***Always treat B12 deficiency first -***giving patients folic acid when they have a B12 deficiency can lead to subacute combined degeneration of the cord, (demyelination in the spinal cord with severe neurological complications).
B12 deficiency causes macrocytic Anaemia - DNA synthesis interference so produces large immature RBCs.
- Pernicious Anaemia (autoimmune condition - antibodies produced against intrinsic factor)
- Insufficient dietary B12 - particularly vegan diet
- Medications that reduce B12 absorption (e.g. PPIs, Metformin)
Neuropathy
- peripheral neuropathy
- Loss of vibration
- Loss of proprioception
- Visual changes
- Mood changes