NeuroTalk Support Groups - B 12 results, Huge improvement. too much?

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- - B 12 results, Huge improvement. too much? (https://www.neurotalk.org/vitamins-nutrients-herbs-and-supplements/10897-12-results-huge-improvement.html)

No need to feel alone. ;) My damage is long untreated SCD also.

The kidneys can have an effect on how you use B12.

150 mcg is nothing for someone who malabsorbs severely, and it sounds like you do. We who malabsorb severely need the 1000 mcg or more, because only about 1% gets through by default.

rose

O Rose,
Yes, I guess the 150mcgs would be sort of a stretch, huh?

If you'd be so kind,
please point me in a direction of the kidney relation to b12.

Dr's looking at my 9 amino acids that are low, (most listed as rare defieciencies (whew sp!)
ordered another test (urine) to see whats being "dumped".

He's testing my b1, b6, E, Seleinum, L-Carnitine, L-Acetyleblah blah blah....
among other, pyruvic, lactic and ammonia levels........

Put off my mri/brain and spinal till JUne, yippee.....the last spinal was a real bummer.......

I, as always, so appreciate all your help.

And, is a neuro the doc to pull this all together, a metobolic doc? what would that be called?

thanks
lah

Kidneys and cobalamin (B12):

The information goes back decades, although researchers still are trying to better understand the connection between kidneys and cobalamin. This is one of the issues about which mostly questions remain.

http://www.metabolismjournal.com/art...00661/abstract

This is very interesting. Maybe one of our more brilliant members can shed some light.

From: Megalin is essential for renal proximal tubule reabsorption and accumulation of transcobalamin-B12

Quote:

Megalin is important for normal uptake of filtered TC-B12 and accumulation of the vitamin. In megalin-deficient mice, increased urinary excretion of both TC (Fig. 2) and vitamin B12 (Table 1) was observed. Urinary B12 concentration was increased approximately fourfold despite significant lower serum B12 levels. As a result, urinary B12 clearance was increased ~28-fold in megalin-deficient mice. Furthermore, no vitamin B12 could be identified by immunocytochemistry in the proximal tubules from megalin-knockout mice, indicating defective cellular uptake of the vitamin (Fig. 3). Little or no TC was identified in urine from control littermates (Fig. 2), whereas cellular B12 uptake was evident in proximal tubules (Fig. 3). The defect in vitamin accumulation in megalin-deficient mice was further substantiated by the determination of vitamin B12 concentration in kidney cortical tissue from two megalin-knockout mice, showing a fourfold reduction compared with normal controls (Table 1).

From: http://ndt.oxfordjournals.org/cgi/co...ull/17/11/1867

Quote:

Cubilin
Cubilin is a 460-kDa peripheral membrane protein, previously referred to as gp280, and identical to the intrinsic factor-vitamin B12 receptor known from the small intestine. Its primary sequence, determined in rat [5], man [6] and canine [7], is conserved with an overall homology of 69% between rat and human cubilin and 83% between canine and human cubilin. Its structure consists of a 110 amino acid N-terminal stretch, followed by eight EGF and 27 CUB (Complement C1r/C1s, Uegf and Bone morphogenic protein-1 [8]) domains. Each CUB domain consists of 110 amino acids. The structure of CUB domains, which has been determined on spermadhesins [9] (a family of sperm proteins which consist of a single CUB domain), is characterized by two layers of five anti-parallel ß-sheets connected by ß-turns which include the least conserved regions and likely ligand-binding sites. Interestingly enough, a single spermadhesin can bind simultaneously two distinct ligands. The CUB domains can form dimers by piling up via the ß-sheets, in a manner that may favour the exposition of ß-turns to the surface. Therefore, the least conserved regions of the ß-turns will be preferentially exposed and available for interaction with ligands. This accumulation of CUB domains suggests that cubilin may interact with a variety of ligands.

Cubilin is a peripheral protein and its membrane association depends on the 110 amino acids at the N-terminus stretch [10] and may involve a putative amphipathic helix as well as palmitoylation. Biochemical and immuno-morphological data suggest that the internalization of cubilin is, at least in part, carried out by megalin [5,11].

Sure is some fascinating newer stuff to read! I'm not saying any of this is your problem, just providing some of the interesting literature that has been coming out as a result of more attention being paid to the kidney/B12 connection.

rose

Quote:

rose

The information here has been extremely helpful -- thanks to everyone.

Rose, on your website you say that "Hydroxocobalamin is generally preferred over cyanocobalamin" and that "Methylcobalamin has some advantages neither of the other types do."

I've had a lot of trouble with medications that have methyl compounds, so I'm particularly interested in the hydroxocobalamin. Can you say more about its advantages? And do you -- or anyone -- know how to find it in an oral form?

Also what would be the dosage of either of those alternatives that would be equivalent to 1000 mcg of cyanocobalamin?

I am continually amazed at how

uninformed doctors are.

They think that B12 is absorbed in the body orally like a "drug"?

250mcg is not likely to provide enough daily orally by passive absorption.
Usually only 1% is absorbed orally and that only it taken on an empty
stomach.

RDA means nothing when B12 is listed on a label.

The confusion also comes from the fact that IM injected B12 is 1000mcg/dose.
One cannot compare injectable and oral AT ALL... B12 is not like DRUGS...
which are mostly absorbed. If doctors would sharpen up and learn this,
much suffering could be ended! :confused:

mrsd,
My neuro doc poo-poo'ed the idea that the 150mcgs in the oral vitamin was helping,
that was my brainiac idea.

but while he was repeatedly exclaiming about the amount I've injected, it wasn't until I read that vitamin label, and saw what is considered--
(by who? RDA folks? who ever in the world they are--maybe they are the same folks to come up with the range for the b12 blood test 200-1000???!!)
-- a lot of b12..........

then again, at my urging my PCP tested my b12 levels, and at 220 - pronounced them "normal".....and that REALLY ticks off my neuro (cause 5months passed in the process)..........so yes, I guess the docs have a bit of homework to do.

please.....bear with me, so because of the complexity of the b12 molecule, and all it's applications, and all the possible points of breakdown in the process..........is THAT why it's not absorbed "like a drug". It's got to bind to other available molecules?

Rose,
thanks once again for the info.
I'm going to research the cublin & megalin.
Funny how I wrote to my kidney doc and asked if he's treated anyone with SCD, and if there was a connection to the kidney.

He had no idea, and nicely put me off, saying he would be available if the other docs wanted to chat.

I am lucky to have this place to look for help. As it's so frustrating to expect help from the usual channels.

lah

The 150 mcg dose would be plenty and then some for a person who malabsorbs only moderately. For instance, if you lack sufficient acid to break B12 out of food, but still produce plenty of intrinsic factor, you would absorb from even a much smaller dose.

But when one lacks intrinsic factor, only about 1% of the 1000 mcg is absorbed, and 1% of 150 mcg would probably not even be absorbed, and if it were it would be so little as to be less than a drop in the bucket.

B12 must jump though lots of hoops to get through. And once it gets through, if it is not methylcobalamin it needs to be converted to it.

I know of at least one brand of 1000 mcg oral hydroxocobalamin. "Pure" brand. I think it is available through "health care providers" and at very specialized supplement and herb shops.

Most of the docs only need to catch up on about 50 years worth of homework. Unfortunately, even those who care to refer to a medical reference will get the same old bad information. Editors are the ones who should be drummed out of the business.

Yes, hydroxocobalamin is better than cyanocobalamin, and methylcobalamin is better than either of those.

rose