[Intanjir]

Choline is an essential nutrient. It happens to not be considered a vitamin but this appears to be simply a matter of completely arbitrary convention. The ontology of nutrition is not given much critical thought.
The simple fact is that if a person does not get enough choline in their diet then, at a minimum, their liver will not be as robust.
You do not derive calories from it.
It can be thought of as an important dietary source of methyl groups as much of it will get used toward methylation.
However it appears to be individually essential and cannot be completely substituted by other sources of methyl groups.
This is a bit unusual because we certainly have pathways in place that make much of our choline ourselves, but for whatever reason the body does not compensate to make enough of it when it is completely absent from the diet.

Choline is positive ion and so any formulation of it needs a negative ion to balance the charges. It would be physically impossible to isolate a large amount of a charged substance as you are well aware . They seem to use the bitartrate anion in most formulations. This certainly looks like one of those small organic acids that the body will use for energy, having nothing but hydroxyls and carboxyls. However this does not seem to be the case. It appears to be predominately metabolized by intestinal microbes, and what does get absorbed is probably mostly excreted intact in the urine. I would say this has negligible calories.
I base this off of the entry in the Human Metabolome Database which may be a useful resource for you:
http://www.hmdb.ca/metabolites/HMDB00956

[Doc.AElstein]

Hi Intanjir,
  Thankyou fort he reply. 
  The Genaral info is helpful to know, when I consider the usefulness of these ( “Choline Type” ) Suppliments.

As for the “Grouping” and Kcal contribution:
  So I think this is telling me that in this case ,   I could try to get at the bitartrate portion of  Cholinbitartrate  and then use the
Kcal  3 x organic acids
to get at the energy giving portion for this total Cholinbitartrate ( Choline giving me zero )
BUT
You are telling me that in this case the body is not able to utilize or “get at” the organic acids so that in case the Kcal from this would also be zero.

As for “grouping it somewhere, I think your “hydroxyls and carboxyls” should help me think of where to put it in  my “List of Things” !   

Thanks, this is the sort of info I can understand and is very helpful

Alan

[Intanjir]

I would place choline bitartrate with choline and I wouldn't pay much attention to the bitartrate moiety with its hydroxyls and carboxyls.
Choline might be grouped near its methyl donor metabolites betaine, dimethylglycine, and sarcosine.
From there it you might want to group it near other methylation system nutrients like folic acid and methionine.
Or you might want to group it near the various kinds of phospholipids, particularly phosphatidylcholine(lecithin).

The problem with trying to partition everything up into discrete related bits here is that this will be a poor reflection of the fairly interwoven topology here. I'd recommend just keeping any hierarchical categorization coarse and putting choline in some generic 'miscellaneous essential nutrients' group if that is compatible with your goals.

[Doc.AElstein]

Thanks once again Intanji,
That is very helpful in giving me some feel on what and "where
" these things are.

It is all still a big Jungle to me and when someone "in the know" gives a nice easy to understand explanation, and in particular relating itto where it stands in relation to other "things" it really helps bring in some clarity.

Thanks once again
Alan

[Intanjir]

Glad to be of help