Are b12 levels always high when a patient is on injections or not?

[Roo32]

This article below has comments saying that b12 blood levels are always above the upper limit when a patient is receiving injections, and other comments say that only with weekly injections did they finally get their level into the range from being too low. Can anyone explain which is true or why both may be?

nursinginpractice.com/perni...

[Gambit62 Administrator]

The article doesn't actually say anything about levels of B12 in blood post injections - the comments do.

Serum B12 and active B12 are difficult tests to interpret on their own because of the way the body uses and regulates B12 levels in blood. There is a huge variation in the normal level of B12 for individuals and people tend to use stores from the liver to maintain B12 levels at the point that is right to them as an individual. This means that there is a logical problem with assuming that a given individual is okay because their blood levels are in the normal range.

If you have an absorption problem though the mechanism that allows you to regulate your B12 levels is broken/inefficient as it relies upon the same mechanism as you use for absorbing B12 (stores of B12 released in bile to be reabsorbed into the blood through the ileum), so you see falls in levels of serum/active B12.

so, if you need levels at the top of the range but your B12 is in the lower part of the range because an absorption problem means your levels are falling then just looking at serum B12 or active B12 is going to be misleading.

An injection of B12 puts huge amounts of B12 in to your blood - which is problem number 2 with using serum and active B12 post injections.

Another problem is the huge variation in the time it takes for B12 to be removed from the blood and pass out in the urine - although the average is 1 month for cyano and 2months for hydroxo in some people hydroxo is removed quicker than cyano and in others the time taken can be years rather than months.

The fourth problem is that raising serum B12 can also lead to functional B12 deficiency - no body is quite sure what mechanism is involved but the net result is that people something seems to make the process that transports B12 from blood to cells - meaning that many people need higher levels of serum B12 to ensure that enough gets through to cells post loading shots.

This reaction is common enough for functional B12 deficiency to be recognised as a symptom of a number of conditions that can cause serum B12 levels to rise (eg liver and kidney problems) - where patients report all the symptoms of B12 deficiency although their B12 levels are actually much higher than they should be.

[fbirder]

I cannot find a comment where somebody said that their B12 levels drop significantly one week after having an injection. And if I did, I would not believe it.

What I would believe is if somebody said that their symptoms returned if they didn't get weekly injections. That just goes to show that, for some (most??) people, B12 levels are a lousy indicator as to what frequency of injection is needed.

[Roo32 in reply to fbirder]

Yes, I meant there are comments (at least 2) which seem to say that until they were injected more frequently their blood levels still tested low even after several injections. I didn’t think this ever happened unless a person has say, an internal bleed.

[fbirder in reply to Roo32]

No, I still can't find them. Can you post direct quotes so I can do a search?

[Roo32 in reply to fbirder]

Sure-

"J Walker's comments do not apply to my case or that of my father. With conventional B12 treatment we both stay on the very low side of the 'normal' ref range used by the labs. My father's serum B12 was still under the labs ref range of 'normal' after three months of conventional loading. My serum B12 just dropped year after year and could be considered under the ref range of some labs. I know different labs use different machines but have experimented with having two blood tests in two different counties (same day three hours appart) to find the serum B12 level measued at each lab to be the same but the ref range for normal rather different." - Mrs M Dafforn, UK

...it was possible/necessary to have more frequent injections. The nurse said that 3 monthly is enough and that it was just a psychological need that people felt to have more frequent injections. Obviously I went away thinking I was a wingeing hypochondriac so suffered in silence. Another 6 months down the line and I queried my annual blood test results with the

nurse and found out that I had been below the lower limit for the last 2 years - no one at the practice had picked up on it.

This then prompted a rather panicky referral to the consultant again (at extra cost to me) who simply advised I go on monthly injections. This experience simply re-inforces my view that the reference ranges are fundamentally flawed." - Mark Tweedale, Lancs

"I agree with the claims made by Mr Hooper. Its been 8 years now since I was diagnosed with PA, I spent 6 years on "conventional" three monthly hydroxocobalamin jabs and lost one month out of three, and developed metrological problems. I just was a washout, unable to concentrate and living in a demented fog; time meant nothing and my family suffered as just driving down the road would leave me exhausted and dizzy to the extent I had to more or less stop on the road if I had gone round a round about. Having relatives abroad I found my own B12 supplies and learned to self-jab, it's taken two years but I am now just normal, with far more frequent B12 (cyanocobalamin) jabs, no regular ups or downs and able to do what any other my age can. My blood tests are only now "normal", it's taken 8 years, I feel it's not acceptable that others in the same boat are not able to get back their quality of life by these stringent (possibly out of date) BNF guidelines. Treatment guidelines in other EU countries recommend more frequent B12 jabs, maintenance once every two months being the general "norm" for hydroxocobalamin, even the manufacturer recommends one every two months as a general guide, so why are UK PA patients expected to cope with less frequent B12 jabs than other EU PA patients?" - M Dafforn

[pejka62]

My B12 level was 200 when my doctor starting weekly shots--after one month the reading went to 1500 and the doctor said don't worry about it, that we have to overdrive the reading for a period of time until the nerve damage I had in my legs could repair itself as good as it could with the damage I had. After 52 shots I stopped taking them and just take the pill every day now and my reading is about 440--perfect.

I got about 65% of the nerves that would damaged in my legs back and that is probably all I will get because the others were dead and could not be saved. I'm much better off than I was 2 years ago with about 30% of the leg pain I had before. If I wouldn't have found this doctor and fired my other one. I believe I would be in a wheel chair today.

[Roo32 in reply to pejka62]

That’s really interesting. So you had weekly shots for a year until no further improvement was noted in your leg and then went on to supplements? What was the reason for your low b12 levels of you don’t mind me asking (and equally if you know)?

[Lurcher-lady in reply to pejka62]

Wish my doctor was like yours

[pejka62]

Don't know exactly why I was so low on B12. I have a few ideas--like my wife does not eat meat and so I ate a lot of meatless meals for the last 20 years. Also I had 10 inches of my colon taken out about 10 years ago which would lessen the abortion of B12 and the fact that I am 79 years old because you only get about half of the B12 from the same food after about 50 to 60 years old. After two operations--one on my back and knee that the doctors thought was give me the pain and they did nothing, I insisted on every blood test possible to see if something was wrong and that's when we found the B12 was so lowI am much better now then I was 2-3 years ago but still have considerable pain in my legs and can't walk very far. I am very active for my age and still put on roofs and play golf two times a week. I also have been the club champ at several different courses and still shoot close to even par but it's been a journey with this B12 thing. I may have had this problem for several years before I found out what it was. Never knew much or anything about B12 all my life but I know some things now. LIFE IS GOOD. Jim