priors.science/reviews/vitamin-b12

Vitamin B12

The current evidence on 9 claims, ordered from most established to most contested. Each score is the panel’s evidence certainty — how firmly the literature supports the claim as stated.

9claims tracked
150primary papers reviewed
5 Jul 2026latest evidence review
Weeklyre-scored against new papers
2 Established · 3 Likely · 2 Uncertain · 2 Doubtful  |  four-reviewer panel · PICO Framework
SignalClaimStandingEvidence certaintyCorpus
StableVitamin B12 lowers homocysteineHomocysteine CardiovascularEstablished90%20
StableVegans risk vitamin B12 deficiencyDeficiency And StatusEstablished88%20
StableMetformin lowers vitamin B12Deficiency And StatusLikely83%20
StableVitamin B12 corrects deficiency neuropathyNeurocognitionLikely82%20
StableOral vitamin B12 matches injectionDeficiency And StatusLikely68%20
StableB vitamins reduce strokeHomocysteine CardiovascularUncertain56%20
StableMaternal vitamin B12 aids neurodevelopmentNeurocognitionUncertain46%20
StableVitamin B12 halts cognitive declineNeurocognitionDoubtful30%20
StableB vitamins cut cardiac eventsHomocysteine CardiovascularDoubtful18%20
Standing — what the evidence certainty means
Established≥ 85%Strong, consistent evidence. Unlikely to change.
Likely65–84%Well supported, with some gaps or indirect evidence.
Uncertain40–64%Mixed or limited evidence. Genuinely open.
Doubtful15–39%Little support; the weight of evidence leans against it.
Refuted< 15%The evidence contradicts it — confidently false as stated.
Recent signal
strengthenedNew evidence raised the certainty since the last review.
weakenedNew evidence lowered the certainty since the last review.
newA claim added to the review recently.
StableNo recent change to the standing.
Standing, evidence certainty and corpus are always shown. The study behind each move, why it moved, and the sceptic’s challenge are delivered to subscribers.
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