Serum B12 reducing when not supplementing

[LynneG]

Hi, I wonder if reduction of B12 levels when not supplementing indicates that there is a B12 issue? I have posted before and my GP/Gp's state that I do not have a B12 issue despite symptoms because I have supplemented and raised levels.

In 2011 I started with significant burning mouth and re internet searches I managed to pursuade my GP to test B12 levels. Result 191 which at that time in the UK was the v bottom of the normal range. But I was told over the phone B12 is perfectly normal. As I became more knowledgeable I started to supplement but on and off as always was the niggle that B12 level was perfectly fine as told. My burning mouth would go when supplemented and then I became blaze and stop.

In 2017 I was hit with burning mouth and neurological problems. With advice from this site I started supplementing with 5000mcg of B12 - at my annual blood tests (RA) my levels raised to 1700. My homocysteine had come down to 8. I carried on supplementing for many months so my B12 level would have been much higher. I decided to stop supplementing for 6 months to see what happened. Unfortunately as blood taken at the request of a consultant I could not get the result until the next app and that was delayed. My B12 level after 6 months of not supplementing in Oct18 had fallen to 795 , about 3 months later it was 675 and a few wks later with my GP annual tests I managed to get B12 again without the GP noticing that I had, had taken recently and it had fallen to below 600. I did take a few 5000 mcg too once blood test taken in Oct but stopped when the next blood test approaching. My question is should my levels have fallen so quickly if I didn't need B12 supplementation? I see that if like most folks that I didn't supplement then my levels would soon be back at 191 before I knew it. Surely this should not be the case and not normal. Especially as I was eating red meat , A duck egg every day and liver once per week. My Homocysteine has risen from 8 to nearly 10 also during that period. Anyone have any thoughts please before I point this out to my GP. Thank you

[Gambit62 Administrator]

Difficult to get a clear picture. If you raise B12 levels with supplementation, once you stop supplementing you would naturally expect levels to fall, regardless of whether you have an absorption problem or not - until they get to the levels that are right for you - at which point (assuming you don't have an absorption problem) your body would start using the reserves in your liver to maintain levels. So, falling to 600 is difficult to interpret.

The real question has to be how are you feeling. If the supplementation helped then I'd go back to it. If it didn't then may be that B12 isn't actually part of the problem.

[LynneG in reply to Gambit62]

Thanks Gambit. So you would expect levels to stabilise at a point my body requires. A large concern of mine is the rising of Homocysteine during the fall of B12 levels. It is well documented that a healthy homocysteine level is 6-7. I also worried that the B12 serum level would keep falling. So it is good to know that it should stabilise. I just wonder how a serum level ever becomes so low as 191 or less on a normal diet. Dr Chandy (B12 Charity told me that for my level to have been as low as 191 that damage would have been occurring for the previous 10 years) With reference to symptoms they are about the same as were never eliminated, but then I did not expect them to be affected until replete with B12 / above a level of 2000 before damage will start to heal. However I have severe vertigo now and so feel B12 falling could be the cause of this

[fbirder in reply to LynneG]

Your B12 does not need to be above 2000 before any damage starts getting repaired.

As Gambit62 says, your levels will drop once you stop taking supplements. Exactly what level they stabilise at will depend on several factors.

People without any absorption problem (and you appear not to have one) will find levels drop more slowly, and stabilise higher, than those with such a problem - because B12 excreted in the bile can be reabsorbed in the ileum.

People's kidney and liver functions are quite variable. That can change the rate at which B12 is eliminated and how much can be stored.

Your diet will play a big part. If you eat a lot of B12 then your levels will drop more slowly, and stabilise higher, because you keep them topped up with food.

Despite what some doctors tell you, a level of 191 doesn't mean that you will have been suffering damage for 10 years. Indeed, 191 pmol/L is the normal level for a lot of people who are totally free of any symptoms of a B12 deficiency.

[LynneG in reply to fbirder]

Thanks fbirder. Great info, thanks for passing on your insight and understanding of process. I think I will re start taking 5000mcg re symptoms and also because I am not happy with such a high homocysteine level which has risen when my B12 level has fallen and had come down previously as my B12 rose. There should not be any worries anyway if it is not harmful to have a high B12 level.

I am sure that I do not have any absorption problems, my concern is whether the B12 is being transported into cells efficiently and a high +2000 seems the best course of action to take according to people on here in a similar situation.

I think the doctor was referring to the fact that damage occurs with a low B12 but that you don't recognise until enough damage has happened over time/ many years and then when enough damage has happened, you get symptoms which takes you off to the GP and blood tests. My grandma was discovered to have PA too late when she developed Parkinsons and as a result my father was tested for deficiency and had B12 injections from the age of 50 for 35 years until his death caused by anaemia. So having started with symptoms, B12 levels and homocysteine levels are obviously not something I take lightly and prefer to be proactive now that I am gaining more knowledge which I appreciate this site greatly for

[Gambit62 Administrator in reply to LynneG]

LynneG, as above in my first response what is important is whether you are feeling symptoms of B12 deficiency and if your symptoms improved with a shot and then the symptoms came back. If your homocysteine starts to rise above normal range even when your folate levels are good and your B12 levels are high then that would imply that your cells don't have enough B12 even though your serum B12 levels are high (functional B12 deficiency).