There are plenty of resources to help you learn more about vitamin B12 deficiency and to support you in your quest for better healthcare.
Organisations
Pernicious Anaemia Society Twitter: https://twitter.com/PASOC
B12 Deficiency Support Group Twitter: https://twitter.com/b12d
Books
Books are always invaluable educational resources. The ones below are particularly excellent.
Could it be B12?: An Epidemic of Misdiagnoses – by Sally M. Pacholok
Living with Pernicious Anaemia and Vitamin B12 Deficiency – by Martyn Hooper
Pernicious Anaemia: the Forgotten Disease: The Causes and Consequences of Vitamin B12 Deficiency – by Martyn Hooper
The Homocysteine Solution – by Patrick Holford
The Heart Revolution – by Dr. Kilmer McNully
Supplements
Thorne Research – oral vitamin supplements. In our opinion these are the most bioavailable, with the most rigorous scientific research backing up their formulations. They are available in the UK.