[ExI] Once again: Some vitamins don't help in large doses

[dan_ust at yahoo.com]

--- On Mon, 5/18/09, Stefano Vaj <stefano.vaj at gmail.com> wrote:
> On Mon, May 18, 2009 at 4:10 PM, Dan
> <dan_ust at yahoo.com> wrote:
>> Let me make an analogy.  It's like you telling me you
>> ate food and got a stomach ache tones and me pointing out
>> lots of people eat food and don't get stomach aches.  Well,
>> what food did you eat?  What food did they eat?  Is there
>> any evidence the specific food you ate gave you a stomach
>> ache?
> 
> Yes.

I was only using this analogy in regard to Michael LaTorra's claim about kidney stones.  Specifically, he tells us:  "I [LaTorra] say this as someone who took supplements for over 20 years. All I [LaTorra] got was kidney stones."  I didn't mean for it [the analogy] to be applied beyond that.

> In any event, as far as aggressive supplementation is
> concerned, I
> would mantain that as long as it is reasonably believed to
> be safe,
> and one suspects on anedoctical or personal empirical
> evidence that it
> may do something for him or her (including as a placebo:
> who cares?)
> it is certainly no worse than tea or mineral water,
> something which
> also cost dollars, and which nobody thinks of objecting
> to.

I think it depends on your goals and how you assess the risks and the data.  I think there's some evidence that high doses of some supplements or supplement combinations are beneficial.  There's also some mixed results on some supplements.  And Michael is right to be worried about industry shills and bad research -- after all, if someone wants to sell you something, there's a definite incentive to downplay risks and focus only on potential benefits -- but the point of my analogy was only to respond to his claim about kidney stones.  We (and maybe he) don't (doesn't) really know why he got kidney stones and, more importantly, what this tells any one of us what we should do about supplementation -- other than a general view of being skeptical and researching before popping pills.
 
> Then, even if ten thousand double-blind tests were to tell
> me that
> ginseng or L-carnitine or melatonin do nothing I would be
> really hard
> pressed to believe it any more than similar tests telling
> me that heroin or coffee do nothing.

Well, to be sure, if there were "ten thousand double-blind tests," that'd be a lot to go on -- and I'd be surprised if such studies didn't give some answers to many of the questions reasonable, unbiased folks have on taking supplements.  Of course, a lot would depend on how the studies were done --what doses were used (it's possible really low doses show no results because there's too little of the substance to do much; it's also possible that dose-response varies -- as in there's a beneficial dose range and above or below that there is no benefit or even there is harm), what forms of the supplement were taken (for instance, vitamin E is actually 8 compounds and one shouldn't be surprised if a study done with one of these does NOT match results for another), the specifics of the study group (results from a study of healthy teenage Swedish boys might not apply to sedentary postmenapausal Chilean women), the length of the study, etc. -- assuming, of
 course, the studies were well designed and there was no cooking data.

Sadly, a lot of studies of supplements fail to be good studies -- often because they're short duration, the substances under study is a variant that might not apply to others (as in the vitamin E case: many studies are of alpha-tocopherol -- and not of other forms of E alone or together), take a specific population (as seems the case in the article LaTorra cites* where the study supposedly focused on "young men"), or don't have a good control group (such as when there's a five year study of nurses taking a certain supplement**).


Regards,

Dan

*  http://www.nytimes.com/2009/05/12/health/research/12exer.html?em

**  I don't recall the specific study, but the point is that while such a study might be suggestive, it's much harder if not impossible to isolate a cause and effect relationship.  For example, did the nurses also get a lot more exercise and perhaps eat healthier?  Without a better study design, we can't tell.  It might even be that the supplement in question did harm, but the nurses did other things that overcame this.  If other people then start taking the supplement, they might not get the same effect and might even be harmed.