Meta Information
ID:vitamin-b12
Name:Vitamin B12 (Cobalamin)
Schema Version:2.4_uniform_evidence_2026_06_18
Created
2026-07-02T07:04:56Z
Model
phase-b-newfiles-claude-opus-4.8
Interactions
Target id:
/intervention/metformin
Target name:
Metformin
Severity:
moderate
Interaction type:
diminishing
Nature:
relative
Temporal spacing:
Hours before target:
0
Hours after target:
0
Description:
Long-term metformin reduces vitamin B12 absorption and can cause deficiency over time.
Actionable advice:
If on long-term metformin, check B12 periodically and supplement if low.
Validation status:
validated_via_class_inference
Evidence tier:
tier_c
Evidence basis:
class_inference_summary
Evidence anchors:
Source url:
Established mechanism / class pharmacology (no single primary source quoted)
Exact phrase from label:
Metformin impairs ileal B12 absorption; well-documented depletion. Established mechanism.
Label source:
Class inference
Action type:
monitor
Target id:
/class/proton-pump-inhibitors
Target name:
Acid suppressors (PPIs, H2 blockers)
Severity:
minor
Interaction type:
diminishing
Nature:
relative
Temporal spacing:
Hours before target:
0
Hours after target:
0
Description:
Long-term acid suppression reduces release and absorption of food-bound B12.
Actionable advice:
With prolonged acid-suppressant use, consider periodic B12 monitoring.
Validation status:
validated_via_class_inference
Evidence tier:
tier_c
Evidence basis:
class_inference_summary
Evidence anchors:
Source url:
Established mechanism / class pharmacology (no single primary source quoted)
Exact phrase from label:
Gastric acid frees food-bound B12; chronic acid suppression lowers B12 over time. Established.
Label source:
Class inference
Action type:
monitor