 Professor Schenkin I have my stopwatch on me so I promise I won't run over my allotted slot there is so much to say on vitamin D ladies and gentlemen that I could take all night. And you'd still be here by dawn and I want to finish so what I what I want to just do and in line with good housekeeping I would just like to declare my index conflicts of interest. I don't see any of them being particularly conflicts but because I'm talking about vitamin D particularly in the context context of COVID-19. I have done a little bit of work for the supplement company and also for the council for responsible nutrition and have given a couple of webinars and written them a dear piece for which a rarity was paid and I have donated that both to the university sorry hardship fund, and to the I've also done some webinars for the learning societies of nutrition society and physiological society and a guardian podcast for which there's no financial declaration and as you can see those are involved on this slide. Now what I want to really try to do is to take you through vitamin D from beginning to end and to really share with you what vitamin D is why it's important, where it sits and why there's been so much media debate about the importance of vitamin D both to immune function, but also in terms of COVID-19. And I'm going to share with you quite a bit of information and I will keep very careful on time and I can always flip over slides if I feel that I'm spent a little bit longer on explaining. And what I'd like to finish with is are some slides just on practical ways of ensuring vitamin D adequacy and to really bring you the most up to date information as it currently stands. So vitamin D so let's begin at the beginning. So vitamin vitamin which is of course used to have any on the end so vitamins are all vital amines and amines are of course a chemically composed group for which of course vitamin D is not a vital amine. It's actually a pro hormone. So it is a misnomer, you know, right from the outset. And it is the only nutrient in the broad spectrum of nutrients where our main source is not one of diet but actually UV exposure. And that UV exposure has to be at that wavelength as I list there to 90 to 315 nanometers in the United Kingdom and of course that would absolutely include Scotland in terms of the UV exposure. But just to bear in mind that on average, it is that we can make vitamin D between April and September. But the evidence coming out and particularly the work of Professor Anne Webb from University of Manchester suggests that the further the northern latitude. So certainly for areas of Glasgow and onwards, it would probably be nearer to May to late August, but would be that that window when you can make vitamin D and perhaps we can come back to that in the questions. And so what you will see in this slide is 70 hydro cholesterol. So that is a steroid that sits just under the skin. And then when UV light hits the skin, we then make what's called 25 OHD or 25 hydroxy vitamin D. And that is our clinical marker for vitamin D status. So what do I mean by that is, is if you are concerned about your vitamin D levels, you can go and get your 25 hydroxy vitamin D measured or 25 OHD measurement made, and that will tell you about your bodily stores of vitamin D. What makes vitamin D so unique is, of course, is that there is further conversion in the kidney to give us what's called 125 dihydroxy vitamin D, which is the active hormone of vitamin D. And that's very important. And I want to come back to that. This is the slide again shown in a little bit more depth. And so you can see here the 70 hydro cholesterol UV rays. And then the reason that I've highlighted this is obviously to just point out the importance of 25 and 125 and how they're different, but also to just point out to you at the top there that your body is very clever. You can never become vitamin D toxic through UV exposure. And what I mean by that is that after about 20 to 30 minutes of being in that UV light, you then won't make any more vitamin D for the day because what happens is, it goes to the package trial. So the body has adapted over, you know, of course, over such a long period of time, such that once you have your UV exposure for the day, that's it, you won't make any more. And it's some failsafe mechanism of toxicity. So you can never, ever become vitamin D toxic through UV exposure. And you only need 20 to 30 minutes of being in that sunlight to make some vitamin D. And if you wear clothing, or you're behind a screen, or you put on sun cream or ladies put on face moisturiser, that will block out quite a lot of the vitamin D manufacture. And perhaps we can, or I'll certainly come back to that. So a useful take home message is make no vitamin D. So it's when your shadow is shorter than your height. So it will start to now turn in April. But when you go out and if it's a sunny day, have a look at your height and in on a sunny day in the winter, it will be double your height. And then we know it's to do with what's called the zenith angle of the sun. The sun wavelength is such that the sun of course drops in the winter. And that's what makes our shadows much longer. And this isn't me making this up. This was a real publication by Dr. Holloway in the Lancet many years ago. And just purporting to that fact of the importance of your shadow in terms of UV exposure. Now I can't possibly talk about vitamin D without just saying just a few words about this extraordinary lady, Dame Harriet Chick, who of course was one of the first key scientists that showed the importance of both sunlight and cod liver oil, and preventing rickets in children and of course I show a slide here of children with rickets. The little child on the left has not knees and the other child has bandy legs and that is a softening of the bones and you can again see that in the bones slide there, there's a softening of the bones because there is insufficient both vitamin D but also calcium, so it makes the bones very soft. And of course cod liver oil was tremendously successful in cutting out rickets. It's also very important for osteoporosis prevention. So again here I show a slide of somebody with healthy vertebrae, somebody with osteoporotic bone and then if I just highlighted that in the yellow and blow it up for you, you can see this is osteoporotic bone and then blown up even further, you can see the tremendous trabecular, the bone, trabecular bone or cortical bone, which are our two types of bone that we have in the body, and this tremendous disconnectivity such the bone is very becomes very worn away and liable to fracture upon impact and we know that vitamin D is very important in preventing osteoporosis. We know that vitamin D deficiency is a huge problem, not just in this country but across the world the WHO estimate that about 2 billion people living in low to middle income countries have vitamin D deficiency and nice predict that we spend probably in the region of 100 million pounds a year on vitamin D supplementation. Now, if you remember back I said about the cut off or I said about that you can measure in your body, this 25 OHD 25 hydroxy vitamin D. And then this is a slide that shows you the difference, the different countries who have come up with their guidelines for vitamin D, and where they've set the cut point for vitamin D deficiency or vitamin D adequacy. And as Professor Shankin very kindly said I do indeed sit on our scientific advisory committee on nutrition. So it's similar to sage but it's a, it's a committee that deals with nutritional issues rather than a group on emergencies. And we set our cut point at 25 nanomoles per liter so what we say is that we don't want anybody to be below 25 nanomoles per liter for their 25 OHG status for their vitamin D status. The American as shown in the orange set deficiency at 30. And then what they do in their government recommendations is on looking optimal health so they are trying to achieve 15 nanomoles per liter and FSA the European Food Aid Safety Agency also set that cut point at 15 nanomoles per liter. And then what you will also see on here in the red is the endocrine society and I showed that not because it is a government recommendation, but it is an organization that believes that we should be much much higher at 75 nanomoles per liter for optimal health. And I'd like to come back to that because there has been a great deal of controversy as to whether we really need to be at that higher level. What I show in this slide is concomitant with those vitamin D levels. These are the recommendations that have been now been published across the world and I show there in the purple second, the American DRI the green and the orange there. The North and New Zealand. The Nordic countries really have all set their recommendations for vitamin D somewhere between 10 micrograms and then slightly higher up to 25 micrograms and we can come back to that. Perhaps in the questions of the controversy and the differences between different countries. until 2016, we had no recommendation for vitamin D and the reason for that is was because it was considered that we made enough during this summer, challenged by a number of different scientists, indeed including myself, I wasn't on second at that time, I didn't come on to second until 2010 and we really challenged the government and said that we felt that their thinking was scientifically in wrong and we finally in 2010 we got the green light to run a full risk assessment for vitamin D so what that means is we then set about reviewing all the evidence to see if we should make a change and on the 23rd of July 2016 that was published by Public Health England and the new recommendation is 10 micrograms per day or 400 international units, one microgram equals 40 international units and that was a big change for the United Kingdom to go from 0 up to 10 and as I highlight here in the purple this new recommendation represents a very significant challenge of course to the United Kingdom because we would achieve no more in in our diet than about 3.5 micrograms which is equivalent to about 140 international units per day because there are so few foods that contain vitamin D. Now the reason that there's been so much in the media about vitamin D and the immune function is because of the discovery of the vitamin D receptors or VDRs as they are known and also vitamin D metabolic enzymes that have been shown to be present in immune cells and that very much provides the scientific rationale for the importance of vitamin D in maintaining immune homeostasis and of course in preventing the development of autoimmune processes and I show on this slide and I just highlight here for you in the green that vitamin D receptor of how important it is in terms of translating on really getting in and working in those immune cells. This is a beautiful review, it's open access and for any of you who are interested in I would encourage you read it's written by really one of the most world leaders in vitamin D and immune function Professor Martin Hewison from the University of Birmingham and indeed this is the nutrition society's most highly cited paper on vitamin D and he includes some very important references that I just share with you here they're very busy slides and I don't have time to go through them in great depth but I just highlight for you here this very important enzyme SIC 27B1 which is of course very important in the mechanism of vitamin D and its manufacture and how important that enzyme is in its workings in all of those different cells that I list there but also in the non classical functions of vitamin D. This is another very busy slide but I just want to just highlight to you and I'm just putting them all up in in red all of those these different functions of immune homeostasis require vitamin D activity and that vitamin D receptor so this is really right down at the cellular level showing you how important the vitamin D receptor is and how important that active hormone of vitamin D 125 is to immune function. Now when we then put that into the context what we see is that it's been hypothesized that there is an association between seasonal upper respiratory tract infections and low vitamin D status because nine times out of ten both of those occur in the winter but and I think this has been borne out so much during the COVID pandemic that actually our activities when we're indoors that there's a much greater proximity to individuals there's much more likely to be interpersonal transmission and it's not that simple to say yes in the winter I'm vitamin D deficient that must be why I get a cold that said the mechanisms are most certainly there and I do believe that there are many many people hopefully less now and and of course the COVID pandemic has been a very tragic time for all sorts of reasons but it has put vitamin D in the spotlight and I hope it's made people appreciate the importance of that nutrient and the importance of taking a vitamin D supplement during those winter months when you will achieve very little or no virtually no vitamin D manufacture from UV exposure. Now what we see here is this was a very good publication it captured all the media it was published in the British Medical Journal it was a systematic review of meta-analysis so what that means is that pulling together all the different randomized control trials all the observational studies looking at vitamin D and immune function but there whilst it got into a very good journal and it's achieved a lot in the media it's very important to point out that that original meta-analysis was very much focused on two trials one in Mongolia and one in Afghanistan and we have to be very careful to extrapolate data in developing countries when the characteristics are going to be very different to that in developed countries. And indeed there was a lot of correspondence and a lot of debate by statisticians who were very critical of that paper. What has subsequently now this will be out in the last it should be next week I did speak with Professor Martinou last week it's now been accepted so this is an updated meta-analysis and what's very important with this updated meta-analysis is that the reliance on the those two large developing country trials has now gone it's a much more balanced meta-analysis and what's very interesting is whilst the overall effect size is likely to be overestimated due to publication bias what's very interesting is that the protection from vitamin D against acute respiratory tract infections was most impressive in doses that were between 400 and a thousand international units given on a daily basis and the large bolus doses which of course have been rife in all the media to say that everybody should be taking huge doses 10,000 50,000 international units of vitamin D per day those studies that were done looking at those sorts of doses actually didn't work but the results were best and aligned themselves very well indeed to the second recommendations of 400 international units per day and again perhaps we can come back to that in the questions now when we look at that this was another meta-analysis that was carried out it was different to the Martinou group because it only included healthy individuals and indeed could not find any protective effect of vitamin D against acute respiratory tract infections this was another trial that came out by the New Zealand group very large trial used a very high dose of vitamin D and as you can see there what the study found the bottom line and there's an awful lot of detail there and and of course I've sent through the slides and I'm very happy for you to have all of them so you for those of you who are most interested in the depths and the detail you can look at that in your own time but the bottom line ladies and gentlemen was that it had no effect that large dose given had no effect the Professor Martinou's group have published just about six months ago now a new trial this was carried out in Mongolia again you can see large doses 14 000 international units of vitamin D given weekly this was published in the New England Journal of Medicine and again highlighted what the study found there was no difference in acute respiratory tract infections or tuberculosis infection or disease between the vitamin D and placebo groups given those high doses now in the trial that we uh got some funding for from the government to look at the effect of diet on vitamin D status to really answer that question that do you if what that which you make in the summer does it last you during the winter and I just show this slide because what's very important so this was you can see on the bottom axis so we measured vitamin D every season for one year the red and the blue bars indicate the pre and post-corkasian women and you can see that they had higher levels during the summer and then this dropped down during the winter and we also had in the orange and the green bars south asian older and younger women and you can see if you run past your eyes across they were below 25 nanomoles per litre for almost the entirety of the year there has been a great deal of speculation because covid has been so detrimental to ethnic groups that that again is linked to vitamin D i we haven't really explored and got proper answers to that yet but it is undoubtedly the case that ethnic minority groups are very vitamin D deficient and they are a group that we really need to focus our attention on and we've done a lot of work on the UK Biobank so that is the UK Biobank includes across the UK 500 000 individuals and we've been very privileged enough to win a grant to be able to look at vitamin D levels in those 500 000 but particularly in south asians and this is the largest study that we can find across the world on looking at vitamin D status in south asians and you can see in this graph i just draw the line in blue where 25 nanomoles per litre sits which is of course our recommendation of the united kingdom for deficiency and you can see for yourself vitamin D deficiency is almost universal in UK south asians with over half from 55 percent of them below 25 nanomoles per litre and that's not to forget that 10 percent of the samples were below the detection limit of 10 nanomoles per litre so there are real deficiency issues and in a second publication if you just look at that box that i've shown you there they're intake varied of vitamin D between i'm in the indian group one microgram per day in the pakistani group 1.5 micrograms per day and in the bangladeshi population three micrograms per day so they are really very low indeed now it has been purported and this is a very important study within the realms of vitamin D deficiency and acute respiratory tract infections because it was carried out in african american women this is the only trial that we have on vitamin D supplementation in a prevention of acute respiratory tract infections and what the professor john alloy did with his group was that they gave a dose of vitamin D to keep the vitamin D group above 75 nanomoles per litre which was really to answer the endocrine society that have been very vocal in the media and indeed were very vocal when we published the second report and indeed in the publications that i've done and i'm going to share with you on covid in just a moment have been very vocal to say that we are completely wrong and they people everybody should be at 75 nanomoles per litre so this randomized control trial was carried out and achieving 75 nanomoles per litre or above in black african american women and then the placebo group who were much lower than that there was no difference in the occurrence of acute respiratory tract infections between the two groups now that shares with you the evidence of vitamin D and acute respiratory tract infections now how does it link potentially to covid and the two mechanisms are as follows ace two or angiotensin converting enzyme this is an enzyme that attaches itself to the outer surfaces or the cell membranes of cells in many different organs ace two also lowers blood pressure by catalyzing the hydrolysis of angiotensin two we know that ace two is a key player in the raz system the renin angiotensin system and its loss of function can have devastating effects and what we also know and that is absolutely right from a mechanistic point of view vitamin d is a negative regulator of razz and that normalization of vitamin d levels can lower razz activity um you know through um through what we would call a transcriptional suppression of renin expression i'm sorry if that sounds a little technical but i'd just like to show you the science just so that you know mechanistically there is certainly potentially a link but what we then have to do is to look at the science to see if the science holds up to that now this study ladies and gentlemen i remember it very well because not only do i sit on the satin but i was asked to join a working group for the cabinet office and i did a lot of work for them in the early part of covid um interpreting data for them and sharing with them all the mechanisms and this study came out it was published on what's called a pre-print server so you can put papers up onto a pre-print server before they all then go out to peer review and it's something that is done a lot there is a caveat to say that it's not peer reviewed this paper was put up um i received it from the cabinet office i sent it to the senior statistician at sorry he checked all the stats with me and it looked a very strong paper you can see in the bold box how many times it's bound down loaded over a hundred thousand times and i'm sorry to say um ladies and gentlemen by then in last summer shared an afternoon with the editor-in-chief of the british journal of nutrition this letter was published to say that those authors in this study did not exist and the whole of the study was made up and somebody had planted it in the media to get it across all the newspapers the times the telegraph the BBC news it was everywhere but that study and this is the letter and again you've got the reference you can easily pull it up this letter was written by indonesian doctors who are based you know in the location where this study was purported to have done and the whole thing was made up and planted in the media so i think that just shows you how cautious that we have to be and indeed that pre-print server you can see there the email address um rules have now been changed that no gmail addresses now be used it has to be with an educational institution and they let this one slip through to the damage i think of people seeing that high vitamin d levels were protected against covid and it simply isn't the case it was all made up so what i did was very early on um i pulled together some key names in in vitamin d um and who all have different views and it was like trying to herd cats to get them all to a grieve to to to some wording but we really wanted to get science and sense out there and so we published in the british medical journal nutrition health nutrition prevention and health a consensus paper of the evidence that is open access and can easily be downloaded and as a group we are now working on a second publication which we aim to get out again in may one year on to say that which we recommended last time has it changed any difference and i'm going to come back to the summary conclusions that we had but if you look at the trials that have been done on vitamin d and and covid this was a very interesting study this was a swiss study and again that's a very busy slide and i don't have time to go through it in great detail but this trial showed lower vitamin d levels in those um uh that were aged over 70 years who'd had a positive covid test but it's very important to bear in mind that vitamin d is a negative acute phase reactor so if somebody is unwell it will the levels will fall and that is something that many people especially those writing new media don't always appreciate with vitamin d this was a trial now i think the evidence for of course we need randomized controlled trials this is the most promising study this is a pilot study we're now waiting for the main study to be published and it was a period out in spain where they allocated hospital patients who had covid with a very high dose of vitamin d now what i would say it's a very very high dose of vitamin d what was um rather ashamed although that they were randomized the groups who were who had covid and who didn't have covid were not exactly matched and indeed those who didn't have covid had a different blood pressure level and and some other health outcomes that were slightly different so whilst it demonstrated a significantly reduced need for icu treatment of patients requiring hospitalization with covid 19 it in no way is proven cause and effect because there were differences in the groups very interestingly this study was a pilot study a larger trial was published and indeed was put up last week onto the pre-print server but it was taken down after a lot of complaints to say that the data did not stand up to scrutiny so further analysis is being done on that and so we watch this space for those of you who are particularly interested in in this topic i would encourage you to look at these reviews so we as a sac and panel published um a two reports so one in june and one in december looking at the link between vitamin d and acute respiratory tract infections and we felt in june that there was not enough evidence to make a recommendation for vitamin d and prevention of acute respiratory tract infections but in december with a larger number of trials and a new meta analysis that was not dependent on developing countries we were happy to change that recommendation so the vitamin d um as a second panel now says that it may be important in in preventing acute respiratory tract infections we also as a second panel and indeed i was asked to review four nice their two reports on vitamin d for covid treatment and prevention both in june and then again in december and the evidence we didn't feel stood up to scrutiny and that we could not make any recommendation for vitamin d either as a preventative or as a treatment strategy for covid 19 and those reports are all downloadable for free from the nice and the second websites and make for you know a very extensive read and they were announced the new reports that we did were announced by the secretary of state on the 18th of december and we are continuing to keep a watching brief on any further information now when you're all thinking about and and i'm mr chairman i've got my stopwatch on me so i'm keeping a very careful eye on on where i am and i estimate that i think i've got about another 10 minutes or so is that right professor shankin is that what you predict yes our 15 15 lovely thank you very much so you're all thinking okay so vitamin d is important and as professor shankin said in in his introduction we should really try to achieve a good nutrition through a balanced diet and as a registered public health nutritionist myself i don't agree with poking pills i think there are exceptions in different places for example folate for women who are trying to conceive would be a good example but also for vitamin d that during the winter our recommendation as a second panel in 2016 was that everybody should take a vitamin d supplement during the winter months to just keep those levels stopping from dropping below 25 nanomals per liter and 10 micrograms will achieve that for 97.5 percent of the population that then lends itself to the question okay if i'm going to take vitamin d should i take d2 which is the plant source or d3 which is the animal source and this was something that i'd followed in the literature quite a lot and all the literature up until uh 2000 about 2009 2010 most of the literature said that it didn't matter which form of vitamin d you used d or d3 you would see the same change in vitamin d status and so i wrote a grant again to the government this time not to the food standards agency but to the biological and biotechnology sciences research council bbsrc to really address the difference between d2 and d3 and so i submitted my grant and as luck would have it this paper got published in the american journal of clinical nutrition by professor mike collick who's a huge name in vitamin d he's done so much in the vitamin d field indeed wrote the enterprise society guidelines to say that we should be at 75 nanomals per liter and i've followed much of his work as a as a doctorate student and he's won many awards for it and he published with his team a study that was exactly what we had written in our grant application which was to look at d2 versus d3 in an orange juice and what he said in that publication was that there was no difference and that giving the animal or the plant form made no difference to your vitamin d status when i saw that i was thinking oh well let's hope the reviewers of the grant don't see it and i wrote a letter um because i thought that they probably would and so i wrote a letter with two very big names in vitamin d professor rinald v from canada and professor robert heaney um your seat ladies and gentlemen i stopped short of saying what a dog's breakfast of a study that was um i was a little bit polite and said fundamentally flawed study methodology because the reason that i said that was because in his trial he had an n of 12 in each group and in the grant application that we had just written i had done a lot of statistical analysis with our senior statistician and we had calculated you needed a sample size of no less than 65 so he came back um with an equally rebutted statement to say and you can see there they're in i don't know if i highlight yes i do therefore on the basis of all these analysis it can be concluded with a high degree of certainty that d2 is equally as effective as d3 at raising and maintaining vitamin d levels the reviewers of the grant did indeed see it and in fact two of them wrote that our grant application was now redundant because of the new holic study that showed conclusively that d2 and d3 are the same i'm very pleased to say ladies and gentlemen that the grant panel were i think so impressed that we've got our letter out in the american journal of clinical nutrition so quickly that they still gave us the money because they felt that it was going to be such an important question for the food industry and so here we are these are the results um a few years on so i show you here in the orange bar is d3 in the green bars is d2 and in the blue is placebo we had a juice and a biscuit so we changed the design at the request of the panel because of the holic study they said let's not just do juice let's do a solid food as well so we did a juice and a biscuit and you can see for yourselves that by that graph that d3 was 50 percent better than d2 in raising and maintaining vitamin d levels and in no way could you say that they were equally effective and i honestly believe ladies and gentlemen that were it not for that uk funding that we would still be saying that there was no difference and this has been one of the most influential studies in vitamin d and indeed was the bbsrc put it in their strategic document to say it was a very example of we're doing research that's of relevant to the food industry and we now have and i don't have a slide because it literally only went up yesterday but and i was waiting to make sure that it's got up safely but we've now done some very clever gene expression work of the difference between d2 and d3 and what our results seem to suggest is that actually if you give d2 you may actually be making things worse and perhaps i can come back to that in the questions i think we probably need more data but the bottom line is that if you can take a d3 supplement not a d2 one and so just to to finish off just with a couple of slides on the practical applications or the practical ways of getting your vitamin d levels up eggs sardines 45 cereals some 45 milks not many in the united kingdom but certainly the dairy free alternatives do have vitamin d added those are of course all d3 sources mushrooms are a source of d2 but um the bottom mushrooms as you see here are grown in the dark so if i have any mushroom levels in the audience then a very useful tip is to put your mushrooms when you're cooking them April to September or perhaps May to to end of August given that you are of course in in Glasgow to put if it's a sunny day put your mushrooms on the windowsill and you will increase their vitamin d2 content in the paper that we wrote in the British medical journal there is a beautiful summary of safe sunlight exposure to boost vitamin d status and that was written by the second author of the paper Dr Anne Webb who is the professor of atmospheric um environment at the University of Manchester and indeed and she did her PhD with Professor Mike Collins so it's a it's a small field but she really knows her stuff and the bottom line is that you need about 20 to 30 minutes of sunlight exposure without sun cream on your face the backs of your hands your neck your arms will provide you with your vitamin d levels for the day and to try to do that on a daily basis so you keep your levels up we've tried to um that i do have a guardian podcast that i've done on vitamin d and that captures everything that i've said here and um what we also would say is of course very early in lockdown public health England published its new advice on vitamin d which is of course 10 micrograms per day and for that to be maintained during those winter months um you know throughout time we can maybe come back to whether you need to take it during the summer months and of course what was lovely to see was the government have also provided free vitamin d pills for two and a half million vulnerable individuals certainly in England and i know that the Scottish government have done the same in Scotland so to draw to a close to my talk i would just like to finish just with some final statements vitamin d is absolutely essential for bone and muscle health that was born out in the american recommendation in the uk recommendation we do not have enough evidence i think certainly for covid and whilst we would like some more unacute respiratory and upper respiratory check infections i think we can now say that in some individuals that vitamin d may be beneficial many people have low vitamin d levels especially if in the winter or indeed if they are confined indoors and of course during lockdown that was a big issue during the summer because of course summer and sunshine is the main source of vitamin d for most people and those government recommendations of 400 international units or 10 micrograms are particularly important and especially so if an individual is not getting out in that sunlight and of course what's also important to bear in mind is vitamin d is a fat soluble vitamin and so that means it's stored in the body and of course there is an issue of toxicity with vitamin d and i'm very pleased to say that the uk american and european panels all independently of one another agreed on the upper limit which is 4 000 international units per day or 100 micrograms so what that means is that an individual can safely take 10 times the r and i i.e 10 times 400 international units per day and not have to be concerned about vitamin d toxicity i think what i would say is to question why you're needing to take that much if you do but you can certainly do it safely but no more than that and there have been you know a huge amount in the in the literature to say 10 000 international units 50 000 international units per day and that is just dangerous and so please please be careful what you read in the media and those reports second and nice are you know all available you know on the website i leave you with just names i won't read them all out in the interest of time but we have a fantastic group at sorry you know we all work together on vitamin d and here are some of the names and ladies and gentlemen thank you very much indeed for your attention we have a lot of questions so at the last count there's 23 questions in the box so i don't think we're going to get through them all but we'll try and link a few of them together i think it's through just to start if we can maybe just to nail once and for all if we can this question of vitamin d supplement the supplementation and acute respiratory infections there seems to be some uncertainty as still about first of all one question saying saturday's bmg editorial said vitamin d supplementation of 10 to 25 micrograms a day has a modus modus protective effect against acute respiratory infections but your final conclusion slide if i understand it didn't say that could you please comment and with a similar question from another gentleman called phil saying disappointing there appears to be no causal link established between prophylactic use of vitamin d especially given the possible link in bmg communities and their levels of vitamin d if a good enough study were done could this link actually be be proven once and for all so what's the story thank you very much indeed so i would say on the basis now so that editorial which i did see i think is it we are now moving to and indeed seconds final conclusion was from the new work that we have have done is that vitamin d may have a modest effect on preventing acute respiratory tract infections i think the problem that we have is that we don't have enough trials in developed countries we do have more in developing we don't have enough in in affluent societies but i would say that certainly of those trials that are there that 10 to 25 micrograms which is what the martinu study showed does potentially have an effect on acute respiratory tract infections i think certainly for bain groups we just don't have the trial the only trial that we have is of course in that american african african american women where actually getting them to 75 nanomultiply to didn't prevent acute respiratory tract infections but undoubtedly you know that is where we need to focus some more attention and to encourage in particular all population groups to take their vitamin d during the winter when they're going to be at risk of being low and particularly for those bain group because they are so vitamin d deficient and moving on there there are a number of questions about the about taking vitamin d supplements of course is there a difference between vitamin d from sunlight and from taking a supplement or are they both equally effective yes they are i mean they will raise your vitamin d levels most most certainly i think where they're different is that your uv exposure source will mean that you cannot in any way become vitamin d toxic but your dietary source has the potential to but you know you'd have to be at very high levels so yes so if you are able to get out in the sunlight with your about 10% of your body exposure your face your your neck the backs of your hands your arms if you're able to do that during the spring and the summer then it may be that you don't need to take your vitamin d supplement because you're getting your uv from sunlight the recommendation that we made from sagan was because people are deficient during that if we look at the national surveys there are still a number of people who are vitamin d deficient during spring and summer so that's why we recommend it all year round but i would say to all of you if you're able to get out and probably it in in northern areas you know of in scotland it's probably more like may to end of august or more may to the beginning of september if you're able to get out you wouldn't need to take that vitamin d supplement but if you feel that you when you go out you're covered up an old and aging skin will still make vitamin d as efficiently actually as a younger skin but we just tend to go out more covered up so if you are concerned it won't do any harm to you to take that vitamin d supplement okay yes and and carrying on just with the supplement theme and is there any difference between taking vitamin d supplement weekly or daily i think you actually covered that but just a quick response that's a i'm glad that's come up again i would say that to take it daily the large bolus doses they don't seem to work either for prevention of acute respiratory tract infections taking it daily 400 to 1000 international units per day is what the meta analysis showed so i would encourage you not to take it weekly but to take it on a daily basis yes i would encourage that okay and quite a number of questions about sunlight of course again just carrying on to sunlight theme um it will a couple of weeks of winter sun in spain in the winter be enough to boost vitamin d levels presumably boost them adequately to to cover you for the rest of the winter it wouldn't boost you adequately it would boost you a little bit the half life so what that means is how long the vitamin d stays in the body is about 28 days so you would achieve a boost to your vitamin d levels but then it would still drop okay and and the other side of that question can you make vitamin d on a cloudy day yes you can some uv rays will still filter through the more pollution that there is that will certainly inhibit the uv rays but on a cloudy day you will still make a little bit of vitamin d but obviously not as much as as if the the sun is is stronger no but i guess given the fact we have a lot more cloudy days and sunny days here and if we're out in a cloudy day for an hour does that compensate for 20 minutes in the sun oh that's a very good question and i would say um professor shankin we don't have really enough data to be that not surprised no it's so complex and not only is it dependent on the cloud cover but it's on an individual skin you know the amount of melatonin they have that how dark are their skin is there's so much variability to it and and also in terms of an individual i i didn't say that in my talk but somebody with a higher bmi will have lower vitamin d levels so again you know the body composition is is very important so you know somebody who is you know overweight or obese that is not good for their vitamin d health and there are a couple of questions ready to do with seasonal affective disorders and this one uh maybe not specifics in fitzman b but i saw interior lighting systems claim to combat seasonal affective disorders do you have much experience with this and do artificial lighting products such as this actually have any benefit and it's a very good good question really relating to sunlight and seasonal affected disorders it does and sad of course you know i think there has been now i'm straying into territory that i don't know anywhere near as much as i do the musculoskeletal health but of the evidence that i've seen there certainly seems to be an association but there haven't been the round the strong randomized control trials and of course you know we have to we have to apply the same rules in nutritional science as we do in every other science and that is you know is the science robust enough and it is the randomized control trials that give us that robust data and they just simply haven't been the randomized control trials in that disorder but they certainly have been observations that people with sad that do have lower vitamin d levels and i would certainly encourage to take it i think the jury is still out on on the light thank you yes and and another question which is perhaps relates a bit more to scotland just whether reflection on snow can actually improve the um in winter whether this is actually beneficial in terms of vitamin d production you know that's an extremely good question and i'm not sure that there's really been much science behind it but what i would be guided by is the fact that you know your skin will burn and so there would be because obviously there is a very strong correlation between the extent of tanning and the increase in vitamin d status that you have so that's a very good question and i think i would need to look to see of the evidence of that i don't think many people have done a study on it but my guess is is that it might be quite helpful but i maybe i can take that and what i would say professor shrinkin if there are any questions that we don't get through you know people are very welcome to email me and i'll do my very best to to answer that i can easily be found at the university of sorry and certainly the person who's asked that snow question i can certainly well the person who would know would be professor ann wedd um what she doesn't know about uv light and no one knows it's not worth knowing so that would be certainly a question i could ask her it's certainly interesting when you see some of the postcards of people skiing and often stripped of the waist or even more just do it take advantage of the good weather you sometimes get okay um question here with prisha for three years ago in march and we're on to blood tests um my gp referred me to a consultant who referred who requested i this is march requested i have a blood test it proved negative for the original concern consultant found my vitamin d count was low recommended i take a vitamin daily was she correct could the result have been different if the test had been done in august and am i right to take the vitamin all year round i'm now 70 that's a very good interesting question there it would certainly probably have been different if you'd taken it in august um because you would have march is when you've come to the end you know you're really at your lowest level for vitamin d but she was absolutely right a to measure it and be to recommend a vitamin d supplement you probably don't need to take it during those summer months but if you're comfortable taking it they're not expensive of course and if you're into the process it's certainly not going to do you any harm to have that as well as some UV light yeah right thank you some interesting questions here about vitamin d supplements and interactions with other medicines should people taking ACE inhibitors for hypertension take vitamin d supplements now that's a very interesting one certainly for statins there's been quite a lot written um with respect to the conflicting mechanisms and that statin users are very likely to require you know a higher vitamin d intake for ACE inhibitors do you know what i'm really not sure and i think that that would be it's a very good question and rather than give an answer that i'm not 100 certain on i think i would need to to just take that away my guess mechanistically potentially yes yeah i mean there's quite a quite a number of other questions about about interactions with other drugs which perhaps people should take up separately with you because i think they they're a bit too personal and one interesting one which i would also have wanted to know the answer to thank you for the informative talk is there a similar observation on the intake of multi vitamins on covid or have you only been looking at vitamin d oh well now i've only been looking at vitamin d but we as a second panel we've been looking at other nutrients and very similar to vitamin d i think there's no conclusive evidence yet and let's hope you know that there are more studies coming out certainly zinc and selenium have been suggested to be important but those are only observational trials those are not good randomized controlled trials so i would say at the moment just trying to consume a really healthy diet is you know is is the best approach okay um one or two questions back to supplements again and does it matter if it's in d is taken through cod liver oil or through tablets um no it doesn't cod liver oil is a good source the only thing i would say with cod liver oil of course is that it's very high in vitamin a and you know there were some studies some time ago now but looked at high levels high intakes of vitamin a and showed a link with an increase in fracture risk so that would be the only caveat that actually if you were to take a fish oil and a vitamin d supplement you because of course the cod liver oil is extracted from the liver of the cod so it's very high in vitamin a and so that might not necessarily be something that you would want to be doing particularly if you you know you consume vitamin a high consuming a high consuming diet so maybe switch to fish oils and to a vitamin d supplement but yes certainly cod liver oil has been shown to be you know very beneficial in terms of raising vitamin d levels okay and there's there's a question from uh forester coburn who is the uh professor uh former professor of pediatrics and in child health in Glasgow uh pointing out there's a lot of history in Glasgow saying that uh christina go presents a Scottish health services nutrition survey of immigrant children in Glasgow in 1974 to 76 and then various other studies just saying it's a very strong Scottish problem in particular I think given what you've said earlier on in relation to um the the problems of vitamin d deficiency especially in Scotland oh thank you very much for that comment and and that is absolutely you know the case that you know those early studies were were very important and as you say were were based on on children in in in your beautiful city okay um getting back to testing is there a simple test you can take to establish vitamin d status or do you have to get a blood test and sent off to a specialist laboratory I would encourage you all there are kits that are sold there are fingerprint testings that are sold I would be cautious with them I think it is much better um a laboratory that is through you know a GP centre will be measuring vitamin d um in with the most highly sophisticated methodologies so it's likely to be what's called LCMS liquid chromatography mass spectrometry which is the best measurement in the world and I would encourage you to just be cautious of these home kits that you can buy they really are not as validated as as what they would purport them to be okay um getting back to one or two slightly more general questions perhaps why are the recommended levels so different between different countries that's a very good question and I can answer it in in a very simple way it's because the different countries have different criteria for setting their recommendations so in the united kingdom we are our recommendations are for preventing deficiency whereas for example america its recommendations for nutrients are for optimizing health and that is why you you will see differences in different levels right okay can I ask you questions you just a personal which still surprised me we used to have fortification of margarine with vitamin d for about 70 odd years it started immediately after the war we fortified margarine with vitamin d and then just a few years ago it was decided to stop fortification what was given where we are now was that a good decision and you're absolutely right and I I have tried to look into that alan as to why we stopped that when yellow facts were introduced you're absolutely right we put vitamin d in there I the only conclusion that I've been able to come to is that the vitamin d that was put in was so such a small amount and if you look at the 1954 british birth cohort on the work that was undertaken by professor elena hippanon where she looked at margarine and non margarine consumers and could find no difference in their vitamin d levels so I think one of the reasons that it was taken out was because the levels were so small it virtually made no difference but we certainly need to look at that going forward because as I've shared with you you know we spend a huge amount of money on vitamin d supplements if we could get more vitamin d fortified foods that could be very beneficial you know to the population at large thank you okay why don't you well the more specific questions is there any connection between ms and vitamin d deficiency there has been and again this isn't a field that I know terribly well but certainly if you look at the geographical showings of ms you know across the scale it does occur in populations where low vitamin d status is prominent so certainly epidemiologically it does stand up but the randomized control trials as they currently stand you know have not shown you know a proven causal effect but I think there's still an awful lot more research that we need to do on that and I I would say I'm not the best person placed to answer that because I've not studied that condition in in a great amount you know of depth or detail and and another one just the given the fact that you're also a national advisor in the national osteoporosis society and you focused really only on vitamin d tonight but are you concerned about calcium intake especially given the trend towards veganism that's a very good question the I would say no I'm not too concerned when you look at our calcium intakes and the veganism of course is you know we have to be careful with veganism in terms of you know are all the different aspects covered and I would say you can still get a calcium rich diet on of the calcium rich you know nutrient supply on a vegan diet and if you look at the plant based milks there has been a great effort now to fortify them with calcium they the calcium is not naturally there as it is in cow's milk it's added in but soya milk for example you know is equally bi-available we haven't done those studies but the Omaha group in the USA have done all those comparative studies and they show that calcium absorption is as good from plant based milks as what it is as from cow's milk and of course we still have um Professor Schenkin of course what we still have is calcium in flour and that was brought in you know in 1941 during the Second World War and that still stays and five years ago as the second panel we were asked by the food industry to relook at that that calcium in flour do we still need to do that by government law and in younger populations flour-based products provide about 20 to 30 percent of our calcium supply so I would say I'm not so concerned actually I think as a nation if you look at the levels we we are achieving a fairly a decent amount of calcium okay and I think one final question maybe taking back to this whole question of the media and what was the object of the Indonesian doctors in planting such a biased report or on the benefits of vitamin D supplements and what what is fraud in science is so important and trying trying to understand how it happens why it happens and how to detect it that's a very good question I think I don't think it was Indonesian doctors who put it there that those authors don't exist in any of those hospitals I think and I will I can honestly say when we published our BMJ paper our consensus paper you would not believe the number of abusive emails that I got hundreds of from people who have very firm views about vitamin D who are making a lot of money from vitamin D so I truly believe that actually it was planted not by doctors but it was planted there to put vitamin D in the spotlight from a profit point of view okay okay I think that's a nice controversial way to to finish so you've answered an enormous number of questions given us a terrific talk and I'd I'd now like to hand over to Professor Pat Monaghan who will give the voice of thanks thank you very much Alan Susan it falls to me now to both thank you for your talk and to present you with the Graham Medal which you can see a picture behind me here don't worry it's not that size and it will come to you in the post but I'll come to that in a moment I first on behalf of the society and its members and everybody who's been listening this evening I'd like to really thank you for what has been an extremely informative uh up to date an honest talk about vitamin D a science-based and evidence-based talk which is very important and it's also very important that the talk was coming from someone with a very high level of expertise in the subject area you're emphasized in your talk uh there need to be very wary of fake science um to be very wary of even scientific information which has not yet been subjected to scrutiny and that scrutiny the public can't do that it has to come from other scientists and that's a problem for the public where do they get reliable information from and and people need to be very you emphasize the number of times of that very important issue of be careful where you get your information from um so thank you very much for all of that also thank you for your tips about what to do with your mushrooms I think we'll all be having mushrooms lined up on our windowsills and we'll also be waltzing around uh with our arms bare and maybe in some cases our torsos bare we have a a phrase in Glasgow taps af it's called which is take your top off in sunny weather so taps af then as soon as possible at least for some maybe not for the women listening um so thank you very much indeed it was a pleasure to listen to you um I'm very sorry indeed that uh I'm not able to hand uh the medal over to you on behalf of the society I um I think I'm shortly to become the the next president and that would have been one of my duties would have been to give you the medal the best I can do is this picture behind me it's the engraved medal it has your name along the bottom here and it will arrive in the post so a whole hearted thanks uh to you from all of us thank you very much I'm I'm very honored thank you very much