B12

[Milley2]

On a b12 injection how much is actually utilised ?

Does it all get used or only a tiny bit

Wondering ?

[palmier]

It depends on how much and what kind of b12. From what I've read, 30 % of a 1000 mcg hydroxycobalamin injection is retained (and used) but only around 15 % of a 1000 mcg cyanocobalamin injection. A higher percentage is retained from smaller injections, I think as much as 90 % of a 100 mcg hydroxycobalamin injection. There may be other variables as well that I'm not aware of.

[Milley2 in reply to palmier]

1000mg hydrox ?

[palmier in reply to Milley2]

No, micrograms.

[Milley2 in reply to palmier]

Confused now 😫

[Milley2 in reply to palmier]

Just wondered if it takes time to build up levels of b12

[fbirder]

It will vary a lot from one person to another.

It will vary a lot depending on what the serum levels of B12 are already. If your blood is already full of B12 then most of the injection will get eliminated in the urine.

B12 is eliminated in the urine. But the way the body does it is a bit strange. All of the B12 in the blood is filtered out when it passes through the renal corpuscle. This filtrate then passes into the tubule where the B12 is reabsorbed. What is left passes into the bladder as urine.

But this reabsorption has a limited capacity. If there is only a small amount of B12 in the filtrate then it all gets reabsorbed. But as the amount of B12 in the blood increases the limit for the amount that can be reabsorbed is reached. More and more of the B12 in the filtrate is passed in the urine.

So there is a maximum amount of B12 that can be in the blood. Any more will go out in the urine. This amount will vary from person to person, depending on how efficient their kidneys are.

[Milley2 in reply to fbirder]

My kidneys where all checked in hospital etc working or all seems ok

So I guess then it takes times for b12 to slowly level up itself? I’f on alternate day injectins ?

Hydrox

[Milley2 in reply to fbirder]

So if you frequently inject does it not help then if it seems it pasess out through urine

Or his first it every get increased to fir a healing level ?