My Experience

[GGourmet]

I wanted to share this, as this is my journey and I feel better than I have for years.

I am confirmed as B12 deficient and now take daily Methylcobalamin (2 per day, has been at 6 per day) and have injections every two months. I have to take daily supplements as I suffer from visual disturbance.

If serum B12 is below about 250 / 300 you might try asking your GP to test for functional B12. The test guidelines are in NHS Choices and costs the NHS around £5. Many GP's don't know about this test and don't even know that serum B12 is highly unreliable.

There are many causes of B12 deficiency and assuming that there is no issue if you are negative for autoimmune antibodies should not mean the end of the situation. There are easily around 8 conditions that can cause B12 deficiency plus more exotic causes.

I have gone through the full list and it now appears that mine is caused by SIBO but I am still waiting the tests but symptomology indicates it is SIBO. It has taken me 18 months to get to this point, battling all the way and conversations with the fantastic Martyn. I finally got things really moving when after being on B12 replacement for a while I suddenly became very ill and Crohns was suspected. This was actually an opportunity to get referred through BUPA hence why I now have a really good gastroenterologist.

[Gambit62 Administrator]

strictly speaking functional deficiency occurs where serum B12 levels are high - generally above normal range - so what you are talking about is testing that supplements serum B12 in identifying a B12 deficiency by measuring what is actually going on in the cell level, though the result is in the grey area - one of the 25% that serum B12 used as a single measure will miss just because of the limitations of serum B12 as a test.

[fbirder]

Testing negative for anti-IF antibodies doesn't tell you if you have PA or not.

PA is caused by AMGA (Autoimmune Metaplastic Gastric Atrophy). AMGA also results in low stomach acid (achlorhydria) which can cause SIBO (Small Intestine Bacterial Overgrowth). So it is quite likely that the B12 deficiency and the SIBO are both symptoms of AMGA.

Treating the achlorhydria and taking probiotics should rectify the SIBO but will have no effect on B12.

[GGourmet in reply to fbirder]

Thanks but Gastrin has shown stomach acid is normal. Condition has been linked to a very complicate history of antibiotics in the last 5 years or so and C Diff.