Gabapentin and Vitamin B12 Levels
No, gabapentin does not lower vitamin B12 levels. The most recent and authoritative 2024 NICE guidelines on vitamin B12 deficiency specifically identify pregabalin—not gabapentin—as a medication associated with B12 deficiency risk 1.
Evidence from Guidelines
The 2024 NICE guidelines explicitly list medications that are risk factors for vitamin B12 deficiency, including 1:
- Colchicine
- H2 receptor antagonists
- Metformin
- Phenobarbital
- Pregabalin (not gabapentin)
- Primidone
Gabapentin is notably absent from this list, despite pregabalin being included. This distinction is clinically important because gabapentin and pregabalin are both calcium channel α2-δ ligands with similar mechanisms of action, yet only pregabalin appears to affect B12 status 2, 3.
Supporting Research Evidence
A 2011 prospective study of 2,730 antiepileptic drug-treated patients found that gabapentin treatment was associated with lower folate levels, but the study did not demonstrate an association between gabapentin and reduced vitamin B12 levels 4. Treatment with phenobarbital, pregabalin, primidone, or topiramate was associated with lower B12 levels, but gabapentin was not among these medications 4.
Clinical Implications
While gabapentin does not appear to lower B12 levels, clinicians should be aware that 1:
- Patients on multiple medications may have cumulative risk factors for B12 deficiency
- Symptoms of B12 deficiency (peripheral neuropathy, cognitive difficulties, balance issues) can overlap with conditions for which gabapentin is prescribed
- If a patient on gabapentin develops symptoms suggestive of B12 deficiency, testing should be performed based on clinical presentation rather than medication exposure alone
Common Pitfall to Avoid
Do not confuse gabapentin with pregabalin regarding B12 deficiency risk. Despite their pharmacological similarities as calcium channel α2-δ ligands used for neuropathic pain and epilepsy 2, 3, only pregabalin is recognized in current guidelines as a risk factor for vitamin B12 deficiency 1.