[RootedRedwood]

Check out this news article about the new Cochrane review that just came out that evaluates the risks/benefits of taking beta-carotene, vitamin A, vitamin C, vitamin E, and selenium.

http://www.cnn.com/2008/HEALTH/diet....lth/index.html

I just "love" how the nutritionist and MD that work for the supplement industry pass off the research as "flawed". Hmmm....I wonder who is biased there? I thought Cochrane reviews were the gold standard of research?

[hpcat]

I saw a web video on this - they think it's mainly the folks who OD on the stuff. I do know someone, a friend of my mom, who's taken a LOT of "healthy" things like that for many. He's in the worst health of anyone I know. Hmmm...

[nightmare]

Some vits are water soluble, some are fat soluble you take too much of the fat soluble ones you can OD .If you ate a whole Polar bear's liver,for instance,because it is packed with vit.E ,you would die,apparently!

[sauceywolf]

If you do some research you discover that the "study" took 452 pts and then after the "study" was complete, deleted over 90% of the pts (the ones who didn't die) and the remaining ones were already either terminally ill or end stage chronic illness who ended up dying anyway--voila! it must have been the vitamins that killed them!! What kind of sham science is this???

[RootedRedwood]

Originally Posted by sauceywolf

If you do some research you discover that the "study" took 452 pts and then after the "study" was complete, deleted over 90% of the pts (the ones who didn't die) and the remaining ones were already either terminally ill or end stage chronic illness who ended up dying anyway--voila! it must have been the vitamins that killed them!! What kind of sham science is this???

"The study looked at 67 medical trials, involving 232,550 people, most of whom were taking a high-dose antioxidant because they had a health problem, such as heart disease, gastrointestinal ailments or neurological complaints.
Overall, 13.1 per cent of participants who were taking an antioxidant died, compared with 10.5 per cent of deaths among those who were either taking a placebo or no nutritional."

sauceywolf, maybe this is what you were referencing:

"Despite its claims to be an independent review, the Cochrane study excluded 405 studies into vitamins because there were no deaths, and another 69 because they weren’t ‘randomised’ trials. As it is, the review looked only at studies that involved sick people, taking very high-dose synthetic vitamins, and which had participants dying. This does not replicate average use, and does not give the researchers the authority to claim that supplements shouldn’t be taken by healthy people." (http://www.wddty.com/033638003692754...lieves-it.html)


I haven't been able to locate the Cochrane review to read through it myself (if anyone can provide a link, i'd appreciate it), but from what I have read in the news I can't conclude that it is "sham" science.

All systematic reviews have exclusion criteria and the fact that this one did does not surprise me or cause me to believe that the results are faulty. Randomized controlled trials are one of the highest levels of evidence so the fact that they excluded lower levels of evidence (studies that were not randomized) also does not cause me alarm. The results of the Cochrane review are likely not generalizable to the population as a whole- and maybe that is the whole issue at hand. Is it possible that the media has portrayed the results of this study to mean something that they do not? Do the researchers themselves claim that the results are generalizable to healthy people?

I am definitely not claiming to be a research expert by any means. I'd love to hear from any nurse researchers out there that have read the Cochrane review and can explain the limitations of the study.

[beachmom]

When studies contradict what I have experienced in my life, I wonder about the studies.

I have always gotten sick easily, and when I take vitamins, I don't get sick as often.

Before I became a nurse, I did medical transcription and had carpel tunnel syndrome. When I took B-6, my carpel tunnel would go from moderate to mild. When I would forget my vitamins for a week or so, my CTS would get worse. I typed for 14 years, and I went on and off vitamins enough that I know it made a difference.

When I take my vitamins (B-6, E and Mg), my PMS symptoms are cut in half. Whenever I test this by not taking them, I have a really bad PMS month.

In my college nutrition class, we wrote what we ate for three days and determined whether we were getting the RDA of vits and minerals. I ate a better than average diet, but I was deficient in some of them.

Vitamins work for me, so I will continue to take them.

[RootedRedwood]

Originally Posted by beachmom

When studies contradict what I have experienced in my life, I wonder about the studies.

I have always gotten sick easily, and when I take vitamins, I don't get sick as often.

Before I became a nurse, I did medical transcription and had carpel tunnel syndrome. When I took B-6, my carpel tunnel would go from moderate to mild. When I would forget my vitamins for a week or so, my CTS would get worse. I typed for 14 years, and I went on and off vitamins enough that I know it made a difference.

When I take my vitamins (B-6, E and Mg), my PMS symptoms are cut in half. Whenever I test this by not taking them, I have a really bad PMS month.

In my college nutrition class, we wrote what we ate for three days and determined whether we were getting the RDA of vits and minerals. I ate a better than average diet, but I was deficient in some of them.

Vitamins work for me, so I will continue to take them.

I'm not sure how this study has "contradicted" what you have experienced in your life. The study was looking at mortality related to vitamin use, not whether or not vitamins "work". And again, as I stated in my previous post, the results are not likely generalizable to the public as a whole. So unless you are suffering from the same disease processes as the people in the studies, are within the same age bracket, are taking the same vitamins, and the same doses, etc, etc, etc...the results are likely not generalizable to you personally.

The problem with personal anecdotes about vitamins "working" is they leave a lot of other possible influences out of the equation. This is why studies are done the way they are- randomized, placebo-controlled, often double-blind. If you don't try to control the other possible variables, it is impossible to say that it is indeed one specific thing that is causing one specific effect. For all you know, you could get the same effect from taking sugar pills just as long as you still thought they were vitamins (aka the placebo effect).

Just my 2

[cardiacRN2006]

Originally Posted by beachmom

When I take my vitamins (B-6, E and Mg), my PMS symptoms are cut in half. Whenever I test this by not taking them, I have a really bad PMS month.

I take B6 everyday. The B6 is specifically to elongate a certain part of my cycle (luteal phase). The month I ran out of my B6 my phase shortened right back up (not good) almost immediately. I was shocked at how quickly this happened. And B6 is certainly better for me then say, Clomid (which caused me to temporarily go blind)

Originally Posted by RootedRedwood

If you don't try to control the other possible variables, it is impossible to say that it is indeed one specific thing that is causing one specific effect. For all you know, you could get the same effect from taking sugar pills just as long as you still thought they were vitamins (aka the placebo effect).

This study has the same problem by comparing death rates in a population that is taking vitamins due to chronic health problems. The fact that they had these chronic problems, such as heart disease, GI complaints, neuro stuff, etc results in similar problems as you've described:

It's impossible to say that one specific thing is causing that one simple effect (that's your quote, btw)...



Basically, you can't say the vitamins caused their deaths. There too much other stuff messing up the results (like, chronic conditions which cause death)

[Pocahontas98_21]

You mean it's packed with vitamin A not E. A polar bear's liver is packed with vitamin A about 9,000,000 IU

[RootedRedwood]

Originally Posted by cardiacRN2006

This study has the same problem by comparing death rates in a population that is taking vitamins due to chronic health problems. The fact that they had these chronic problems, such as heart disease, GI complaints, neuro stuff, etc results in similar problems as you've described:

It's impossible to say that one specific thing is causing that one simple effect (that's your quote, btw)...

Basically, you can't say the vitamins caused their deaths. There too much other stuff messing up the results (like, chronic conditions which cause death)

I am actually not really arguing for or against the researchers findings because I have yet to locate the studies in question and read them myself. Since it was a systematic review of many studies, some of the studies may have been well designed and others not so much. Again, if anyone can provide a link to the review- i'd love to read it.

Mostly, I have been surprised at how quickly many people dismissed the research without looking into it more closely and/or based on anecdotal evidence (btw, I don't believe B6 was not included in the study).

I'm assuming you have read the studies in question cardiacRN2006 since you seem to know a lot about all of the controls and inclusion/exclusion criteria each study used?