This is rather interesting...

[Lainie71]

Bit long winded but worth a listen.

 

[Oldvatr]

Sadly he is using the same statistical methodology as the NHs which is Hazard Ratios and Relative Risk which ends up being interpreted that 76% of people being treated with Vitamin D will escape diabetes. Sounds inmpressive, but he does at least give the number to treat as being 30 to save one perrson, so 29 will not be saved.

Yes Vitamin D is vital to all of us especially in the temperate climes. But if this theory is valid then there would be a noticeable difference between those in temperate zones vs those where there is sufficient sunlight to boost vitamin D. There would also be a difference between those on a plant based vegetarian diet vs omnivores since the vegetable D is not as bioavailable as the animal sourced version (D2 vs D3 and also the low levels of plant based K2.

Mushrooms are a very good source of D but not if they are cooked. They are best when left to fester in sunlight which boosts the D levels. My GP refuses to provide cholecalciferol for me even though I am almost housebound now. My chemist does sell a small spray bottle of D3 but at £20 a bottle but I see their website is offering another one at around £10 so I suspect the price they quoted me is for the NHS supplied one that my wife used to get on scrip.. However there is a disclaimer on the cheaper one in that they do not guarantee the quality since it is not under their control.

But the evidence is for those likely to get to T2D stage, but does not seem to help those of us already in the race.

 

[Lainie71]

Sadly he is using the same statistical methodology as the NHs which is Hazard Ratios and Relative Risk which ends up being interpreted that 76% of people being treated with Vitamin D will escape diabetes. Sounds inmpressive, but he does at least give the number to treat as being 30 to save one perrson, so 29 will not be saved.

Yes Vitamin D is vital to all of us especially in the temperate climes. But if this theory is valid then there would be a noticeable difference between those in temperate zones vs those where there is sufficient sunlight to boost vitamin D. There would also be a difference between those on a plant based vegetarian diet vs omnivores since the vegetable D is not as bioavailable as the animal sourced version (D2 vs D3 and also the low levels of plant based K2.

Mushrooms are a very good source of D but not if they are cooked. They are best when left to fester in sunlight which boosts the D levels. My GP refuses to provide cholecalciferol for me even though I am almost housebound now. My chemist does sell a small spray bottle of D3 but at £20 a bottle but I see their website is offering another one at around £10 so I suspect the price they quoted me is for the NHS supplied one that my wife used to get on scrip.. However there is a disclaimer on the cheaper one in that they do not guarantee the quality since it is not under their control.

But the evidence is for those likely to get to T2D stage, but does not seem to help those of us already in the race.

Very interesting though and as I prefer my mushrooms raw I will let them sunbathe a bit before eating! I couldn't take a Vitamin D supplement as it made be feel dizzy and sick within 48hrs. But no you are right, it will more than likely not help those of us already in the race.

 

[Oldvatr]

If the Number to Treat is 30 then that is 3% which is more realistic than the 76% claimed in the video. I find that in general, the Relative Risk is about 10x exaggeration of the actual benefit.

 

[Mbaker]

If the Number to Treat is 30 then that is 3% which is more realistic than the 76% claimed in the video. I find that in general, the Relative Risk is about 10x exaggeration of the actual benefit.

Relative risk should be banned, as it is the smoke and mirrors used to exaggerate usually tortured confounded data. If I earn £100.00 and someone says you are going to get a 10% pay increase, I expected my pay to be £110.00 (absolute amount), the relative 10% might be £101.00. This nonsense should not be acceptable.

 

[Oldvatr]

Relative risk should be banned, as it is the smoke and mirrors used to exaggerate usually tortured confounded data. If I earn £100.00 and someone says you are going to get a 10% pay increase, I expected my pay to be £110.00 (absolute amount), the relative 10% might be £101.00. This nonsense should not be acceptable.

Indeed. The other problems I see are that the restrictred trials on only prediabetics is being extended to the general public but this makes it no longer relative since the conditions are different. Secondly the assumption is made that prediabetes always progresses to full blown diabetes (100%). RR only works if the data sets are homogenous and there us usually a set of tests that must be applied to test this ad this info seems to be missing. You can only compare like for like. The last issue I have is that the results are amortised over 3 years but that does not mean the RR is reduced by the time period. The risk is due to D3 vs No D3 not how long you take it.

 

[Oldvatr]

There's an elephant in the room. The dear doctor bangs on about there being x diabetics in USA and y in the UK. The studies he references are on prediabetics only and the primary outcome is the number who went on to full blown T2D. The studies do not cover anyone already DX'ed as diabetic, for whom that evidence offers no succour. So the expansion even to the diabetes population as a justification for demanding Vit D testing is not upheld. So those of us with a diagnosis - keep taking the medicine. Taking Vitamin D supplement is optional.

 

[plantae]

Relative risk should be banned, as it is the smoke and mirrors used to exaggerate usually tortured confounded data. If I earn £100.00 and someone says you are going to get a 10% pay increase, I expected my pay to be £110.00 (absolute amount), the relative 10% might be £101.00. This nonsense should not be acceptable.

Why are we talking about relative risk when the paper the video is referencing talks about uses absolute risk?

 

[Oldvatr]

Why are we talking about relative risk when the paper the video is referencing talks about uses absolute risk?

When someone in a video is claiming a 76% success rate then it is wise to be suspicious.
I cannot find the referenced paper on the net, but did find this one which claims a 10% rate which is a bit more realistic.

Vitamin D and risk of type 2 diabetes

Supplements had no clinically meaningful effect in the latest trial Type 2 diabetes mellitus (T2DM) is a public health disaster; it affects approximately 480 million people worldwide, predicted to increase to 700 million by 2045.1 Another half a billion people have impaired glucose tolerance,2...

www.bmj.com

There is also a note in this paper that supplements did not show any significant improvement. The vitamin D administered was the analogue version i,e, the synthetic.

The paper in the video did not show up in any search. Does anyone have a link to the actual paper?
OK this seems tro be the one

Effects of Vitamin D Supplementation on Prevention of Type 2 Diabetes in Patients With Prediabetes: A Systematic Review and Meta-analysis

BACKGROUND. While observational studies have shown an association between vitamin D insufficiency and diabetes, it is unclear whether intervention with vitamin

diabetesjournals.org

Note it uses Risk /ratio throughout and does not use absolute. It certainnly does not claim 76% risk reduction. The conclusion uses the term "may reduce" when talking about supplementation.

I think the doctor in the video is talking above his pay grade.

 

[CatsFive]

Quite a few years ago I was diagnosed as vitamin D deficient. It wasn't surprising really - I'd moved from 53N to 56N and whilst I was spending as much time outside I was rather more wrapped up due to a change in activity. I started taking Vitamin D brought on Amazon - the GP could only offer it in with calcium. My last order was for 365 tablets of 4000iu D3 plus some K2, and it was £22 - pence per day.

Once established on the tablets I felt better and got many fewer migraine-like headaches. However I still recently developed T2.

It's good to see a serious critique of one of Dr Campbells videos. He made a big name for himself during lockdown, and I wonder how many people think he is a doctor of medicine such as a GP? He is actually a PhD. "My PhD focused on the development of open learning resources for nurses nationally and internationally." Not sure how much statistics is in that thesis.

 

[Oldvatr]

Quite a few years ago I was diagnosed as vitamin D deficient. It wasn't surprising really - I'd moved from 53N to 56N and whilst I was spending as much time outside I was rather more wrapped up due to a change in activity. I started taking Vitamin D brought on Amazon - the GP could only offer it in with calcium. My last order was for 365 tablets of 4000iu D3 plus some K2, and it was £22 - pence per day.

Once established on the tablets I felt better and got many fewer migraine-like headaches. However I still recently developed T2.

It's good to see a serious critique of one of Dr Campbells videos. He made a big name for himself during lockdown, and I wonder how many people think he is a doctor of medicine such as a GP? He is actually a PhD. "My PhD focused on the development of open learning resources for nurses nationally and internationally." Not sure how much statistics is in that thesis.

Indeed

John Campbell articles analyzed - Health Feedback

healthfeedback.org

Seems i was right to be suspicious. Others also find his claims to be off the mark.

 

[liarsdance]

I concur. John Campbell is not a medic but a nurse and academic. Nothing wrong with that of course - I too am a (now retired) nurse and academic. In fact we did the same CertEd course in the late 80s. But certainly many of his followers believe him to be a clinician.

 

[Oldvatr]

I concur. John Campbell is not a medic but a nurse and academic. Nothing wrong with that of course - I too am a (now retired) nurse and academic. In fact we did the same CertEd course in the late 80s. But certainly many of his followers believe him to be a clinician.

The problem is that he is putting out information that is profoundly distorted, It is clear to me that he is prone to over exaggeration and his messages could be considered harmful. in this case taking vit D is probably worthwhile and only hurts the pocketbook if it is not needed.

I think the paper I linked gives a better overview of the matter and I find it more believable. Yu Zhang is a reknowned research fellow in the field of diabetes research and has produced many studies that are worth reading,

 

[Mbaker]

Why are we talking about relative risk when the paper the video is referencing talks about uses absolute risk?

My point stands, the average Josephine or Jo takes for example the WHO / IARC claim that eating 50 grams of bacon will increase the risk of colon cancer by 18% to mean a real 18 more cases per 100 - simply put that is a lie, there is no other word for it. Additionally one has to accept the methods, bias etc. Was an RCT double blinded of many persons some on bacon only and others on a standard diet to compare results. The food frequency questionaires are just the beginning of the limitations of such studies, then saying things like Pizza is meat, ignoring what goes with the bacon (it will always have some carbs such as fries, rice, potatoes, pasta etc). After a while and seeing studies taken apart by the likes of Zoe Harcombe and Bart Kay, studies can show what the authors / backers want.

 

[plantae]

My point stands, the average Josephine or Jo takes for example the WHO / IARC claim that eating 50 grams of bacon will increase the risk of colon cancer by 18% to mean a real 18 more cases per 100 - simply put that is a lie, there is no other word for it. Additionally one has to accept the methods, bias etc. Was an RCT double blinded of many persons some on bacon only and others on a standard diet to compare results. The food frequency questionaires are just the beginning of the limitations of such studies, then saying things like Pizza is meat, ignoring what goes with the bacon (it will always have some carbs such as fries, rice, potatoes, pasta etc). After a while and seeing studies taken apart by the likes of Zoe Harcombe and Bart Kay, studies can show what the authors / backers want.

I don't disagree. But the study refers to absolute risk not relative risk (apparently). It's a metastudy of three RCTs on different doses of Vitamin D.

Three randomized trials were included, which tested cholecalciferol, 20 000 IU (500 mcg) weekly; cholecalciferol, 4000 IU (100 mcg) daily; or eldecalcitol, 0.75 mcg daily, versus matching placebos.

Limitations include:

a) Studies of people with prediabetes do not apply to the general population
b) Trials may not have been powered for safety outcomes.

and my own addition:
c) It's pay-walled so it cannot be evaluated properly

 

[Mbaker]

I don't disagree. But the study refers to absolute risk not relative risk (apparently). It's a metastudy of three RCTs on different doses of Vitamin D.

Limitations include:

and my own addition:
c) It's pay-walled so it cannot be evaluated properly

And you believe the number. All of this is the context of the nonsense around staying out of the sun, splashing on sun screen and taking a pill. I would prefer adequate natural dosing of sun exposure, focusing on foods with vitamin d and topping up as needed. Metastudies drive me nuts, as depending on the statistical engine used you can make 10 insignificant (statistically) studies appear significant - more slight of hand. So much wrong there again, with P values and signal to noise just being ignored. The most telling thing is that we now have the most amount of data at our finger tips and yet the advice does not correlate with either common sense or better outcomes compared to what our grand parents saw. My view is that Vitamin D is vital and a priority, consider how this was viewed over the last 2 to 3 years.

 

[plantae]

And you believe the number. All of this is the context of the nonsense around staying out of the sun, splashing on sun screen and taking a pill. I would prefer adequate natural dosing of sun exposure, focusing on foods with vitamin d and topping up as needed. Metastudies drive me nuts, as depending on the statistical engine used you can make 10 insignificant (statistically) studies appear significant - more slight of hand. So much wrong there again, with P values and signal to noise just being ignored. The most telling thing is that we now have the most amount of data at our finger tips and yet the advice does not correlate with either common sense or better outcomes compared to what our grand parents saw. My view is that Vitamin D is vital and a priority, consider how this was viewed over the last 2 to 3 years.

I didn't say if I believed the number or not. I can't evaluate that because the study is hidden behind a paywall. I said that the study purports to be talking about absolute risk not relative risk

Edit: why don't we just get rid of p-values as well? They're abused just as much, if not more, than absolute and relative risk

 

[Oldvatr]

I don't disagree. But the study refers to absolute risk not relative risk (apparently). It's a metastudy of three RCTs on different doses of Vitamin D.

Limitations include:

and my own addition:
c) It's pay-walled so it cannot be evaluated properly

The study only had relative (RR) values. It was the video that is claiming absolute values, and there is suspicion that the absolute risk ends up much higher than the RR values in the report. So I strongly suspect the way the presenter has worked out his figures. To claim 76% success rate from a meta study is wrong. The meta study I found for this group of prediabetes published in 2020 found no atrong correlation for vitamin D supplementation. There is no other meta study showing for this group that i could find in my searches.

The following is an example of how relative risk can mislead

Absolute and relative risk

Absolute risk is the number of people experiencing an event in relation to the population at large. Relative risk is a comparison between two groups of people or in the same group of people over time. Knowing which type of risk is being reported is important in understanding the magnitude of the...

www.iwh.on.ca

 

[Oldvatr]

The paper in the video is 2021 and there is nothing showing in Research Gate.for it, but I have found a few papers published after this one that are of interest too

Vitamin D and risk of type 2 diabetes

Supplements had no clinically meaningful effect in the latest trial Type 2 diabetes mellitus (T2DM) is a public health disaster; it affects approximately 480 million people worldwide, predicted to increase to 700 million by 2045.1 Another half a billion people have impaired glucose tolerance,2...

www.bmj.com

What is the impact of vitamin D supplementation on glycemic control in people with type-2 diabetes: a systematic review and meta-analysis of randomized controlled trails - BMC Endocrine Disorders

Background There is conflicting evidence on the effect of vitamin D on glycemic control. Therefore, in the current meta-analyses, we aimed to assess the effect of vitamin D supplementation on the glycemic control of type 2 diabetes (T2D) patients. Methods We conducted a comprehensive search in...

bmcendocrdisord.biomedcentral.com

Controversial Impact of Vitamin D Supplementation on Reducing Insulin Resistance and Prevention of Type 2 Diabetes in Patients with Prediabetes: A Systematic Review

Background: Prediabetes has become a worldwide health problem. Multiple clinical trials have been conducted to determine the potential benefits of vitamin D supplementation in preventing the conversion to diabetes, but the results are inconsistent. The aims of this study were to evaluate the...

www.mdpi.com

Since we seem to have no access to the one in the video, we cannot know for certain what it actually stated and all we have is the words from the presenter.

Edit to add one more telling script

Vitamin D 20,000 IU per Week for Five Years Does Not Prevent Progression From Prediabetes to Diabetes - PubMed

In subjects without vitamin D deficiency, vitamin D supplementation is unlikely to prevent progression from prediabetes to diabetes. Very large studies with inclusion of vitamin D-deficient subjects will probably be needed to show such a putative effect. This study tested if supplementation with...

pubmed.ncbi.nlm.nih.gov

 

[bulkbiker]

Seems i was right to be suspicious. Others also find his claims to be off the mark.

Not sure I'd use an organisation with so few medics on the board as evidence of anything.. (not that I think medics are the be all and end all) but this mob seem to be pretty much focussed on "climate change" politics.