Still suffering 2 months after loading dose

Hi Delilah, it is not uncommon for people not to respond to cyanocobalamin (CNB12), which is presumably the form that you have been given. CNB12 is a provitamin form of vitamin B12 and is not active. You need a bunch of enzymes to convert CNB12 to methyl and adenosyl forms of B12, which are the active forms. You are now stuck as your doctor will probably have no idea of this. Furthermore, because the test for B12 merely measures the fact that it is some form of B12, not which form, the doctor will most probably tell you that it can't be B12 as your levels are now high and so it must be something else. HE IS WRONG. You can try taking high dose riboflavin, which may help as the enzyme methionine synthase reductase needs riboflavin as FAD. Otherwise you need to wait until the CNB12 has flushed out and then start with mixed adenosyl and methyl b12. Have you worked out why your are deficient? Also do you have hypothyroidism, which can cause B12 deficiency  and which will mean that you can't convert riboflavin (vitamin B2) to FAD and FMN?

As I understand it some proportion of people ,a minorit,y cannot utilise cyanocobalamin. I understood perhaps incorrectly that it was then excreted. Some have a problem with methylation converting one form into the others. That will presumably show up in continuing high levels of homocysteine and methylmalonate. This will be elevated with B12 deficiency but should reduce with adequacy if the methylation can occur.  These are neurotoxic but it is not clear what proportion have this defect. It seems most don't. If you do the high continuing levels should show up on a blood test. In that case there are other factors as well as B12 involved eg most b vitamins, choline and betaine so wider based supplements may be required.

However as I understand it just stopping nerve damage is one thing, reversing it can take a long time. On some accounts the course is variable and it takes time to settle.

After the loading dose your levels can be very high - but that's a bit artificial.  I'm not sure how soon you can expect an improvement in the tingling.  Can anyone else help?

Hi Delilah, I think you will find the injections aren't quite "the magic bullet" doctors lead us to believe. Everyone else on here has explained it very well. My loading doses were back in March of this year, and I can honestly say I was expecting everything to be put right immediately. A lot depends on how long the B12 deficiency had been building up, your level of 78 is very low. By the time we are showing enough symptoms for it to be discovered, we will already have a degree of nerve damage. There is a very good book by Martyn Hooper, the founder of the Pernicious Anaemia Society, which explains a lot. It's called Pernicious Anaemia the Forgotten Disease. There are ways to help your body by adding vitamins and minerals to your diet. Often when some of these are low as well the B12 remains floating around your system, but doing nothing useful. I'm taking a good multivitamin each morning, plus a calcium & magnesium& vitamin D3 at night. Also some wheat germ added to my breakfast cereal. These combined with gentle exercise are beginning to help, so not so many sessions of numbness or pins & needles. I'm even waking in the mornings with less joint & muscle pain. It is taking a while to get to this state. above all, be kind to yourself, and rest when your body is telling you to! Hope it all improves for you soon. Best wishes Marion

hi delilah

just picked up your message. sorry to hear the b12 treatment doesn't seem to be kicking in as yet, partcularly in respect of the pins/needless & muscle weakness. has it helped in any other respect?

i'm not an expert on PA/b12 & i don't know you're specific diagnosis or/and history. however, the MRI would suggest that there's no permanent damage to the nervous system (sub-acute combined degeneration of the spinal cord) which is a great relief.

my feelings would be: since it takes years for b12 deficiency (PA) to develope, it's likely that it'll take some time for the body to repair any damage done. this won't happen over night. also, your body may need very high levels of b12 to negate the muscle etc. symptoms.

i've done a literature search on the internet & my library in respect of your question, but have not come up with anything useful. i'd suggest asking for a referral to a Haematologist if the symptoms don't subside. sorry i can't be of more help, but wish you all good luck in your endeavour.

Caitlin.