Posted by Larry Hoover on March 25, 2007, at 11:42:58
In reply to Re: neighbourhood, posted by Squiggles on March 25, 2007, at 9:51:01
> Megadoses of salt - cute :-)
>
> I have not researched the effects of nutrients
> on psychiatry - i know that certain vitamin deficiences can cause mental illness. But there is a difference between a vitamin deficiency and a vitamin overdose - which in the case of lipophilic ones can be harmful and water-soluble, just something you void out without any benefit.Let's start with some basics, then.
Water soluble vitamins are not "just something you void out without any benefit". If that was true, they would not be vital to health at all. What you state is patently false.
For any substance to be excreted by the kidneys, in urine, it must first be found in the blood. During the time a concentration greater than zero exists for any such water soluble nutrient, all tissue compartments (including the organ, the kidney) have a similar opportunity to interact with the substance. If it's getting into urine, it has an opportunity, and presumably some success, at getting into other tissue compartments.
And why is toxicity such an issue? The RDA and its successor DRI both are defined in terms of clinical deficiency. Based on the mean intake level at which 50% of subjects demonstrate *overt* clinical symptoms of deficiency, they then go two standard deviations upwards, and hit the 95th percentile. In other words, the RDA/DRI is defined as the intake level at which 1 out of 40 *normal healthy* people shows *overt* clinical deficiency. I leave it to the reader to consider what is meant by normal or healthy.
Here is a graphical representation of those incidence curves: http://jn.nutrition.org/content/vol133/issue5/images/large/1563sf02.jpeg
The RDA is that point on Curve 2 at which the population (left scalar) is 5%.
The subject of this graphical representation, however, is what is here labelled AROI (Acceptable Range of Oral Intake). It is that region that lies between the 0th (that's zeroth) likelihood of subclinical deficiency, and the 0th likelihood of toxic effects. The RDA does not fall within this range. It lies far to the left.
What the AROI indicates is the range of *optimal* intake. Not a specific optimal intake, but the range of values it might have. For some nutrients, there is no toxicity known, so the AROI goes to infinity. Certainly, there are practical limits on that, but we're dealing with statistics here.
As an example, Squiggles, your lithium intake lies somewhere near the midpoint of curve 7. There are known toxic consequences (thyroid, kidney, etc.) to long-term exposure to lithium at those concentrations. You are well above the AROI, but that is for specific metabolic effects, which we like to call "treatment".
Compare the therapeutic index for lithium (i.e. 2), a mineral with no known normal application to human health, to the UL (Upper Limit) of dosage suggested by the same medical experts for vitamin E. The UL is theoretically the upper bound for AROI (i.e. the intersection of Curve 6 with the X-axis), yet for vitamin E, the "official" UL is 1/32 of the evidence-based upper intake level. Moreover, when toxic effects are shown, they are actually due to concommittant vitamin K deficiency!
I fail to see the rationale for treating these two substances differently, especially because vitamin E is truly essential to health. Why *are* nutrient side-effects treated differently than those caused by drugs?
> There is a PDR on foods and of course it is a huge field. Regarding lithium, there was a time when it was banned by the FDA because in its state then and dose, caused heart attacks as many salts will do.
Banned as a sodium chloride substitute. The context matters. Your generalization about salts is also questionable.
> So, the patent argument is part of the evil pharmaceutical company political armamentareum i think. Drug company profits are so huge, that one patentless drug is probably a tiny micromolecule in the bucket.
>
> SquigglesFollow the money, Squig.
Lar
poster:Larry Hoover
thread:744072
URL: http://www.dr-bob.org/babble/alter/20070320/msgs/744113.html