Vitamin C and kidney stones

This forum will focus on analyzing recent clinical studies of vitamin C.

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studentroland
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Vitamin C and kidney stones

Post Number:#1  Post by studentroland » Thu Feb 07, 2013 8:08 am

Hi. In feb. of this year a Swedish study regarding ascorbic acid supplements potential of increasing the risk for developing kidney stones was published in the JAMA journal, and also given room in the Swedish national television news programs. I´ve been looking in the books I have on the subject for a logical way of explaining to my neighbours why this study is not to be taken seriously, but have not yet found a logical way of doing that...is there anybody on this forum who can provide me with such an explanation, or show me where to find it? The study can be found here:
http://archinte.jamanetwork.com/article ... id=1568519
and it is talked about here:
http://ki.se/ki/jsp/polopoly.jsp;jsessi ... ewsdep=130

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Re: Vitamin C and kidney stones

Post Number:#2  Post by Johnwen » Thu Feb 07, 2013 9:56 am

We had this subject brought up many times and it is a unproven myth.
If you go to the link it'll take you to the last thread we did on this subject.




viewtopic.php?f=3&t=10607
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Re: Vitamin C and kidney stones

Post Number:#3  Post by majkinetor » Thu Feb 07, 2013 1:39 pm

Weak study. Not even need to discuss it. Even if true, benefits are multiple times better then perceived risk.

My personal opinion is that if you take Mg along with C, you R safe, even if you have some form genetic risk, or kidney disfunction associated with calcium/oxalate pathways.

http://www.orthomolecular.org/resources ... 9n04.shtml
http://knowledgeofhealth.com/modern-med ... lls-again/

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Re: Vitamin C and kidney stones

Post Number:#4  Post by studentroland » Thu Feb 07, 2013 4:48 pm

Thanks...I´ll look into this...I´ve got Linus Paulings book, and your link will also most likely be useful, so I´ll hopefully come up with a reasonable answer to my neighbour...:) thanks again...aaahhh...and I saw two new links...thanks...I´ll look into them aswell...I personally have followed Cathcart´s regiment for some years now, but today I found myself speechless when my ascorbic-acid critical neighbour smilingly said that this new study showed a double-risk of kidney-stones...I intuitively know that it´s not true, but I just couldn´t logically prove him wrong...but after having read all of these links I hopefully will...thanks again...:)

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Re: Vitamin C and kidney stones

Post Number:#5  Post by Dolev » Fri Feb 08, 2013 5:19 am

In 1996, Curhan from Harvard Med School published a very similar study and found that among 45,251 men, those who took 1500 mg or more of C compared to those taking 250 mg or less, "These data do not support an association between a high daily intake of vitamin C or vitamin B6 and the risk of stone formation, even when consumed in large doses." http://www.ncbi.nlm.nih.gov/pubmed/8618271

I have access only to the first page of the Swedish study, so I can't examine the data, and I have only a rudimentary knowledge of statistics, however, a couple of things I noticeds are:

1. the "sensitivity" of ascorbic acid use was only 67%, meaning that a third of the users were not identified, if I understand correctly.

2. the "specificity" was 93%, so 7% of users actually didn't use; again, I'm not sure if my understanding is correct. In any case, these figures lessen the accuracy of the results.

3. Studies based on questionnairs are not very accurate. How well do you remember what you took in the last year?

4. The headline of the article includes the words "Less is More". This shows bias in the report.

5. Out of 48,850 men, there were 436 first time cases of kidney stones, or less than 1%. I don't see the absolute risk data, but if there was a "2-fold" increase, that means that about 145 men taking vitamin C got kidney stones compared to about 290 that didn't, and that the vitamin C causes stones in about 145 men. So, about 0.3% had stones because of the vitamin, or one in 333. Pretty low risk, even if the study is completely accurate with no statistical innaccuracies, which is close to impossible.

Please point out mistakes I've made in this analysis. I'm very amatuer in statistics. I hope that Dr. Steven Hickey weighs in on this. By the way, his book, Tarnished Gold, is an absolute must for anyone who wants to not made a fool of by "evidence-based" statistical lies.
Dolev

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Re: Vitamin C and kidney stones

Post Number:#6  Post by studentroland » Fri Feb 08, 2013 8:14 am

Thanks "Dolev" for weighing in on this...this is where it gets a little "tricky" for me too, since I´m no expert in statistics...but my neighbour uses words such as the "risk" of getting kidneystones is "twice as high" if one uses ascorbic acid, a chain-of-words he´s got from the TV-news-coverage...Anyway...from the 48850 men I believe I can also see on the first side that they deducted for various reasons 1612, 5898 and 12873 men, leaving just 28467 men out-of-which these 436 with kidneystones were taken...? it is still less than 1% though...anyway, the above link to Bill Sardi´s article, leads one further to this article:
http://health.usnews.com/health-news/ne ... ney-stones
the author of which apparently could afford to read the entire published study...in it it says that only 900 men took supplementation with 1 gram vitamin C, and 31 of them (3%) developed kidneystones...apparently less than 2 % of the "larger group" (28467-900=27567?, 2% of which is 551?) also developed kidneystones without taking any vitamin C supplemetation.
Anyway, what I don´t understand is that this article also says that for the (900) 1 gram supplement-takers, there was an "increased risk" of 1.7 - 2.2 times of developing kidneystones, which is precisely what makes my neighbour say that what he says...but Bill Sardi has a much more credible reasoning in his article, although I don´t yet "get it" how he reaches those numbers...
http://knowledgeofhealth.com/
There is something in this reasoning that doesn´t make sense to me yet, since on Swedens most prestigious hospital where the study was undertaken, which I provided a link to in my first message, they write, quote:"The results of the study indicate that men who take vitamin C supplements (typically 1000 mg per tablet) are twice as likely to develop kidney stones as men who do not take any dietary supplements."unquote
Common sense tells me that there is some kind of statistical lying going on here, but I can´t pinpoint just how it is being done...yet...:)
"Twice as likely" to me intuitively makes me think that if this was true, and 900 men regularly ate 1 gram supplementation-doses of vitamin C, about 450 of them would develop kidneystones...this is obviously ridiculous, but lies at the very heart of the reasoning that I get into with my neighbour...

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Re: Vitamin C and kidney stones

Post Number:#7  Post by majkinetor » Fri Feb 08, 2013 1:57 pm

the author of which apparently could afford to read the entire published study

I guess there isn't much more then that 1 preview page... all the info you need is there.

Common sense tells me that there is some kind of statistical lying going on here, but I can´t pinpoint just how it is being done.

"Twice as likely" is just a scary tactics. If you risk is 0.00001% then 0.00002 is twice but its still meaninglessy low for clinical effects. Riordan clinic treated bunch of people with 100++g IV vitamin C with only 1 man developing kidney stones in 15 years (with history).

There is also that funny thing: supplemental users are more health consciousnesses so they will be diagnosed before other people. They say that pain with stones is so big that it excludes such phenomena. Yet, there is nothing which tells how the kidney stone was diagnosed - perhaps during routine scan, and there is no pain involved. I know lots of people with kidney stones without any pain whatsoever. Actually, I bet this is the main confounder. Its even probable that C megadosers often do kidney stone screening as of the constant vitamin c = kidney stone stories around. Everybody knows that - every person that finds out how much C I take, tells me about stones, even illiterate one.

But anyway, since multivitamin didn't increase risk, I guess its sensible to say to your neighbor that you don't take C alone but with multivitamin and other stuff, like you should.

But given that there are no well-documented benefits of taking high doses of vitamin C in the form of dietary supplements, the wisest thing might be not to take them at all, especially if you have suffered kidney stones previously."

This sentence show how well informed Agneta Akessonis!

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Re: Vitamin C and kidney stones

Post Number:#8  Post by studentroland » Fri Feb 08, 2013 4:28 pm

Hi. I finally, with the help of yáll and also by examining the article by Bill Sardi, have come up with the correct solution to my initial question...! The answer is; when my neighbour the next time brings up this study over a casual dinner-talk, or in some other circumstance hints at that there was a study which was talked about on national-TV the other day that says that vitaminC-users run a "double" risk of getting kidneystones, I can easily and logically prove him wrong, in a way that he understands, by saying that he has not yet understood the fact that what they were talking about on the news was the RELATIVE!!! risk that the people in the survey ran, but what he is trying to argue for is the ABSOLUTE risk for him or me...I didn´t know the difference between these two terms myself, until I tried to find the answer to my initial question, and my neighbour for sure doesn´t know the difference between them either...and obviously there are a whole host of news-reporters, writers on the Internet and reporters from all walks of life who reports on health-issues who don´t understand or use these terms, not the least of which are the very people writing on the Karolinska Institutes own web-site, where they write, quote:"The results of the study indicate that men who take vitamin C supplements (typically 1000 mg per tablet) are twice as likely to develop kidney stones as men who do not take any dietary supplements.", unquote, which simply is not true, because the fact of the matter is that "the results of the study indicates that men IN THE STUDY who take vitamin C supplements (typically 1000 mg per tablet) are twice as likely to develop AN INCREASED RELATIVE RISK FOR kidney stones as men IN THE STUDY who do not take any dietary supplements." The ABSOLUTE risk that the study might indicate for someone like me or my neighbour would probably be something like Bill Sardi says on his blog, 0.310%, or something in the neighbourhood of 1/6th of 1% or 1/3rd of 1%, I don´t know ...but the numbers aint the point here, the point is that for me to manage to discuss with my neighbour, or anyone else for that matter about scientific research and megadoses of vitamins and minerals, it is of vital importance for me to be able to explain the difference between what the scientists talks and writes about and sometimes manages to scare people off with, is the RELATIVE risk...and what concerns me healthwise, and also should concern my neighbour healthwise, is the ABSOLUTE risk...big difference, and one which mostly is obscure from written language, and certainly not talked about, because few people talk about it, I guess...:) but I will from here on, that´s for sure...:) ...thankyou all for participating on this issue...it helped me a lot, and I got my question answered to my satisfaction...very good...:)
One more thing...the "scientific lying" that I suspected was going on...? Lying by omission, it´s called...when one reports a scientific study, and fails to clearly state the relations between RELATIVE and ABSOLUTE risks, one will for sure run the very high risk of being accused of LYING BY OMISSION...:)

http://blogs.wsj.com/numbersguy/the-risk-numbers-1128/

"Relative risk is the ideal measure for statistical analysis, for addressing scientific questions," says Don Berry, a biostatistician at the University of Texas MD Anderson Cancer Center in Houston. "But it is irrelevant for individual decision-making."


I´ll have a look at the book "Tarnished Gold" also...it seems as if this book is "right up my alley" at the moment...:)
Last edited by studentroland on Fri Feb 15, 2013 6:11 am, edited 2 times in total.

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Re: Vitamin C and kidney stones

Post Number:#9  Post by VanCanada » Sun Feb 10, 2013 9:18 pm

The study you found should have controlled for the number of people in each group who handle vitamin C differently. It's unlikely the researchers controlled for this subgroup of the population.

Check out pages 80 to 83 of "Vitamin C: How Best to Use It" by Stephen Sheffrey.

Here is an excerpt:

Stephen Sheffrey wrote:People who form stones regularly handle C differently. They convert most of the ingested C to oxalate in the gut, then absorb the oxalate. It's as if they were living on spinach and rhubarb. This of course leads to stones if conditions are right. If most of it converts to oxalate, do stone-formers have enough C left to keep its blood level up? No. Regular stone-formers have low C levels, either due to oxalate conversion or malabsorption. When a group of stone-formers were given 500 mg of C intravenously they failed to pass the expected amount in the urine. The body needed it, therefore refused to give it up.(Ref. 30)
-Reference 30: Chalmers A H, Cowley D M, Brown J M. A possible etiological role for ascorbate in calculi formation. Clin Chem 1986; 32:333-6

- http://www.vitamincfoundation.org/forum/viewtopic.php?f=10&t=9503&p=27949&hilit=calculi+formation#p27949



Also, Dr. Thomas Levy addresses the oxalate issue on this forum here:http://www.vitamincfoundation.org/forum/viewtopic.php?f=3&t=7701&p=19277&hilit=encapsulated#p19277

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Re: Vitamin C and kidney stones

Post Number:#10  Post by studentroland » Mon Feb 11, 2013 7:17 am

Well, this was an interesting angle...what started out as a search for some logic vis-a-vis my neighbour, turns out to become a real learning-experience...:) ...I don´t have access to Dr. Sheffreys´book (yet?), but I read the link, and looked into the matter a little bit further, and combined with my earlier reading of Dr. Orian Truss´book, "The Missing Diagnosis" in which he outlines the disease called "Chronic Candidiasis" as, roughly speaking, being caused mainly by an intestinal overgrowth of the yeast/fungus Candida Albicans (among other fungi), and the fact that one of the metabolites of fungi is oxalate, I´d say it sounds reasonable to think that when someone has an overgrowth of fungi in the gut, ascorbic acid might very well be metabolised into oxalate by them, and then absorbed as Dr. Sheffrey says...so, the researchers in this study, probably led by Prof. em. Hans-Göran Tiselius who has done many other studies into the enigma of kidney-stones , most likely did not consider any subgroup where people metabolize ascorbic acid differently from others, as this probably is known only to people with a special interest in the metabolism of ascorbic acid...(as those present on this site?)

Anyway, I didn´t know it until you pointed it out to me, but since this other "obscure" hypothesis of Candidiasis as a cause for many diseases, e.g. the auto-immune ones, is also little known by the medical establishment, as is Hypoascorbemia, I would not be surprised if in fact "regular stone-formers" do have a fungal overgrowth in the gut, causing them to absorb more oxalate than others...

Since my initial question is solved to my own satisfaction, I´m now free to further look into this connection between ascorbic acid´s hypothesized degradation by some subgroup of people to oxalate already in the gut-lumen by existing overpopulation of fungi, and formation of kidney-stones... perhaps even Autism, as it is suggested on this site:
http://www.greatplainslaboratory.com/ho ... alates.asp

Furthermore, an overgrowth of yeast/fungi in the gut may also be accompanied by a degradation of normal bacterial gut-flora, for instance the oxalate-degrading species called "Oxalobacter formigenes"...
http://aem.asm.org/content/68/8/3841.full

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Re: Vitamin C and kidney stones

Post Number:#11  Post by ofonorow » Fri Mar 15, 2013 9:06 am

Yes, I second that notion that Hickey and Robert's TARNISHED GOLD is a must read and explains the fallacy that is "evidenced based medicine."

So to the question, what is the risk of vitamin C causing kidney stones?

a) If vitamin C (ascorbate) played a significant role, than why don't animals, the majority of which make their own ascorbate 24/7 in amounts about two orders of magnitude higher than the Government RDA, suffer kidney stones in great numbers?

b) As M- pointed out, kidney stones are virtually nonexistent in the two clinical practices that used the highest amount of sustained vitamin C. The Riordin clinic and Cathcart's practice.

c) Any discussion of oxalate a) only applies to a subset of the stones, and b) is probably not applicable given the Hoffer review of the Japanese who were unable to duplicate the oxalate results found all over medical text books. Dr. Sheffery was a terrific vitamin C supporter, but he was a dentist. He wrote under the assumption that medical textbooks were correct about the oxalate issue.

d) These fictional studies/stories in the media are aimed at medical doctors. They are designed to reinforce what is taught (or in this case not taught) in medical school. If they happen to sway members of the public away from taking vitamin C, all the better for Big Pharma.

e) If there really was such an effect, even on 1/16 of one percent of the population, it should be easy to conduct a repeatable experiment that shows it. Where are these experiments?

f) B6 and magnesium will prevent kidney stones from forming.

g) Pauling's book explains why about half the stones that form (in alkaline urine) are prevented by taking asorbic acid. And that for the stones that generally form in acidic urine, one would be prudent to take their vitamin C as the alkaline sodium ascorbate.
Owen R. Fonorow, Orthomolecular Naturopath
My statements have not been evaluated by the Food and Drug Administration. Any product mentioned is not intended to diagnose, treat, cure or prevent any disease.”


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