Hubby was on 9,000 a day then 6,000 and now 3,000 as directed by specialists, the under the tounge ones are better.
If these hadn't worked he would of had the jabs , however the way the HNS do the jabs they are to infrequent.
Buy the book "Could it be B12" by Sally Patholock it is really worth buying. You will probably have a light bulb moment.
Also it is highly likely it won't just be B12 that's the problem .....all the B bits, .Vit d , ferritin , gut absorption . Need healthy working guts to absorb thevits , bad guts can't absorb nutrients.
We are what we eat.
Can't remember if I have already posted this so apologise.
I am about to embark on a nutritional path , will report on it in 3/6 months if I feel it has worked.