Supplements claiming to “boost your immune system” have gotten new attention during the pandemic. On the podcast Social Distance, the staff writer James Hamblin explains why these claims are mostly nonsense (and have been for years), and the executive producer Katherine Wells asks him about vitamins.

Listen to their conversation here:

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What follows is an edited and condensed transcript of their conversation.

Katherine Wells: I just got a news alert: FDA withdraws approval of malaria drugs touted by Trump. Hydroxychloroquine, I assume, is what they’re talking about?

James Hamblin: It had an emergency-use authorization, which is different from the long process that is required to prove that a drug helps. If there’s some plausible reason to think it might, it gets emergency use authorization. Here, we didn’t really have that, but we did have political pressure from the president, who had touted the drug as a miracle and actually encouraged people to try it at press conferences. Then suddenly it gets this emergency-use authorization. And a lot of people—a lot of doctors and patients—said: You know what? It can’t hurt. And it might help.

They didn’t have evidence of that. But we have these sort of rose-colored glasses on. There’s an odd optimism in moments of fear, where you start to look at things that are implausible and that are not, in fact, risk-free. And suddenly it’s very easy to convince people: You know, why not try it? Why not do it?

Wells: So we know that hydroxychloroquine is not going to somehow magically protect us, and now the FDA is saying no, but you have said many times that outcomes are highly correlated with people’s general health and immune systems. So we should be doing things to boost our immune system and make sure that we are as healthy as possible, right?

Hamblin: Yeah. Actually, boosting the immune system is one of my pet peeves.

Wells: Because you don’t like the word boost?

Hamblin: Yeah, well, you don’t want to increase it unduly. We have talked about the cytokine storm, and that’s actually your immune system going way overboard.

Wells: Right, and autoimmune disorders.

Hamblin: Yes, exactly. Those are treated with immune-suppressing drugs, of which hydroxychloroquine is one. We’re talking about a sort of balance and equilibrium that we’re looking to achieve.

Wells: I’ve been taking a multivitamin every day because I’m like: I don’t know. Couldn’t hurt. But you are a multivitamin skeptic for reasons that I don’t remember or understand. What’s wrong with taking a multivitamin? Isn’t that just good if you need it and not bad if you don’t?

Hamblin: I think that’s generally true. It’s probably fine. Depending on if you’re taking a lot of other vitamins and supplements with it, there’s a potential with some vitamins that you can get too much, but most likely these vitamins are balanced such that you’re not going to have too much of anything. But what I’m interested in is that same fallacy I’m worried about with hydroxychloroquine: a false sense of protection.

It’s been my experience that when I have taken multivitamins, I feel some sort of Maybe I don’t need to eat quite as well. A lot of people feel that you can maybe just, like, have a pizza and a multivitamin, and that means you’re full up on all the things you need.

But it’s not the same. It doesn’t work. It would be amazing if you could replicate a healthy diet in one pill a day, but we’re so far from that.

Wells: What is the point of a multivitamin then? Why does it not work?

Hamblin: There is something to the actual structure of food. It contains fiber. It sends a signal to your gut simply by its volume. We have not been able to, in medical science, replicate the act of eating real food. When people have to have feeding tubes of different kinds of emergency nutrition, it’s never as sustainable as when you’re actually eating “real food.”

Wells: Right, but there have been studies that show that people who wear safety gear are more reckless, and we still tell people, “Wear a seat belt and a helmet,” so why not take a multivitamin?

Hamblin: If you can add a multivitamin and not change anything, then go for it. Whatever. I mean, you might waste your money.

Wells: Is there really no science behind a vitamin being good for you?

Hamblin: Not unless you have a deficiency in any of those areas.

Wells: And do people generally have deficiencies? Does our modern diet mean you have some deficiencies?

Hamblin: No, you need so little. And anything that you would be likely to get deficient in, we fortify. Even pastas and cereals, they’re fortified with vitamins in case you do just eat packaged foods all the time and never eat fresh produce.

Wells: You’re telling me that, like, my Cheerios have a multivitamin in them?

Hamblin: Oh, yeah. They’re loaded with vitamins. The reason there’s vitamin D in milk is because we add it to the milk. We found ways to make an ultra-processed diet that would avoid vitamin deficiencies. And that’s actually a problem for us.

Wells: So our diet is already basically the equivalent of a multivitamin, where we’ve just randomly put vitamins in the crap we eat?

Hamblin: That’s what fortification is. It’s one of those things that is sort of like oxygen. You are getting enough and getting more is not going to help you. The one outlier in the coronavirus-vitamin discussion is vitamin D. There’s almost nothing in our diet that gets us vitamin D. It shouldn’t even be called a vitamin, in my humble opinion.

Wells: What is the definition of a vitamin?

Hamblin: There is no definition. It’s derived from this marketing term, vital amines. We thought they all had an amine group on them and turns out they don’t.

Wells: That’s what “vitamin” is?!

Hamblin: Yeah. A great book on this is Vitamania, by Catherine Price. It goes into the whole supplement industry and how these ideas started.

Wells: What are vitamins?

Hamblin: It’s a random smattering of compounds. We call them “micronutrients,” as opposed to, say, macronutrients like fats, carbohydrates, and proteins. “Micro-” nutrients are these tinier ones, which you need, like, the amount of the head of a pin every month. Most of them occur in food. Vitamin D is one that doesn’t. You make it yourself being out in the sun. And you don’t need a lot, just a few minutes.

There is not evidence that laying out and tanning is good for you. That’s still a major cause of skin cancer. As long as you have some exposure, even just sitting near a window, that should be fine. But there are some serious researchers who believe that there are people who are in a gray area, who might not be getting enough vitamin D, especially when told to stay home. When you’re really limiting outdoor exposure, it could be good to take a supplement.

Wells: So it’s not that vitamin D somehow fights off the coronavirus. It’s that if you don’t have enough vitamin D—and there could be a slightly elevated percentage of people who don’t have enough vitamin D, because we’re all staying inside a lot—then your immune system can get all wacky, and therefore you would want to take a supplement. What about vitamin C? At the beginning of this, I was taking a vitamin C supplement every day.

Hamblin: Do you know why people think vitamin C helps with colds?

Wells: I do not.

Hamblin: So, Linus Pauling was a Nobel laureate, really respected. Albert Einstein said of Linus Pauling’s work: “It was too complicated for me.” This was back in the 1930s. Pauling did a lot of groundbreaking physics and became the world’s eminent scientist. And then, in his later years, he started getting really, really into vitamin C in a strange way. He took tons of it. He started becoming an evangelist for it, and it was strange because he really was as respected and credible as anyone could be in a scientific field.

And people tested his theories that it would prevent cancer and all sorts of diseases, and it didn’t bear out. Vitamin-C supplements will not protect you and will not improve the course of respiratory illness. There is a smattering of bad evidence but no good evidence, and the only reason that people believe it in the first place is this historic fallacy that did not bear out from a person who ended up basically losing all of his credibility by the end of his life.

Wells: What about orange juice? It’s completely marketed on vitamin C.

Hamblin: And it’s just sugar. Juice is one of the worst things you can drink. We know that getting too much sugar is not good for you. And we know that consuming it in the form of an orange versus orange juice is simply better because we at least get some fiber in it. It moves through your system more slowly, absorbs it more slowly, whereas juice is just like Hook it into my veins. I don’t recommend drinking orange juice.

Supplements are an enormous and almost unregulated industry. They are marketed as parts of all these foods in all these other industries, like orange juice, dairy, cereals, and all these things that, just because it says “Now with extra vitamin E,” you’re supposed to just believe that must be good. And despite the lack of evidence to support it, we also have this bias of thinking: Well, I think it’s good. And even if I’m wrong, it can’t hurt, right? And that bias is so strong when it comes to things like life and death. Anyone with any concern about their longevity or management of chronic illness is very susceptible to that reasoning and logic. And it’s very sad to see.

With vitamins, and with hygiene-ritual products, it’s important to allocate the things that you believe are protecting you, or that you enjoy, and just make sure they really are things to protect you, or they really are things that add value and joy to your life. And if they’re not, then get rid of them.

Wells: That’s really good advice. I think I’m going to keep taking the multivitamin every now and then just, you know, because it can’t hurt. But also, every time I take it, I’m gonna be like, I’m being had.

Hamblin: You got me, multivitamin. Down you go. The vitamin-C supplements specifically. They’re allowed to say things like “Enhance immunity” or “Boost immunity.” They are not allowed to make specific medical claims, like saying “Prevents coronavirus infection.” But I’m already seeing that stuff pop up all over, you know.

Wells: Wait, but “Boost immunity”—you’re saying that is false?

Hamblin: Right, but they can make those claims. The supplement industry has an enormous lobby and has been basically unable to be regulated. They tried to regulate it back in the ’80s and there was a huge campaign in response. The lobby got to Ronald Reagan and was like, Don’t let the government take over your vitamins. And then Congress just let it go.

There is a commercial that was funded by the vitamin industry with Mel Gibson. Government agents come into his house to take the vitamins out of his cabin.

Wells: Oh my God. If Mel Gibson was involved, like, red flag.

Hamblin: It’s sort of this wild west of compounds, where you can take anything to market right away. You’ve got to notify the FDA, and then you can start selling something and calling it vitamin D. Versus the pharmaceutical industry, where it’s a long, enormous, expensive process where you have to actually prove that it does what it says it does.

Wells: That brings us back to where we started this conversation: the FDA actually preventing something peddled as a hopeful cure. But we’re still all drinking fizzy orange liquid.

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