A little bit of sunshine – MS and Vitamin D

MS Plus acknowledges the traditional custodians of the land this podcast is recorded on, the Wurundjeri people of the Kulin Nation. We pay our respects to their elders past and present.

This is the MS Boost, the stuff you need to know from the people who know it.

Jodi: Hi and welcome to MS Boost. My name is Jodi Haartsen, and we are super excited to be speaking to Dr. Wei. Dr. Wei is a neurologist and scientist at possibly the largest research center and clinical service in the Southern Hemisphere at the MSNI Clinic at Alfred Health, and they have a huge different areas of interest in research but one that particularly spiked my interest and I wanted to chat to Dr. Wei about today was vitamin D.

I know as a nurse for the last 20 years, we kind of all made this assumption that because people lived further away from the equator that they're more likely they were to have MS. So that must have had something to do with the sun and we know that vitamin D is involved in the immune system. So, I guess we kind of seem to make assumptions that vitamin D had something to do with MS. And like all good scientists and researchers, the team at MSNI and Dr. Wei, in particular have challenged those assumptions that we've made and discovered a lot more about the role of vitamin D in MS and more questions and hopefully some answers.

So, tell us about how you got interested in vitamin D research in the first place.

Wei: Yeah, thanks Jodi for giving me the opportunity to speak to you today. I think when I was growing up, I was always interested in how things work. And then later on in my medical training, I was very intrigued by how the immune system can do the wrong things and therefore cause various types of autoimmune disease.

And now I'm a neurologist and also a researcher I've got a particular interest in Multiple Sclerosis and see people with MS in our neuroimmunology clinics here at the Alfred as well. And I think although our understanding of MS has certainly improved significantly over time and including now having of course available to us these very effective treatments which work very well at preventing inflammation and therefore injury to the brain and spinal cord. There certainly are still many unanswered questions and as you say, Jodi, one of these things is the role of vitamin D. Studies have pretty shown clear links between vitamin D deficiency and the risk of developing MS, but the specific mechanisms and ways that vitamin D affects the immune system in the context of MS are not well understood. And so, I was interested to see if we could gain some insights into this and that formed a large part of my PhD, which was studying how vitamin D might affect the immune system.

Jodi: So, you started your journey with vitamin D, quite a few years back, but your more recent studies looked at the relationship between genetics and vitamin D.

Can you tell me how did that pathway progress when you were looking at vitamin D? Did you have any moments where in your early research where you went, ooh, wow, this is where we want to go. How did that happen? What understanding have you grown?

Wei: Yeah, so as you say a number of studies was only looking at vitamin D as an overarching theme. And in the context of my PhD and the projects I worked on we specifically focused on how vitamin D might affect or how it's associated with the expression of genes in immune cells. And to start off with some background and to set the scene, so our cells in our body each have copies of DNA. Which can be thought of as our cell’s instruction manual or a recipe book and genes can be thought of as each individual recipe, with a number of these genes or recipes being the instructions on how to make proteins which make up our body. And so, we looked at the number of times each gene is read or expressed and that gives us a sense of how much protein is being made. In the first study in my PhD that looked at vitamin D we compared how vitamin D levels correlated with gene expression in different types of immune cells in those with MS and also those without MS. And we found that these correlations with vitamin D were more prominent in those without MS than those with MS. And so, this observation suggested that the response of the vitamin D might actually be diminished in people with MS.

And then we had a second project where we studied how taking vitamin D supplements at various doses, how that might affect gene expression of immune cells in people who have had a first attack suggestive of MS. And we did this as part of a sub study of the PrevANZ study, which was conducted at various sites across Australia and New Zealand. And in this study, we found that higher doses of vitamin D could indeed modulate or regulate the expression of various genes in the immune cells in the peripheral blood. And that these genes were involved in signalling between these immune cells but also the metabolism of these immune cells. And so, I think combining and taking the findings of both these studies together, it does seem that vitamin D is certainly able to regulate and modulate the immune system.

Jodi: So, does that mean that vitamin D can change the recipe or can it change the cake or both?

Wei: Yeah, I'd say the cake. So, it can modify how much of these genes are read or expressed and so you can sort of think about it as how many eggs or how much flour is put into the cake so to speak and that can obviously then lead to different types of cake.

Jodi: Going back a little bit to the basic sort of concept of vitamin D, which you mentioned at the start. What do we know about vitamin D in the immune system.

Wei: So, we know that previous studies which have looked at Vitamin D and the role in the immune system, they've been mainly done in the in vitro setting where you have your immune cells, and you sort of grow them together with different amounts of vitamin D. And then you see what happens to those cells and in the lab. Those studies had shown that vitamin D it does seem to modulate how these immune cells function and I'll say overall, it did look like it can help prevent too much inflammation. But interestingly as well, there's evidence to say that vitamin D can also help support these immune cells to fight off you know, certain infections and certain threats as well. So, it does have probably a few roles in terms of regulating the immune responses based on those previous studies that have been done as well.

Jodi: And how do we get vitamin D? So, I know that there's sort of a bit of sunshine, diet. If I was just, you know, Jodi Haartsen walking around, how do I make sure that I've got enough vitamin D? What do I need to do? With or without MS, get a good amount of vitamin D.

Wei: Yeah, so you're quite right, Jodi. So, there's certainly a few sources and ways that we can get vitamin D. And sunlight exposure on our skin is really one of the keyways to get vitamin D. As the sunlight, when it shines on our skin, it actually then leads to production of vitamin D within our skin.

Jodi: Right. So, it's all done in the skin there.

Wei: Yeah, that's right.

Jodi: And what about the gut? What about dietary sources of the vitamin D?

Wei: There are also certain foods which have a high amount of vitamin D, such as fatty fish like salmon or other foods such as shiitake mushrooms is another example. But the food sources are often not sufficient to get the amount of vitamin D that we should have and so the two main sources really would be the sunlight on the skin and also the vitamin D supplement. Which when we go to you know, the pharmacy, or even to the grocery stores these days, you know, they're quite freely available there.

Jodi: And in your experience, do lots of patients that you see with MS have low vitamin D levels? And in your research, did lots of people have low vitamin D levels?

Wei: So, we know that vitamin D deficiency is a risk factor for developing MS. And I'll say anecdotally in my experience, I have seen, you know, quite a number of people with MS who have low vitamin D levels, will be checked at the time of their diagnosis, for instance.

Jodi: So, if lots of people with MS do have low vitamin D, how often should they be getting it tested? What level should they be aiming for?

Wei: Yeah, so we would generally test someone's vitamin D level when they're first diagnosed with MS. And if we find that they are vitamin D deficient at that time, I would then suggest an approach to improve these levels. And usually, I would be suggesting vitamin D supplementation, for instance, something like 2000 units a day or two capsules of the off the shelf readily available vitamin D supplements a day with each capsule, usually having 1000 units in each capsule. The vitamin D level can then be checked again in a few months time to see if the approach that we're doing with the supplementation is adequate and in terms of an aim, I would really be aiming for the vitamin D level to be replete and sufficient, you. And so around a level of 75 nanomoles per litre or a bit higher than that is, I think, a reasonable aim to be at.

Jodi: And what about big doses? I know in some areas of medicine, the one that comes to mind is aspirin. You can take as much aspirin and it doesn't make your blood any thinner, so it doesn't have a negative effect. Do you think, based on your research and understanding, that more is better or more will make no difference?

Wei: Yeah, that's a good question. With one of our studies that was done as a sub study of the PrevANZ study, which tested a number of doses of vitamin D supplementation. We did find that higher doses could change and modulate the expression of more genes than at lower doses. However, as you know, with the main outcome of the PrevANZ study, which was to see if people who had a first attack suggestive was MS and so were at high risk of developing confirmed MS down the track. That study didn't show any benefit of even higher doses of vitamin D supplementation at preventing a further attack or a new MRI lesion at 48 weeks of follow up. So, it's not quite well proven that taking high doses of vitamin D necessarily will benefit people who have a preexisting diagnosis of MS. And it's interesting because we did certainly see those gene changes. But that didn't necessarily translate to benefit and certainly, you know, that's thought provoking and there's a number of things or hypotheses that we can propose for that.

I think based on the available evidence, I think it's certainly still reasonable to take some vitamin D supplementation and I'll probably say, you know, it's reasonable to take between probably a thousand to five thousand units a day. I think that will just ensure that we minimise the dips in vitamin D levels, when usually we would reach a trough otherwise in late winter, early spring. So that we try to keep the levels at a reasonable and hopefully sufficient and replete. And even though it's not conclusively proven that it will necessarily help MS disease activity, for instance, based on some of the observational epidemiologic type of data, you know, possible it might do something. It is certainly very safe at those doses I mentioned and it's certainly freely available and accessible as well. So, I think for those reasons, you know, it's not a bad idea just to take some.

Jodi: And is there any safety concerns about taking too much vitamin D?

Wei: Yeah, so at the doses I mentioned before, that's generally very safe for people with or without MS. There have been reports of toxic effects that can occur with vitamin D supplementation, particularly if people do take megadoses or doses much higher than say 10,000 units a day on a regular basis. People who have an underlying predisposition or medical issues which affect healthy metabolism can also be at risk for toxic effects due to vitamin D. But I think if we're not taking really big doses, that's generally very safe.

Jodi: I did want to go back to, sort of briefly mentioned sun, and I was thinking about the weather. Could I get enough vitamin D just from sunlight and do you think that we should have our vitamin D tested in the winter and in the summer?

Wei: So, I would say that sunlight exposure on the skin is certainly one of the key ways to get vitamin D in our bodies. And I think the best way to do that is to really try to aim to stay physically active, you know getting some outdoor activities because certainly staying physically active does have benefits of general health It also has benefits from the MS perspective as well, and that sun exposure will help with the vitamin D levels.

The other thing, of course, to bear in mind with sun exposure is that it's very important to be sun smart, particularly over summertime, because we obviously don't want to cause damage to the skin, because in the long term that will affect and increase the risk of skin cancers. And so, I'll be following that advice what the Australian Cancer Council is suggesting and recommending, that particularly when the UV index is three or more, that we should still be sun smart, using sunscreen, sun protection if we are out and about. I think given our lifestyles these days, where I think a lot of us are probably indoors for work nine to five. And again, because of the seasons where there can be less sun exposure during wintertime. And I think sometimes, or some of us anyway, might be going into the office in the dark and leaving the office in the dark. I think, again, taking a bit of vitamin D throughout the year will just again help to maintain those levels and prevent them getting very low, particularly in that late winter, early spring part of the year.

Jodi: And the second part was, should we get our levels tested in summer and winter? It used to be very much 10 years ago. We recommended to every patient, get them tested in summer, get them tested in winter just to see the difference. I interestingly found that some people had sun many days, worked outdoors and still had low vitamin D. And other people had high vitamin D and were inside all the time.

Wei: Yeah, so I don't think there's great evidence to say that we need to be checking vitamin D levels regularly. I think if we check it and we see that somebody is deficient or not sufficient in their level, we can then make some suggestions. And then if we check it, say, in a few months time, and maybe it'll be in a different season at that point, you know, we'll have a sense of whether our strategies are working. I don't think there's a particular need to say we need to be checking it regularly in summer or in winter.

Jodi: Hmm. So, get a strategy and If that's, test that it's working and then you can stay on course, is that your general thinking?

Wei: Yeah, that's right. I would say so.

Jodi: Yep. That sounds very sensible. One of the things that I certainly got asked a lot as a nurse was from parents about giving supplementation to their children and whether that was important. Most people seem to be very comfortable with taking supplements themselves, but really wanted to know how important it was in preventing MS if their children had supplements.

So, what's your response to that question?

Wei: Yeah, that's a good question. Okay. I might just take a step back first and just say that from an MS risk point of view, we know that MS is a complex disease and that there are both genetic as well as environmental factors that affect the risk of developing MS. And for a person who has MS and has children, we know that their children probably have a roughly 1 to 2 percent chance of developing MS. So, we can see from that number that it's certainly not absolute and the chance is still low. At the moment, we don't have any proven ways to prevent the development of MS, although we do know a number of risk factors that we do currently understand are modifiable or changeable. And so based on that, I would be recommending that for the children of people with MS, I think that we should be encouraging and promoting that they have a balanced diet. Participating in some outdoor activities in a fun, smart way, and being at a healthy weight range, for instance, just based on our understanding of those modifiable risk factors that lead to a higher risk of developing MS.

So really, I would say overall, you'd want to promote a good, healthy lifestyle. And I think in terms of your question of vitamin D supplements in kids of people who have MS, again, it's not proven. But I think given that we know that vitamin D deficiency is a risk factor for developing MS, I think it's probably a reasonable thing to think about whether the kid would be happy to take say 1,000 units a day of vitamin D just to again keep it up at a reasonable level and preventing it from being deficient. My understanding is that that's generally safe but it's probably not a bad idea as well to link in the children's GP and have a discussion around all these factors as well.

Jodi: I used to talk a lot about the actual child. Like, in the absence of clear knowledge, if you thought that it was going to make your child anxious to be talking about their risk of MS, if you thought that that was going to increase their anxiety or make them more anxious. Then think about that when you're making the decision, and the impact of what it has on how they're feeling, or their levels of anxiety, versus if a child's very relaxed and you can just give them a gummy and they don't care or they're not particularly anxious about things. So, I think that was sort of something that I always really added to the conversation that you need to, in the absence of solid science, which from what you're saying, we don't really have, then you can. Think about lots of other factors that around that child before you go ahead and do the gummies or the tablets or whatever It's nice to know that it's safe. But yes, I think that that's an important thing to think about how you approach that issue with your children and helping them.

Wei: Yeah, no, that's a very good point. And I think you know, certainly the risk is on the lower end I think promoting a healthy lifestyle is probably the main message.

Jodi: Yep, make sure you have some good sun and get outdoors. Yeah, that was great. Thank you.

Wei: Thanks, Jodi.

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