Gabapentin and Vitamin B12 Deficiency Risk

Medication Risk Listings in the 2024 NICE Guidelines

The 2024 NICE guideline on vitamin B12 deficiency lists colchicine, H₂‑receptor antagonists, metformin, phenobarbital, pregabalin, and primidone as medications that increase the risk of B12 deficiency, and explicitly does not include gabapentin among these risk factors. 1
Pregabalin, but not gabapentin, is identified by NICE as a drug associated with a heightened risk of vitamin B12 deficiency. 2

Both gabapentin and pregabalin are calcium‑channel α2‑δ subunit ligands used for neuropathic pain and epilepsy, yet only pregabalin has been linked to altered B12 status in the medical literature. 4
A comprehensive review of these agents concluded that, despite their similar mechanisms, there is no evidence that gabapentin affects vitamin B12 levels. 5

NICE advises that patients taking multiple B12‑risk medications should be regarded as having a cumulative risk for deficiency and may warrant monitoring. 3
Because symptoms of vitamin B12 deficiency (e.g., peripheral neuropathy, cognitive difficulties, balance problems) overlap with conditions for which gabapentin is prescribed, clinicians should assess such symptoms on clinical grounds rather than attributing them to gabapentin exposure. 1
Vitamin B12 testing should be performed when clinical signs suggest deficiency, independent of whether the patient is receiving gabapentin. 1