIWe also got an email from Emily, Tara. Emily writes, "I'm a vegan and take a B12 supplement because the RDA for B12 is so tiny, I think, six-millionths of a gram. It is all but impossible to find doses which are not, for instance, 16,670 -- 670 percent of the RDA. Given your panel's comments that taking doses much higher than 100 percent of the RDA is problematic, can they recommend on whether that applies to B12?" Know anything about that, Tod Cooperman?

  • 12:24:13

    COOPERMANSure. And, you know, it's true. B12 is one of those things what you really might want to consider a supplement, especially if you're a vegetarian, vegan or if you're over the age of 50, which applies to a lot of people. Because over the age of 50, you reduce your ability to absorb, at least, I think about 30 percent of people have a reduced ability to absorb B12 from food. So it is recommended to get it from a supplement. It is hard to find supplements that have small amounts of B12.

  • 12:24:45

    COOPERMANBut the nice thing -- the fortunate thing about B12 it's not one of those vitamins where if you get a little bit too much, it's dangerous. You can actually get a lot of B12. It's not going to be dangerous. So even if you're taking something that has several times more than you need, it's OK with B12. You know, many multivitamins, however, if you look at for multi that has very modest levels of ingredients, you know, 100 percent and not more than that of the daily value, you'll get B12 at a very modest amount. So, again, B12 is fine to take as a supplement.

  • 12:25:20

    NNAMDITara, thank you very much for your call. We have time for Andrew in Easton, Md. Andrew, your turn.

  • 12:25:28

    ANDREWYes. I had a question on a couple of different supplements. I'm 53 years old, and I take creatine occasionally to assist in working out at the gym. And I also wanted to get your opinion on testosterone supplements. Thank you.

  • 12:25:42

    NNAMDIJames Hamblin.

  • 12:25:43

    HAMBLINI would not be taking testosterone supplements without the overview of a physician. And creatine, I'm not well versed in the literature. But I don't know of proven effects.

  • 12:25:55

    NNAMDITod Cooperman.

  • 12:25:57

    COOPERMANYeah. We have reports on all of these supplements on And regarding creatine, you know, creatine, really, the only benefit is for people doing very strenuous, very intense, repetitive athletic performances like a sprinter, weight lifter, you know, in competition. It's not going to help the average person. It's probably a waste of money. And there are some creatine products we've found over the years that don't even have creatine.

  • 12:26:29

    COOPERMANSo you might want to look at that report on And in terms -- I agree with James in terms of testosterone. In fact, the supplements that are out there really don't have testosterone anyhow. They typically have amino acids which may boost your testosterone level very little bit. Really, you'll get a better boost from a good sleep.

  • 12:26:50

    NNAMDITod, what's the best way for people to find out more information and do their research on supplements?

  • 12:26:55

    COOPERMANWell, we're here to really do just that at It is a membership-based organization. So we have -- there is a $33 annual fee to be a member to get all of our reports. But we do cover from soup to nuts all these supplements, and we're out there testing them to find out and let people know which ones are really better quality and which ones are not.

  • 12:27:17

    NNAMDITell us a little bit about your testing. Consumer Lab does research and testing on vitamins and supplements.

  • 12:27:22

    COOPERMANRight. So we're out there buying products, just like any, you know, the people listening at, you know, the supermarket, the health food store, doctor's office, bringing them into the lab and testing them to see really what's inside them in terms of the active ingredients, contaminants, whether the pills would break down properly. We find that about one out of four supplements don't meet all of these criteria.

  • 12:27:44

    NNAMDIIt's my understanding that you can also get good information at The National Institutes of Health site, NIH, under the Office of Dietary Supplements, so you can go there. Tod Cooperman is an M.D. and president of Consumer Lab, which is an independent testing organization for health and nutritional products. Tod Cooperman, thank you for joining us.

  • 12:28:03

    COOPERMANYeah, Kojo, thanks for having me on.

  • 12:28:05

    NNAMDIJames Hamblin is health editor for The Atlantic magazine. James, thank you for coming in studio.

  • 12:28:10

    HAMBLINThank you for having me.

  • 12:28:11

    NNAMDIGoing to take a short break. When we come back, in the wake of the Trayvon Martin verdict, the social science research behind unconscious bias and stereotypes. I'm Kojo Nnamdi.

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