Professor Rachel Neale:

Thank you.

Clare Blake:

They’re pretty essential vitamins for the body, aren’t they?

Professor Rachel Neale:

Absolutely. Without vitamins, we can get very, very, very sick. So things like lack of vitamin C causes scurvy, lack of vitamin B causes all sorts of different problems in the body. And so there’s lots of vitamins and minerals that we definitely need and can’t do without.

Clare Blake:

And we should be able to get them through our normal diet. Is that right?

Professor Rachel Neale:

Absolutely. So, a healthy diet that contains the food groups that are recommended that we take, that we consume, definitely should give us all of the vitamins and minerals that we need.

Clare Blake:

Why have we gone so crazy for supplements?

Professor Rachel Neale:

We have gone completely crazy for supplements. And in fact, my children know that it’s not safe to walk into a pharmacy with me because I look at what’s on those shelves and get on my soap box and have a little rant largely because I think that people are looking for a magic fix. We want to be able to take something that makes us feel better, makes us live longer, makes us stronger, all of those different things. But the reality is that there’s very little evidence that any of them do that and what we really need to do: healthy diet, physical activity, enough sleep, some good friends. And those are the things that are going to actually do those things for us. So that’s the first thing, I think is what people want. The second thing is I do think there’s been a very, very good marketing machine around this to convince us that we need these things to keep us healthy.

Clare Blake:

I mean, in the past we would have been tired because we didn’t get enough sleep. And now it’s because we require a supplement.

Professor Rachel Neale:

Yeah, that’s right. So, we’re being told that there’s a fix for all of those things. So you’re tired. That must be because you’re deficient in your B vitamins. You’re, you’re lacking in energy, take a Berocca. It’s all of those things that we’re told will make us feel better and I do think it’s a very good marketing machine. And I think it’s really interesting that people are often very skeptical about big pharma. We often hear people talking about the pharmaceutical companies that produce the drugs that our doctors prescribe us and how there’s some sense that there’s a conspiracy to sort of make us sicker. Yet the big vitamin companies have got our best interests at heart? Like, they’re there to make money. So I do think there’s been a very, very effective marketing machine happening. These supplements definitely play a role. Don’t get me wrong. We need them, but marketing them to those of us who are essentially pretty healthy is not necessary.

Clare Blake:

And big pharma have much stricter guidelines as well, don’t they? Where the vitamin companies can say “clinical evidence shows” and that could be a physio clinic with three or four people present.

Professor Rachel Neale:

Yeah. One of the real challenges is that, so as you say, for the big pharmaceuticals, they have to have a huge amount of evidence around them before we’re allowed to sell them in Australia and before our doctors are allowed to prescribe them. The rules and regulations around listing these supplements are much lighter. So they don’t have to have the big randomised control trial evidence to show that these things are beneficial and they get around it by putting some fairly weak claims on their labels so that they can’t be stung for giving incorrect evidence. But I would really like to see some tighter requirements around what we’re allowed to sell in Australia. I’d like to see more proof.

Clare Blake:

So you’re not happy with “may support heart health”?

Professor Rachel Neale:

No, I’m not. I like to think of vitamins and all supplements in sort of two groups. There’s the ones that people take because they just make them feel better. And to be honest, if you’re taking something and it makes you feel better, then carry on. I don’t have a problem with that. And if it’s being marketed as “this might make you feel better”, I’m fine because it might actually make you feel better. The placebo effect is incredibly powerful. It’s really powerful. Our brains talk to our bodies in a multitude of different ways. So if you’re taking something and it makes you feel better, it may be the placebo effect, it may not, but carry on. Whereas if you’re being marketed something to stop you getting some particular illness in the future – so if you’re being sold something because it’s going to stop you having a heart attack, for example – I think we need really strong evidence around that. That’s a different thing. And I really feel like we should be saying, “you’re not allowed to sell something to stop you getting colds and flu or to stop you having a heart attack, unless you’ve got really strong evidence that it does that”.

Clare Blake:

That’s one danger. What about the other danger of a possible overdose?

Professor Rachel Neale:

Yeah, look these things can cause overdose. Most of them, you have to take a lot to cause an overdose. But I think one of the things is that we tend to assume that because they’re so-called natural, they don’t have harms. A really good example, for example, is people taking hormone replacement therapy versus the natural alternatives and assuming that because it’s a natural alternative, then it won’t have harm. Well for it to be having any benefit, it’s having an effect on the hormones in your body, and that therefore means it can have harms, but we don’t know what those are. They haven’t been studied anywhere near well enough. Whereas the HRT that your doctor is prescribing you, we’re pretty confident that we know what the harms of that are. So just because it’s natural doesn’t mean that it’s harmless.

Clare Blake:

Well looking at other research that’s been done, not by the vitamin companies, but researchers like you, is there evidence there that supplements do provide a benefit?

Professor Rachel Neale:

If you’re deficient, absolutely, supplements provide a benefit. But for the general population of people who are not deficient, there is very little evidence that taking a supplement is of any benefit. Occasionally we see a little study that pops up that shows something, but then there’ll be several other studies that show that it doesn’t do anything. So on balance, the weight of evidence shows that you’re probably just getting expensive urine.

Clare Blake:

What about specifics. Can you talk about specifics like folic acid for pregnant people and maybe iron supplements?

Professor Rachel Neale:

Yeah, so folic acid is actually a really good example and probably one of the exceptions where there is really strong evidence to show that taking folic acid in women who are planning to become pregnant or who are in the early stages of pregnancy does reduce the risk of neural tube defects in their babies. So that’s one of those situations where we’ve got strong evidence around that and the guidelines that suggest that women should take a supplement should be adhered to. 

 Clare Blake:

If you’re doing the lead up to pregnancy, that’s something your doctor will tell you about anyway – you don’t have to come up with that just by scouring a supermarket or a chemist, do you? 

Professor Rachel Neale:

Your doctor will definitely advise you about what you need to be doing in that situation, yeah, for sure.

Clare Blake:

Rachel, you actually are one of Australia’s leading experts on vitamin D. Is it actually a vitamin?

Professor Rachel Neale:

No, it’s not. It’s a bizarre thing that we call it a vitamin, but by definition, a vitamin is something that we have to get from external sources like food, whereas we make vitamin D very efficiently by exposing our skin to the sun. So it’s called a vitamin because of the way and the sort of timing of when it was discovered, but ultimately it’s not.

Clare Blake:

We’re very complex human beings, aren’t we? I suppose you’ve discovered that in your research, haven’t you?

Professor Rachel Neale:

We are extremely complex. And I think the fact that vitamin D is one of those things where we can get it from food, but we can also make it through exposing our skin to the sun, makes it an unusual thing to study.

Clare Blake:

I should say at this point this information is general in nature and not personalised medical advice, so you should always seek medical advice about your personal circumstances. Rachel, can we talk about the foods that you can get vitamin D from?

Professor Rachel Neale:

Yeah, so not very many. The best source of vitamin D is oily fish. A little bit of it from animal products like eggs, but really the best way of getting vitamin D naturally without having to take a supplement is going out in the sunshine. And that makes a very difficult situation because Australia has the highest incidence of skin cancer in the world. So advising people to get some sun exposure is a very challenging problem and how to find that balance is something that there’s a lot of scientists around the world who are very interested in, and we’re still not quite there yet.

Clare Blake:

Things would have been so different for you, Rachel, if you were studying this in the ’60s and ’70s, when we were all just out there, basically naked on the beach for a whole summer.

Professor Rachel Neale:

Yeah, so we often hear people say that our sun protection messages have caused vitamin D deficiency. We actually don’t know that because people’s vitamin D levels were not being measured and reported so much back in the ’50s and ’60s and we certainly didn’t have big population-based studies to know what was going on back then. Even if the prevalence of vitamin D deficiency has increased, we don’t know that that’s due to the sun protection messages. Lots of other things have changed in the meantime. We’ve moved from being outdoor workers to being indoor workers. Our recreation has changed from being outdoors activities to a lot more inside screen-based activities. So there’s been definitely changes over time that are potentially influencing the risk of being vitamin D deficient. One thing we do seem to know is that putting sunscreen on, the best evidence we have suggests that that doesn’t actually cause you to become vitamin D deficient. So the recommendation that I always give to people is to put sunscreen on every day on your face and hands – the bits of you that are most likely to get skin cancer – but try and expose the bits of your body that don’t routinely get the sun a few times a week for a short time. So go and sit outside having your morning coffee at 11am on a Saturday morning, wearing short shorts and a singlet top for five minutes.

Clare Blake:

Do you think people will heed that?

Professor Rachel Neale:

I think that we have a fair bit of confusion about the vitamin D sun exposure story and what we should do about it. And that’s understandable because I think the scientists and doctors have been confused and still are to a certain extent. So I definitely think we’ve got some confusion around that. And as a consequence, people are either getting too much sun – so they’re lying in the sun for a long time using vitamin D as a bit of an excuse – or they’re avoiding the sun like the plague and therefore not necessarily making enough vitamin D. So I think that there’s some confusion around there and what we need to be able to do is give some clearer guidelines and we’re working on that at the moment.

Clare Blake:

And the fear of melanoma and our better education around that plays into that, doesn’t it, as well?

Professor Rachel Neale:

Yeah, and that’s definitely a real fear. I mean, we have many people affected by melanoma and other types of skin cancer every year. We cannot discount that as a risk. So we’ve got to work out a way of getting the balance between the good and bad of sun exposure.

Clare Blake:

Well, this leads me into what you’re doing now. You are running a randomised control trial, which is the gold standard in research, looking at whether vitamin D supplements provide health benefits. So part of what you’re talking about, I guess, is why you decided to start this trial.

Professor Rachel Neale:

Yeah, so one of the real challenges in understanding the benefits of vitamin D is that people who have high vitamin D levels tend to be active, outdoorsy sort of people who are going to be healthier anyway. So we don’t know whether or not it’s the vitamin D that’s important, or it’s just being healthy and vitamin D is a marker of being healthy. So one of the ways around that is that we get a large bunch of people and we essentially toss a coin to put them into one of two groups. And by tossing a coin like that, what we call random assignment, it means that the characteristics of those two groups are on average the same. So, for example, the proportion of people that’s overweight will be exactly the same in the two groups or the proportion of people that don’t go outside will be exactly the same. And then what we do is we say to one of those groups, “we want you to take a vitamin D supplement”. And in my case, I’ve said, “I want you to take it for five years”. And the other group, we give an identical-looking tablet, a placebo tablet. And then we follow those people over time to look at whether or not the proportion of people who get cancer, for example, differs between those two groups. And if it does differ, we know that that’s because of the vitamin D, because everything else about those two groups was on average the same.

Clare Blake:

The same…

Professor Rachel Neale:

So that’s why randomised control trials are the gold standard, because they even out all those other differences that you see.

Clare Blake:

You see online all the time, there’s links between cancer and everything. Is there any evidence to suggest that there’s a link between vitamin D levels and cancer?

Professor Rachel Neale:

There is, and that’s one of the reasons for doing the D-Health trial is because of those links. We’ve seen pretty consistently that people with higher vitamin D levels are at lower risk, particularly of cancer of the large intestine, the colorectal cancer. So that’s pretty consistent, but the problem we’ve got is that, as I said, the people with higher vitamin D levels are also more physically active. They’re often eating better because it’s part of that whole healthy lifestyle thing. And we know that those things influence risk of colon cancer. So that’s why a trial like D-Health will help us to untangle the importance of vitamin D for cancer. We’re also looking at cardiovascular disease, heart disease. We’re also looking at all-cause mortality – so just the rate at which people die. But we’re also looking at a bunch of other sort of more quality-of-life issues. So things like sleep quality, general feelings of wellbeing, pain, tiredness, all those things because you hear people say, “Well, when I started taking a vitamin D tablet, it made me feel better”. But we don’t know if that’s the placebo effect or not. So we’re also measuring all those things in D-Health to get a really holistic view of what vitamin D might or might not do for us.

Clare Blake:

And placebo just can’t be underestimated. I know you said before, it can be as high as 30 per cent, can’t it?

Professor Rachel Neale:

Yeah. It’s really, really powerful. And it’s a shame that we can’t use it, but it’s a bit unethical for a doctor to give someone a placebo tablet. It’s a tricky thing to harness that placebo effect. And I think that that’s one of the things that supplements kind of do, if it’s about making you feel better. And that’s why I said before that people are taking stuff – so long as it’s not harmful and it makes them feel better, [and] they’re happy to spend the money on it, then it’s fine.

Clare Blake:

Getting back to the exposure you need to get the right amount of vitamin D, Rachel, does it depend on winter or summer? Does it change?

Professor Rachel Neale:

Yeah, it does. For the whole of Australia in summer, you’re doing pretty well to be vitamin D deficient actually, because just going about your normal day-to-day activities, popping out at lunchtime to go to the shops or picking up the kids after school and standing in the playground for 10 minutes really should avoid vitamin D deficiency. But in winter it’s much more tricky because there’s not as much UV and it’s cold, in southern states particularly. So that becomes a problem. In Queensland all year round, it’s easy. And in fact, we’ve got evidence from some of my very early research that shows that – and it’s sort of not rocket science, it makes sense – that in winter, we actually stay out in the sun more in Queensland because it’s cooler. So, you imagine if you go for a picnic in summer, you sit under a tree. Whereas if you go in winter, you’re sitting outside to get the lovely warmth of the sun. So in Queensland all year round, it’s really not something you need to worry about unless you’re stuck indoors for some good reason, elderly people who can’t get out and about very much and whose skins potentially don’t make vitamin D as easily anyway. But in those southern states in winter, it can be really problematic. So one thing that you can do is make sure that you’ve got good vitamin D stores before you head into winter, because we can actually sort of stockpile it to see us through winter.

Clare Blake:

Oh really?

Professor Rachel Neale:

Yeah.

Clare Blake:

Let’s talk about the levels too, because the experts don’t even agree. I know the UK has a different level than we have in Australia about what a healthy level is. And I know that you can also get different results based on who you went to.

Professor Rachel Neale:

Yeah. Historically, the tests that are done in the laboratory to measure vitamin D have been inaccurate and imprecise, which makes it very difficult to know what level we need. And so once we establish that, if you’re having a test that’s not very accurate, then it’s difficult for your doctor to interpret. That’s improved a lot. There has been a big international effort to improve vitamin D testing. It hasn’t necessarily made it into the clinical laboratories yet, but it’s definitely improving. But as to this disagreement about what level we need, there is a lot of controversy out there. We all agree that having a vitamin D level of less than about 25 to 30 nanomoles per litre increases your risk of having problems with your musculoskeletal health. So we all agree that you shouldn’t go below that. But then as far as how high you should go, some people say, “let’s aim for 50”, which is what the Australian guidelines are because that’s going to keep most of us pretty healthy, but there are other people who say we should go to 75 nanomoles per litre. And in fact, there are some groups in the world, not government bodies, but certainly some groups in the world who suggest we should be aiming as high as 100 to 150 nanomoles per litre. So, 25 to 100, or even 25 to 75, is a really big difference in what we should be aiming for. So it’s a tricky field for us as consumers and also for our doctors to know what to do.

Clare Blake:

I know that you’re featured in Vitamania, a doco about these sorts of things and there was one person that actually overdosed on vitamin D. That’s pretty rare.

Professor Rachel Neale:

That’s very rare. It’s hard to overdose on vitamin D. It’s pretty safe. That case in Vitamania was a baby whose mother had been using drops, vitamin D drops…

Clare Blake:

…In the baby’s…

Professor Rachel Neale:

… in their baby’s milk and had, instead of putting one drop in the milk, had put lots of drops in the milk, thinking that if a little bit was good, then more would be better. But for a standard adult taking a tablet, you’d have to take a lot of them to really cause toxicity. That doesn’t mean there may not be risks. There is some evidence that taking a lot of vitamin D may increase the risk of falling in older people. So we’re having a good look at that in the D-Health trial to see if giving older people a fairly hefty dose of vitamin D increases the risk of falling.

Clare Blake:

The results of this should sort a few things out Rachel. I’m really looking forward to this.

Professor Rachel Neale:

We hope so. We believe it will. That’s the plan.

Clare Blake:

What’s your view on testing for vitamin D?

Professor Rachel Neale:

Vitamin D testing has gone through the roof. From 2000 to 2014, there was a 136-fold increase in vitamin D testing, costing the Australian Government about $100 million dollars a year – probably money that could be better spent elsewhere given that the guidelines suggest that we don’t have enough evidence to support population-based screening for vitamin D deficiency in the absence of symptoms or a really good reason to think that people might be vitamin D deficient. And even in those people who you think, “it’s highly likely that you’re vitamin D deficient because you’re housebound”, we don’t really need to test. We could just give them a supplement. It’s cheaper than testing. So that whole idea of clinical testing in the absence of a strong indication for it is a problem and Medicare have asked doctors to stop doing that. 

Clare Blake:

So your doctor shouldn’t put that in a normal battery of tests you do?

Professor Rachel Neale:

No. The rules around vitamin D testing now are that you have to have one of a list of reasons for Medicare to fund the test, but we’ve got pretty good evidence that there is still over-testing going on in our community.

Clare Blake:

If you are really deficient, then the possibility is rickets, but how common is that?

 Professor Rachel Neale:

Rickets in children is low. There are some populations where it is higher and the prevalence of rickets has been increasing somewhat. In adults, the equivalent to rickets is called osteomalacia, it’s soft bones in adults, and it can cause fractures and bone pain and muscle pain. So adults can get sort of adult equivalent of rickets, but again, it’s fairly rare and you do need fairly severe vitamin D deficiency to cause that. So the best advice as far as vitamin D is concerned, is to get a bit of active time preferably – because that’s also good for your bones – outdoors in the sunshine, but being very, very careful not to get too much, because that then increases your risk of skin cancer. So that’s a tricky one. As far as other vitamins are concerned, a really healthy diet, lots of fruit and vegetables, healthy grains, some – if appropriate, and this is a controversial issue, whether or not you should be vegan, vegetarian, and how you manage that…

Clare Blake:

Let’s not go there today.

Professor Rachel Neale:

But let’s not go down that pathway. But I think a really healthy diet without too much processed food and [with] lots of natural food is the best way to get the vitamins that you need. [For] vitamin D, some nice healthy, oily fish and some sun exposure is your best bet.

Clare Blake:

It’s brilliant to have you cut through a lot of the noise Rachel, thanks so much. That’s just a tiny insight into Professor Rachel Neale’s work. For more on Rachel’s studies, if you’d like to be a part of it, and all of our latest research, just go to qimrberghofer.edu.au. Thanks Rachel.

Professor Rachel Neale:

You’re very welcome.

back to podcast episode