So I have symptoms of B12 deficiency, and to me they are devastating. How much, and what sort of, B12 do I need to take?
B12 is used in the body in huge quantities. It doesn't change, it's a Co-Enzyme or Catalyst or Transporter, so on the whole you don't use any up. But it seems to get deactivated and needs to be re-activated. We believe this process happens through entero-hepatic circulation, which means that inactivated B12 is grabbed by the liver and sent off through the bile ducts into the intestine, from where it's reabsorbed and somewhere along the line it gets reactivated.
This circulation system is extremely efficient. Lots of body biochemistry uses entero-hepatic circulation, and it may be for the same reason. For most people, all of the B12 that goes into the intestine gets reabsorbed. But some people aren't quite so efficient at reabsorbing.
Since everyone is different and people will have different rates of efficiency at reabsorbing, it's difficult to say from the symptoms whether you need tablets (to put more B12 into your gut so that more can be absorbed), or injections (to get it into the blood in the first place).
Since B12 is so safe, it's well worth trying tablets, in fact you can continue with tablets even whilst you are using injections.
The best tablets to use are probably methylcobalamin, methylcobalamin plus adenosylcobalamin, adenosylcobalamin, or a mix of B12, B6 and B9 (which were specially formulated to prevent dementia but probably also work on lots of other B12d symptoms). In simple terms, adenosylcobalamin gives you more energy and methylcobalamin helps your nerves, but your body can convert between the two really easily.
If the tablets really don't seem to be making enough difference - and do try both methylcobalamin and adenosylcobalamin (together if necessary) and check for other deficiencies such as Vitamin D) - then consider injections.
Cyanocobalamin is cheap - too cheap. We consider it too stable to be useful, and BNF (British National Formulary) seems to agree with us - don't use it. Look at the beginning of the name - what's that in with it?
Hydroxocobalamin is an excellent all-rounder. It converts readily into both methylcobalamin and adenosylcobalamin, it's easy to obtain and use, and we can provide 1mg/ml for injections of 0.5ml or 1ml regularly (usually once per month). Our hydroxocobalamin is made up with acetic acid to come to the right buffer pH.
Methylcobalamin is one of the pure forms that the body uses. ONLY get this if hydroxocobalamin doesn't work for you, and consider taking adenosylcobalamin tablets at the same time. The risk with methylcobalamin is that people who can't use hydroxocobalamin may also not be able to convert methylcobalamin to adenosylcobalamin, so you may still lack energy. We ONLY provide methylcobalamin once Dr C has reviewed your symptoms and you have already demonstrated that tablets and hydroxocobalamin don't work, and ONLY for people who need injections at least weekly or more frequently. It comes in 5mg/ml ampoules so you also need to be fairly expert at injecting to get 5 injections (1000mcg in each) out of each ampoule.
Although some companies say that they can provide adenosylcobalamin for injection, we haven't seen any benefit from this preparation so we don't have any.
Note that none of our products have preservative in them, so please use them sensibly.