Hi, I have just moved to a new B12 practice, lovely GP but they are a bit wobbly on frequncy of b12.
Im taking methy foliate, B2, iron, magnesium, D and potassium daily plus injecting hydroxycobalamine 1mg every week. I feek OK on that. perhaps not perfect but no neurologicalsymptoms, I can work and I can run 20+ km a week.
The GP was worried that my serum B12 was at above 6000 ng/L ( way off the normal scale really where 800 is the top of the normal band) and ordered an 'active' B12 test (trans cobalamine) which gave a result of 128 pm/L. which is very 'normal'.
Does anyone have experience of interpreting these tests, my assumption would be that this implies I need a massive loading of injected hydroxycobalamine to reach a normal level of active serum B12. Its clearly more complicated, as cerum B12 is not doing you good untilits in cells, but as a first approximation that seems plausible.
Any thoughts or experience?
PS I'm buying B12 from Germany and self-injecting so GP is currently providing tests and advice not B12
Written by
oilbeetle
To view profiles and participate in discussions please or .
"The GP was worried that my serum B12 was at above 6000 ng/L ( way off the normal scale really where 800 is the top of the normal band) and ordered an 'active' B12 test (trans cobalamine) which gave a result of 128 pm/L. which is very 'normal'."
A few thoughts
It's my impression from reading many threads here that there are lots of doctors and health professionals with wrong ideas about B12 deficiency.
Stitchting B12 Tekort - Dutch B12 website with English articles
Treatment with high dose vitamin B12 been shown to be safe for more than 50 years
Search for "Wolffenbuttel B12 deficiency" to find other articles he's written, including one for Mayo Clinic in US and one for BMJ (British Medical Journal).
His most recent article, an overview of B12 deficiency treatment/diagnosis, was published in 2024.
Search for "2024 Wolffenbuttel B12 overview" to find it.
In my personal opinion he's one of the few doctors who understands B12 deficiency.
4) B12d.org has some interesting online talks about B12 deficiency
I left some detailed replies in threads below that might be of interest eg links for those in UK struggling to get adequate treatment, suggestions of UK health documents to read and some general info about PA and B12 deficiency.
Thank you, that was an incredibly detailed and useful reply. I have a PhD in chemistry, but I'm out of my depth on B12, its so complex [no pun intended].
I think I'm going to have to agree to disagree with my GP. She seems smart and caring, but is trying to follow guidance from NICE and from specialist haematologists which is plain wrong.
I have ordered this and I'm starting to think pernicious anaemia is not a single condition with a single optimum treatment, it seems like a range of conditions where B12 adsoption, transport and metabolism are involved
My active B12 is 147pmol/L and my serum B12 is 2,000. I am waiting to receive treatment and am feeling pretty rough, with lots of neuro symptoms. Fortunately, I have B12 ampoules on the way.
The UK parameters state that anything below 70pmol/L active B12 is sub-optimal. Whoever wrote that is welcome to change shoes with me for a week.
My understanding is that active B12 (plasma) is still a new test to most doctors and interpretation of results when it comes to people with low B12/PA is definitely still up in the air.
My active B12 was 56pmol/l (and serum was 172pmol/l) both of which my initial GP said was “low but ok”. But since it was the only thing that seemed out of whack on my tests, she chose to treat it with injections. Thank goodness.
It’d be nice if they found something similar to the Schillings test
It is very normal when you are injecting B12 to have B12 test results out of range. Don't worry- your body will excrete any that it does not need. Just carry on injecting!
Content on HealthUnlocked does not replace the relationship between you and doctors or other healthcare professionals nor the advice you receive from them.
Never delay seeking advice or dialling emergency services because of something that you have read on HealthUnlocked.
IFA negative, Low Active B12 - advice please. 
Active B12 test - again
Active B12 Test
Result of 'active B12 test'
