Phred wrote on Sat, 16 Jan 2010 15:48:00 GMT:

> In article >,
> in a previous thread which I have lost, hence this new one
> "cybercat" > quoted:
>>>>> Mark Thorson > wrote:
>>>>>> Andy wrote:
>>>>>>> The most important point that folks constantly fail to
>>>>>>> realize
> is
>>>>>>> that synthetic vitamins are useless.
>>>>>
>>>>>> How does your body know whether a molecule of vitamin C
>>>>>> was made by a plant or in a factory? They both have
>>>>>> all of the same atoms in all of the same place.

> I don't know about vitamins as such, but IICR organic
> chemistry from 50 years ago, compounds that exist in two
> optically active forms (Dextro and Levo) are often (always?)
> biased to one form in natural biological systems but are made
> in equal amounts in lab processes unless such are designed to
> produce the separate forms.

> The two mirror forms of racemic compounds are known as
> enantiomers and have identical properties except for the
> rotation of plane polarised light. However, the racemate [the
> 1:1 mixture] often has different properties to the pure
> enantiomers (different melting points and solubilities are
> very common). In the present context it's worth noting that
> pharmaceuticals may be available as a racemate or as the pure
> enantiomer, which might have different potencies.
> <http://en.wikipedia.org/wiki/Racemic_mixture>

> Enantiomers of each other often show different chemical
> reactions with other substances that are also enantiomers.
> Since many molecules in the body of living beings are
> enantiomers themselves, there is often a marked difference in
> the effects of two enantiomers on living beings. In drugs, for
> example, the working substance is often one of two
> enantiomers, while the other one is responsible for adverse
> effects. <http://en.wikipedia.org/wiki/Enantiomer>

> It worth noting that virtually all active forms of amino acids
> are of the L-form (d-serine being a notable exception) and
> most biologically relevant sugars are of the D-form.
> Typically, the alternative form is inactive and sometimes even
> toxic to living things.
> <http://en.wikipedia.org/wiki/Homochirality>

> [All of which goes to show that my memory has not yet
> completely failed; and suggests that Andy may have had a good
> point when talking about synthetic vitamins.]

All that is true and interesting but we should not get distracted from
the fact that truly generic drugs possess the same handedness as the
originals. The only real difference can be in the formulation of pills
which may dissolve at different rates.

I don't have any particular liking for multivitamins and have doubts
about their efficacy and even what they are supposed to achieve. The
same applies to plant extracts like Echinacea whose content of the named
active principle can vary over a vast range.


--

James Silverton
Potomac, Maryland

Email, with obvious alterations: not.jim.silverton.at.verizon.not