The Vitamin D debate with Professor Spector

hello everybody and my name is tim spector and welcome to dr john campbell um who's with us today to discuss a controversial topic uh that's around both in nutrition and in covid that i i and john as many of you know is a youtube star on this everyone's always going on about have i listened to his video and why don't i change my views uh because he's cl laid it out so clearly so i thought it's a great occasion for us to have a chat uh about vitamin d because i've obviously been working in the field for about uh 25 years uh on and off and was was certainly a big fan of it and but none of us are really experts on uh vitamin d and covid uh this is all new to everybody so um that's laying the framework but do you want to kick off and tell me why you think uh vitamin d is so good and why you take it regularly and what you know what's led you to to really start promoting it yeah thanks for the introduction tim and thanks for having me again it's great to talk um the the reason i started thinking about vitamin d really was that first of all it's an unusual sort of nutrient stroke pre-hormone so the vast majority or in fact all of the nutrients we we get all of the the essential let's call them vitamins that we need and the minerals that we need come from our diet now if you eat quite a lot of seal and fish liver and uh you have a basically an inuit type diet then you're probably going to get enough vitamin d in that diet but for most of us we don't perhaps 10 percent of my vitamin d requirement comes from my from my diet we just don't get a lot a lot so of course where vitamin d comes from is from the sun it's from the sunshine that the the skin synthesizes the vitamin d on exposure to ultraviolet b radiation and then the chemical form there trots off to the liver and the liver transpose into another form and then it shots off to the kidneys and then it's the kidneys that actually uh convert it into the most active form and of course in the old days i remember working with renal patients who had quite significant bony demineralization before before before this vitamin d problem was worked out in patients with kidney failure so we have it from the sun and the reason that it another reason this is so important is when humans first started migrating into europe presumably and i think pretty well most geneticists would agree on this tim might comment but we were dark-skinned so the original humans were dark-skinned if we come from africa in the middle east we'd have dark-skinned human beings migrating north and the only real selective advantage to to developing a white skin over presumably a few thousand years of human change in evolution is that the white skin produces vitamin d in well if you take my skin uh compared to a a dark african skin i'd probably make vitamin d say 20 times quicker so so that is the big adaptive advantage now why would this be selected in if there wasn't a good reason for it and then we can combine this with some modern biochemistry and again tim knows much more about this than i do but my understanding is that certainly there's vitamin d receptors i believe in all of the immunological cells and potentially vitamin d receptors uh in in all cells in the body some people say uh that's my understanding so there's vitamin d receptors all over the place which indicates that it's really quite important and then you take together with the fact that a lot of us um wear clothes all the time we tend to work indoors um i live way up in carlisle near the scottish border um and basically we don't make vitamin d in significant amounts until the sun's about 45 degrees in the sky which of course a lot of the time here it isn't and then if you take studies from the states and studies from the uk um serum vitamin d the active form of vitamin d levels we find that the the active form of vitamin d levels are really quite low low compared to people who would live in in sunnier environments whereas people who live in sunnier environments and exposed to the sun um have have a higher levels of vitamin d so a lot of things kind of came together really to indicate that this is important and then i started reading some data that shows uh studies that have been done with people with low levels of vitamin d who are somewhat more prone to influenza where the studies have been done and and then vitamin d implicated in other forms of immunity and that then that sort of started me thinking about the vitamin d and the covet are we deficient in vitamin d is this leading to immunocompromise and then as the covered went on really we learned this about last last february or so it seemed that a lot of the complications of covert 19 weren't so much occurring in the first week where there was a significant viral phase of the illness but was more occurring later on when there was an inflammatory stage of the illness and the alveoli were filling up with fluid for inflammatory reasons and then of course we learned that vitamin d is an immunomodulator so low levels of vitamin d could uh inhibit immunity but low levels of vitamin d could also allow inflammation to become uh somewhat rampant leading to this now uh infamous uh cytokine storm so that immunomodulatory effect seemed to come together but it could go on this for quite a quite a while but uh disagreed with you much so far but there's a killer point coming somewhere yeah it's called course or cause or consequence and you know 20 years ago when i was starting out on vitamin d i i was i believed it was the the cure for everything from depression fibromyalgia rheumatoid arthritis osteoporosis which i was uh an expert in and um was prescribing it all over the place and at least a hundred diseases have been associated with low vitamin d levels and because definitely if you're sick and you've got a chronic disease or perhaps a severe acute disease uh your levels go down and so the this association was made this is absolutely crucial and therefore and i'm not disagreeing we need vitamin d uh although uh most people don't call it vitamin anymore but it's um it's a sort of steroid um the question is if we've got slightly low levels and we give people more does it make any difference to my mind that's the that's the key thing here and then as soon as we've gone to randomized trials for these hundred diseases we basically fail to find any evidence that it works so the observational studies are both the vitamin d levels and uh your baseline level and and developing a disease are generally all positive i show a link between the disease and vitamin d as soon as you do a randomized controlled trial you give people dummy vitamin d other ones and i've done a couple of these myself um ages ago you don't actually see a difference in bone density or all that or whatever it is so and i think we're going to see the same thing uh with covid and that my view is that you know everyone loves vitamins we love a simple solution i think vitamin d is probably the most favor everyone's favorite vitamin the sunshine bitterness yeah you know you can get it free just by going outside on a nice you know spring or summer's day and 15 minutes you're topped up it's brilliant and you know so it's got a natural pr company working for it uh as well as the billion dollar industry that also supports it so that so i was i was interested um to see if because then there's several issues here one is what is the normal level of vitamin d and then does giving chemical supplements to increase that actually have the same effect as uh increasing your natural levels anyway and that's the other whole question that comes in here with um with supplements is are they as good as eating the food or having the sunshine and i think that's really not resolved and there are definitely some evidence that i've been reading that you know broccoli extract sulforaphone is not as effective as broccoli having calcium tablets is probably harmful to you relative to drinking milk or having you know getting the calcium from your vegetables so they're the issues that i i i'm that concerned me and uh and there's some other evidence which we can talk about mendelian randomization but um what are your thoughts on that cause the consequence and how good is the data on covid for example in uh with with those things in mind because i think you probably read the the recent literature more than i have yeah um just can i ask a question first time just to clarify my own thinking i mean how well documented is it that acute disease results in an acute reduction in vitamin d levels because this is not something that's in the medical textbooks you know you don't read about particular diseases and then it says one of the clinical indicators of this is low vitamin d levels this is not is is this something that sort of well established it in medicine or or where is the state of you know when you're reading about um you know anything you know you're reading about sepsis it'll say well that goes up and that goes down and that stays the same we don't see that in the medical literature for vitamin d levels as a biochemical signature or a sign of of acute disease or do we could correct me well i think it's partly because vitamin d lev testing only came in uh about 20 years ago when i started my career really wasn't possible to get the test and then it took about two weeks to get a result so uh by the time you've worked out with the patient's getting worse you know it's all past history so it's not it's not used like a like a getting your electrolytes measured or getting your esr or your white cell count so i think it's never been used in the acute setting so we don't have much data on that we do know from lots and lots of case control studies that once you've had a chronic disease or an illness nearly everybody is low compared to the healthy control group so that it's a non-specific sign and that's why everyone you know with lots of diseases like fibromyalgia or depression would have low vitamin d levels and everyone thought well we've got to treat them that's going to cure the depression or the muscle pains or whatever it was and whenever they did the randomized trials it failed so it seems to be a common theme that vitamin d levels are changing uh due to the general stage of the body maybe as an adaptation maybe because of other proteins sticking to them we don't know but i think that's that's my understanding there may be some acute studies that i'm aware of but it's because you can't you can't get a result quickly it's not of use to a clinician i think that's the main yeah the main reason i mean i've worked recently in a e and we don't routinely measure vitamin d levels and uh talking to colleagues in intensive care again they don't routinely measure this so i i think the contention that acute illness results in a reduction in vitamin d level is one where we probably still need some more evidence i would think but it's certainly an interesting one to look at two thoughts come to my mind there people that are acutely ill firstly do they tend to spend more time indoors in hospital secondly our people acutely ill more often in wintertime when of course even down there in sunny london you're not going to be making vitamin d uh for for perhaps seven or eight months of the year at the best of times and the other one that's really intriguing is is is vitamin d such an important molecule that it's actually used up in acute illness um a bit like using up reserves of energy or reserves of glucose or of course i mean when people are acutely ill that they can you lose several kilos of protein when they're where they're acutely ill so again i think the cause and effect argument kind of kind of works both ways on that and it'd be interesting to find some some more knowledge on that but but i'm not dodging your question um the the the you are 100 right there is no uh firm clinical trial data now there are small cell clinical trials that they're conducting very badly and uh that that actually brings up another point large-scale clinical trials that are very well conducted often conducted in cooperation with uh big big pharmacy companies uh produce brilliant papers the peer reviewers will all love it and of course they'll get published in the best quality journals but a lot of the research that's been done around the world on new therapeutics for example for covid and uh and indeed vitamin d have often been done at the clinician level the study in spain for example the chord of a study there was a small scale study that you know of and uh the results from that appeared to be positive so they did a larger scale study and the paper was published in that as you know it was later withdrawn because of methodological problems but that's not surprising because the the methodologies was devised by the clinicians themselves while they're doing another full-time job rather than being organized and of course the problem is vitamin d is a generic molecule you can't paint it and you can't make money out of you can make some money out of selling it but basically you can get it for you know some people make a lot of money out of selling it i get mine from several local supermarket chains most of it comes from china i think most of the attractions vitamin d factories and i think i think there's big qualities questions there on the quality of that as well which is another issue but i think there's almost an inbuilt bias in the scientific system that that promotes people that can afford to do big scale clinical trials who stand to make profit out of it whereas the trials that we say are are not so well conducted basically because they're not so well conducted but but you're no clinicians like i do have funded their own research and done it at weekends um so yeah for those studies when the equivalent would be in uh respiratory infections and those you probably know there was a metro analysis of about 20 small studies of vitamin d uh can it prevent respiratory infections flu etc which people thought was the best the most closest you could get to uh coven and that was the reason i think a lot of people got excited and the uh the original one was done on about 12 um studies and published and there's a new one out on many archive which is preprint where they expanded this list to about 20 and that unfortunately the protective effect dropped from about 20 uh or 25 down to about 11 and they also said a lot of the studies were very poor quality and if you took them out uh it actually dropped even further so it you know we are lacking i think an evidence base to uh really rely on vitamin d and of course uh we've got a paper uh coming out this week um which i i gave you a little look at i i have the pre-print here yeah yeah um where it wasn't a small study by any of any means um we had point four million one point four million people uh who use the zoe app so thank you very much if you're if you're listening your data was incredibly valuable whether you were taking a supplement and in this case vitamin d at the beginning of the pandemic and whether you got covered uh or not uh later on in in in the six months that followed it and uh basically we we found rather hard to interpret results i think but i i'll ask you in a second um basically we found that there was uh an overall weak benefit but in terms of slightly reducing uh the risk of of getting covered but zero effect in men and about a nine or ten percent effect in women once you've adjusted for all the other factors so there were two we thought there were two conclusions one it's real and there is a small effect that only affects the immune systems of women or b that's highly unlikely biologically and we think it's a selection bias possibly because women go to the pharmacy and they buy the vitamins for the whole family but i'd love to hear your take on it john yeah yeah um i did read that study and i was absolutely aghast this difference now we know that there's some differences in the immune system of men versus women but basically we're both human beings you know and to have such a dramatic difference would really surprise me so i i really suspect that that difference between the protective effect of women and the non-protective effect in men that was was picked up there is not going to be explained by fundamental biological differences between between men and women so um interesting study you know i'd be in fascinating if it's been peer reviewed it'd be interesting to see what the peer reviewers uh say on that but the idea of collecting data from 1.4 million no tim is just absolutely marvelous and this is exactly what we need this large-scale study but there is kind of a but on this even though you've got very large numbers you know we have to you know you have to ask the right questions to be able to interrogate the data correctly and um i think i think that question does need answer the differences between men and women so so that that will be interesting but as well as that we need to look at it in context of other studies now i i'm aware i didn't fully answer your question before so part of the reason that i really got onto this vitamin d thing and i personally i'm i think there's an immunoprotective effect at the moment that is where i'm currently at uh was the bradford hill criteria so um i used to inflict bradford hill criteria from the students and forced them to write essays about it but the the you know the the the story austin bradford hill and richard doll of course discovered the relationship with smoking and lung cancer and then smoking and heart disease so bradford hill was very aware of the fact that some things are initially picked up as correlations and of course you know chapter one verse one paragraph one of the research manual says correlations are not causality we know that but but you know that they brought forward things like the strength of the correlation now that that does seem to be there with vitamin d to some extent now i know we could argue about vitamin d levels and how likely you are to get the infection although i think there is some positive evidence there from the british biobank study um indicating a protective effect but what seems to be the case is that people with the lowest levels of vitamin d and as you're right you say tim what is the normal level who would dare say what the normal level is um but people who had lower levels you know in in the lower quarter compared to the top quarter were more likely to become acutely ill more likely to go to intensive care in some studies and obviously a lot of those are observational studies so if you've got kind of a strength of correlation there that people with the very lowest levels of vitamin d are at risk now i think that there's a lot of precedent for this so um if you're feeling fine and i give you a lot of vitamin d like linus pauling used to take eight grams a day apparently the nobel prize winning i think american biochemist you know preposterous amounts and all you do is is we it out quite honestly isn't it you know it um so he he was taking huge amounts and having no effect at all but if you have someone who has scurvy and you give them a relatively small amount of vitamin c to bring them up then that that's going to take the symptoms away and we've got an analogy for this as well for so for example um you you'll know much more about this than me but the the the condition we used to call pernicious anemia i think we now call it autoimmune gastritis where the stomach is not producing what's what's called the intrinsic factor so the extrinsic factor which is the vitamin b12 can't bind to it and people end up with vitamin b12 deficiency which is a again it's a single nutrient but if people are deficient of it giving that basically get gets rid of the problem or if people have night blindness and we give them vitamin a or you know they have berry berry and we give them um vitamin b and and of course the the other the other one that came out i remember when this data came out it must have been late 80s i think on folic acid and neural tube defects in pregnancy where deficiency again there of a single nutrient uh i think i think rectifying the deficiency in folic acid reduce neural tube defects by about 70 percent so we're talking about spina bifida there so i i think that's well that's all extreme cases now i'm absolutely agreeing with those examples yeah right and you know that really i mean the whole of nutrition advice and supplements is based on really the scurvy story you know you could transform a rabble of crew that were doing nothing and have leading guns of a useless into a fighting force and that that's really the story of it but the question is if you've got levels that are reasonable which most people have you know 95 population have reasonable functioning levels for them because i don't think we've defined what a normal vitamin d level is uh i think there was a lot of hype creating a disease where half the population deficient and that's just nonsense um because they don't have any sign of it other than this blood level being low and everyone is different because we do a genetic study showing that your vitamin d levels are about 50 genetic and you can actually we you can actually look at the genes and they explain 50 of them we've got worked out about 10 of them and when you put those into studies to see like in biobank a colleague of mine in canada brent richards did this and his paper which is in preprint shows no no benefit on on on covert in in in biobank so genetic levels baseline levels where you are don't seem to relate uh to that and he's used that method um to re show there's no effect on fractures um and show there might be an effect a positive effect on multiple sclerosis so um it's another tool that we have at our disposal so i think we can argue all day about what a normal vitamin d level is and it's largely historical the way it was calculated and you know as it was titrated with calcium and pth levels in the blood which is a bit too technical to go into but um i don't think anyone's really ever correlated those with clinical signs and my view of the whole immunology thing is you know there's been a lot of hype about immune boosters and all this kind of stuff yeah if you've got terrible zinc deficiency and you're one in a million people with zinc deficiency your immune system might be rubbish um because everyone needs tiny amounts of zinc but do we need extra boosters of zinc for normal people the answer is no uh although it's in a lot of our food supply you know so there's a there's an idea that that tiny example you know that 0.1 percent of the population that definitely have a problem can be generalized to everyone else that's where i think the problem is and that's why we're overselling a lot of these supplements and for me the danger is if you oversell the supplement you undersell real food and environmental and lifestyle factors to be healthy and i think that's that's the danger of embracing all these quick fix um supplements you know think thinking of vitamin d is gonna uh prevent you getting covered or getting serious covered when actually you know the lifestyle or your as we're gonna find out soon from our data your diet quality is probably much more important so that that's that's my uh take on this but uh do you wanna have a final word on this before we um no it just raises so such interesting questions um so so basically i think what you're saying there tim is your research is showing that there's no such thing as a normal vitamin d level necessarily that what might be normal and healthy for you it could be too high or too low for me so is that is that that's right you keep finding you've got a low level yourself i remember on one of your videos yeah yeah and you find it really hard to get it higher yeah well maybe that's because your body's saying well i've got quite enough for me thank you i don't need any more of this rubbish um my gene for my genes and my body you know i've done i'm doing okay thank you um so i think it it makes the whole thing much you know much more complex and personalized an individualized homeostatic level i mean you mentioned pth there which is the parathyroid hormone of course and this is all to do with the vitamin d and the hormonal regulation of calcium levels so so what i think what you're saying is the low calcium levels are probably going to be quite consistent because it's an electrolyte that's needed for the normal functioning of cells the same as sodium and potassium but the regulators that go around that like the vitamin d different individuals could potentially need different levels so it's very hard to say what is a normal for the population therefore it's hard to say that people are high or low is that that's it's an interesting new perspective so yeah what's our consensus do you think do you think we can uh agree uh a lot of people you know look to us for advice and um it's pretty frightening we've come from other opposite camps if you like on this uh i presume you're still gonna be taking your your vitamin d i'm still gonna be taking it until the sun comes out and i can get my shirt off at the allotment and start making some in my skin because i just don't get enough i don't get enough from my diet but could we agree that people that have very low levels of vitamin d have a sub-optimal immune system if their levels are very low yes if it's extremely low but those people i'd say you know less than one in 100 people not not the 50 percent that you know their industry claims are deficient and need these sort of treatments we need to need to be so careful about people pushing a particular product on us because they make money of it and of course the food industry is replete with these kind of examples i think we could probably agree on this as well um that the immune system is an amazing mind-blowing incomprehensible physiological system to me and if it's working well if it's working at its optimum physiological levels i know of no way of boosting that no way of improving that if it's working at its physiological best but i do know of several deficiencies for example protein deficiency or other deficiencies or other problems which would actually lower the efficiency of the immune system so i think what we're always trying to do is to optimize the efficiency of the immune system but once it's optimized i don't think i know of anything that can boost it beyond that optimum level um do you well we don't quite know what the optimum level is i guess that's the downside so the only i'm agreeing 95 any caveat i would have is i think there's increasing evidence that your gut microbiome quality is probably the maybe the number one factor that influences your immune system so if you get your diet in order and you do all the things that are good for your gut microbiome you will you have the optimum immune system and then it's getting those three things working together that is the best way i think uh to uh you know get your best possible defenses against the infections and overreaction autoimmunity et cetera so we're still in the early stages of fathoming this out but i think i'd rather we took a holistic picture on this and but basically with a diverse healthy diet and trips to the sunshine um i think we can uh we can stay as healthy as we can be and i'll be getting a trip to the sunshine just as soon as i can in the north of england

Channel: Dr. John Campbell

Views: 168,898

Rating: 4.8739157 out of 5

Keywords: physiology, nursing, NCLEX, health, disease, biology, medicine, nurse education, medical education, pathophysiology, campbell, human biology, human body

Id: aCAvvZXUW08

Length: 30min 48sec (1848 seconds)

Published: Tue Apr 06 2021

Reddit Comments

[u/rmaccr]

Take your vit.D?????