Multivitamins: Are they a scam?

Tegan Taylor: Hello, Norman.

Norman Swan: Hello, Tegan.

Tegan Taylor: You know when you're making a cake and the cake turns out like a little bit…there's holes here and there, it's a bit dippy in the middle, and you just slather it with icing, and it looks fine from the outside because you just fill in all the gaps with icing?

Norman Swan: I do know that, and sometimes they're the best cakes because it's all squashy in the middle.

Tegan Taylor: That's what I think too. I used to have that approach to taking a multivitamin. When I was in my 20s, I was, like, well, you know, I eat veggies most of the time, blah, blah, blah, but just in case, just to smooth things over…

Norman Swan: So the vitamins were the icing.

Tegan Taylor: …were be icing and the cake was my diet. And most of the time I think the cake was probably fine, but, just to be sure, I slathered that multivitamin over the top.

Norman Swan: Well, I think your success in life can all be put down to multivitamins.

Tegan Taylor: Short episode. That's it, that's the question, that's the answer. No, no, we do need to talk about it properly today.

Norman Swan: Because you are listening to What's That Rash? where we answer your questions on health and wellbeing.

Tegan Taylor: I'm health reporter Tegan Taylor. I'm on Jagera and Turrbal land.

Norman Swan: And I'm physician and journalist Dr Norman Swan and I'm coming to you today from Gadigal land.

Tegan Taylor: And Liz is asking, surprisingly, about multivitamins. She says: 'I'm an average woman with an average normal diet and average normal lifestyle.' Good on you, Liz. 'I don't have any specific health issues. Should I be taking any regular multivitamins or other vitamins? The pharmacy has a whole aisle of them. Is it all a scam?' So Norman, let's talk today about multivitamins specifically.

Norman Swan: Yes, okay. Thank you very much, Liz, for that question. We're getting really noncontroversial easy questions on What's That Rash?. We should probably call it What's That Scam? because that seems to be a theme over the last couple of weeks.

Tegan Taylor: Well, I know that you love talking about how most of the stuff that's sold in pharmacies isn't evidence based, so why not, why not just dig straight in today!

Norman Swan: Well, the other thing that I commonly say is that Australians have the most expensive urine in the world. Which gives you a flavour of what I think about multivitamins.

Tegan Taylor: I don't want 'urine' and 'flavour' used in the same sentence, thank you. I think what we should do is talk about multivitamins, because that's kind of a question and it's also the way I used to make my diet cake. What's usually in a multivitamin that you can get in a supermarket or pharmacy in Australia?

Norman Swan: Well, it's hard to generalise. But basically there's a few vitamins and there are almost certainly some minerals as well. So I'm just giving you an example of one which probably is not that unusual, where you've got retinol, which is a form of vitamin A, beta-carotene, you've got vitamin D3, then you've got some antioxidants, lutein and lycopene, some calcium, some thymine, nicotinamide, so basically a few vitamins. And then there's some minerals, calcium, magnesium, iron, zinc, manganese, and that sort of thing, micronutrients, selenium, they're pretty popular. And so I think that's what you get. So it's not a multivitamin, it's a multi-element supplement is what usually is in a multivitamin.

Tegan Taylor: Oh, that's not quite as snappy as the word 'multivitamin'.

Norman Swan: No, it's not. And they tend to tailor…you know, you can have it for women, you have it for men, you can have it for kids, they manipulate the recipe.

Tegan Taylor: So it's a catch-all term, but there's not really like a standardisation in Australia.

Norman Swan: No, I mean, and why should there be? There's a multivitamin, it just means that there's many vitamins in it. And as long as there's vitamins in it, it would qualify to be a multivitamin.

Tegan Taylor: So obviously, in different times in human history, and in certain parts of the world, nutrient deficiencies have been a big problem and can cause big health effects, can cause birth defects in babies. But how much of a problem is nutrient or vitamin deficiency in Australia? Like, for the most part, we have a fairly stable food supply, we have a fairly varied diet.

Norman Swan: Maybe just before we get onto that, the history is quite illuminating.

Tegan Taylor: Oh, well, it does include a character called Dr Funk, so we do need to talk about the history.

Norman Swan: That's right, and you shouldn't get into funk about Dr Funk because…

Tegan Taylor: No, he's funky, I love him.

Norman Swan: He was a pretty good biochemist. But it comes to your issue of deficiency. So he essentially discovered vitamins by looking at very specific deficiency patterns like beriberi, pellagra, scurvy, rickets, where you had a syndrome, and he suspected that there was a substance lacking in the food of those people, and then he investigated it. And he uncovered that there were B vitamins deficient, rickets of course is vitamin D, and others, so he didn't discover all the vitamins but essentially he found a way of discovering the vitamins that caused a specific vitamin deficiency pattern.

Now, we don't see those patterns in Australia. There's been some rickets in kids born to African migrants, women who have come from countries where they're used to exposing their skin to the sun and getting vitamin D. But when they live in small apartments in Melbourne, and they've got their heads, their bodies covered when they go out, they are vitamin D deficient. So we have seen that a little bit. But scurvy, maybe the odd case in elderly people. But by and large we don't see deficiency diseases.

Tegan Taylor: So, what's the point of a multivitamin, at least the vitamin parts of it, when we're not really having people be deficient anyway?

Norman Swan: Well, that's the key question. And all I can do is quote you the people who promote multivitamins. They say, well, there are subclinical deficiencies, meaning, it's so subtle you can't notice it but you should actually replace it, and that the recommended daily requirements as published are actually not enough for some people, because you might be exercising or you might be doing this, that or the other and you need a little bit of extra boosting from the vitamins.

Tegan Taylor: So that's what the companies making these vitamins say, and you do sort of hear that marketing of putting a spring in your step or giving you some vigour or, like you say, if you're a really active person, you've got a busy life, that these vitamins can do that. On the backs of the packets they'll often have the RDI, the recommended daily intake, or a percentage of that. Where did those numbers actually come from?

Norman Swan: So there's a bit of a history to recommend a daily intake. A lot of the requirements for diet emerged…it was British nutritionists who started to find, when you were going into rationing and wartime, what did people actually need? And they extrapolated from the deficiency diseases that we saw in poorer countries and the work of Funk and others, and essentially they've added to that over the years and concluded what might be the recommended daily intake of given vitamins, and then extrapolating from animal studies. There is one big caveat to all this, when they're talking about recommended daily intake, they're talking about it from food, they're not talking about it from a bottle. And when you have it from a bottle, you're actually no longer taking vitamins, you're taking drugs.

Tegan Taylor: That's a spicy comment. What do you mean?

Norman Swan: Vitamins are taken in tiny, tiny amounts into the body in food, with all sorts of other substances in the food which help the vitamins and other micronutrients to be absorbed and utilised. So they're actually tiny amounts. And when you start giving more than tiny amounts, you're not necessarily getting the same effect that you would from the recommended daily intake and taking more might not be better. And I think I've spoken about this before on What's That Rash?, vitamin C in food in low doses is an antioxidant, it slows down the oxidative stress, the internal body rusting that's associated with ageing and premature ageing. However, vitamin C in high doses (and nobody knows really why) is a pro-oxidant, it speeds up oxidative stress.

Tegan Taylor: Oh, that's sad, because that's the one vitamin that actually is yummy. The vitamin C tablets are good.

Norman Swan: Because of the taste of them, yes. Well, to the extent that people are starting to look at whether or not you could use vitamin C as an adjunct to chemotherapy, because it helps to kill cells.

Tegan Taylor: Yeah, good in chemo, not really good in any other application.

Norman Swan: Well, that's right. So that's the whole issue here with multivitamins.

Tegan Taylor: So if you're getting more than you need, what happens to that excess vitamin in your body? You mentioned expensive wee before, which I assume means it just gets excreted in your urine, but not all of them just get excreted in the amounts that you don't need.

Norman Swan: So you've got the water soluble vitamins, particularly vitamin C, vitamin B, the B vitamins, and they get peed out but also they do accumulate in your body, they can cause toxicity at higher levels before they get peed out. So in other words, it doesn't mean that they don't accumulate in your body. Then there's the fat-soluble vitamins, some of which, like vitamin A, can accumulate in your body and really cause quite a lot of damage if you take it in excess quantities. And then there's the one particular form of vitamin B, vitamin B6, if you take it in high amounts it can damage your nerves permanently, cause peripheral neuropathy.

Tegan Taylor: Oh, wow. And so if you're getting this bad effect from the vitamins as a supplement, do you see the same effect if you're eating a lot of foods that are really high in these vitamins?

Norman Swan: Remember, the safety margin on most of the vitamins and most multivitamin tablets is pretty good. Even for vitamin B6, the TGA has been quite strict on controlling that but you've got to watch if there's vitamin B6 in a multivitamin tablet. So, for example, let's just take people who are vegan. People who are vegan run the risk of (probably less of a risk now than years gone by because there's so many vegan products on the market) becoming vitamin B12 deficient. Now, B12 has actually quite a big safety margin if you're taking vitamin B12, a much bigger safety margin than vitamin B6. But it's all different, you can't generalise. But most multivitamins, taken reasonably, are not going to do very much harm, if any harm at all. Are they going to do you any good, though? So coming to your question about food, unless you've got a particular food obsession, it's very hard to take too much in food, because you get full up before you come anywhere close to it. It's a bit like the equivalent of taking fruit juice versus whole fruit; it's much easier to swallow a glass of juice than it is to eat four oranges.

Tegan Taylor: Yeah, exactly. So my overall impression, Norman, is that you are a little dim on multivitamins. Is there any evidence to support them?

Norman Swan: There's a little bit but it's quite specific. So for example, there's been quite a good randomised trial done with good researchers, Harvard based researchers, looking at dietary flavonoids, those are antioxidants, and also multivitamin preparations, to see whether it has an effect on memory. And what they found was that in people with poorer quality diets they did see some improvement in memory. But in people who are reasonably well nourished, they didn't see pretty much any benefit at all.

The strongest evidence is actually in macular degeneration. So macular degeneration is a genetic disease at the back of the eye, the retina. And if you look at nutritional intake of large populations, the populations with the healthiest diet and the highest intake of antioxidants seem to have the lowest rate of age-related macular degeneration. So eye surgeons around the world said, well, what happens if we actually supplement with antioxidants? So to summarise the studies, there is a mix of antioxidants called AREDS2, vitamin C, vitamin E, and zinc and copper. And that seems to reduce the risk of macular degeneration in people who are at high risk, and it seems to slow the progression of some forms of macular degeneration, if they're put onto this early enough.

And because they've done these large-scale studies, giving particularly older people these multivitamins, they've also looked at some of the other benefits such as does it prolong your life? The answer is no. There's no evidence that multivitamin preparations prolong your life, make you live longer. And there is some risk, so beta-carotene, if you've been a smoker, it increases your risk of lung cancer. So in AREDS formulations for macular degeneration, they've tended to remove beta-carotene, and replace it with other antioxidants.

Tegan Taylor: So, a fair few caveats there, it sounds like there is a basis for some very specific formulations of antioxidants for some very specific reasons. But to come back to Liz's question, for that average woman, average normal diet, average normal lifestyle, is there any benefit at all in taking multivitamins?

Norman Swan: Save it up for the kids' birthday presents. Seriously, you're not going to do yourself any harm, you're almost certainly not going to do yourself any good at all, but you're taking something you just don't need to take. Because if you take a highly varied diet, very diverse in vegetables, not too much red meat, then you're going to be getting very potent forms of these antioxidants. You cannot buy in the chemist an antioxidant that's as powerful as the antioxidants you get in tomato or capsicum when you sprinkle olive oil on them and grill them.

Tegan Taylor: And I can tell you they're a lot tastier than swallowing a pill.

Norman Swan: They are.

Tegan Taylor: Liz, thank you so much for your question. And if you have a question, you can send it to us, thatrash@abc.net.au, which is also where you can write to us with things that aren't questions, like Kim has. Kim has written in, Norman, off the back of our chat about chiropractic. And Kim said they had 20 years persistent back pain, had gone to a physio, gone to a deep massage place, finally went to a chiropractor and was quite nervous and ended up coming away pain free after three treatments. And it was Kim's massage therapist who recommended that they try chiro, and he lost a customer by doing it.

Norman Swan: Well, some chiropractors pride themselves in saying, 'If I can't help you, I'll tell you, and I'm going to try and get you better in two or three sessions. You're not going to have to come to me for life.' And this is called the Gonstead method I think is what Kim had, where they carefully assess you, and they're trying to do it in a minimum number of sessions. So they're not trying to keep you as a customer for life.

Tegan Taylor: They're doing themselves out of a job. We also got an email from Ian who is listening from Sweden. Hello, thanks very much. Ian sent us a link to an Ig Noble Prize from 2009, there was a doctor Donald Unger who received the Medicine Prize for cracking the knuckles of his left hand only, not his right, for 60 years to see if the habit contributed to arthritis.

Norman Swan: A non-randomised but controlled trial…

Tegan Taylor: A very controlled trial.

Norman Swan: So was his left hand limp and useless?

Tegan Taylor: No, it was the same. No, it didn't contribute to arthritis in his left hand.

Norman Swan: Well, he deserves an Ig Noble for that.

Tegan Taylor: So crack away, folks. And be like Kim and Ian, send us an email and tell us if you're still going to take your multivitamin or if Norman has single-handedly put the pharmaceutical business in Australia out of business, thatrash@abc.net.au.

Norman Swan: And if you've got your own concoction, do let us know, we'd be fascinated. You know, have you combined your multivitamin with cracking your knuckles and did that make a difference?

Tegan Taylor: Do you know, I actually have concocted my own multivitamin, Norman?

Norman Swan: Oh, have you?

Tegan Taylor: It's called a salad.

Norman Swan: Followed by a heavily iced sponge cake.

Tegan Taylor: Exactly.

Norman Swan: We'll see you all next week.

Tegan Taylor: See you then.