Vitamin B12 for Cognitive Function
Water-soluble vitamin required for red blood cell formation, myelin synthesis, and DNA production; deficiency, common in older adults and vegans, causes fatigue and neurological symptoms that supplementation corrects.
Vitamin B12 for Cognitive Function
2 of 3 results reported a benefit, from 2 published studies.
2 studies, including a review of trials · the chart counts everything measured
- 2 reported a benefit
- 1 no clear benefit
Colour keyReported a benefitNo clear benefitUnclearPossible harmAmber is for highlights, such as where the most research is. It never means a result was good.
- Overall thinking skillsNo clear benefit foundmeasurement not reportedVitamin B12 supplementation showed no significant benefit for cognitive function compared with placebo in people with dementia and low B12.1 review of trials2003 study ↗
- Attention and calculationReported a benefitsee exact figuresVitamin B12 improved attention and calculation vs control in 115 patients over six months.1 randomised trial2023 study ↗
- Visual-spatial abilityReported a benefitsee exact figuresVitamin B12 improved visual-constructional ability vs control in 115 patients over six months.1 randomised trial2023 study ↗
These are the figures the studies reported, not a prediction for any one person. Where several studies measured the same thing in the same unit, we show a simple average and say so. Every result is listed below.
See every resultThe connection
Memory, mental clarity and overall brain health.
Also known as: Methylcobalamin, Cyanocobalamin
Vitamin B12 × Cognitive Function: at a glance
Every published result for this pair, extracted and audited.
These charts count reported findings from published studies, grouped by reported benefit and study design. Study design is not a certainty grade.
Vitamin B12 / Cognitive Function: reported findings; one study may contribute several findings.
What the evidence shows
What this means: Counts describe research quantity, not treatment effectiveness or certainty.
| Category | Findings (count) |
|---|---|
| No benefit | 1 |
| Benefit | 2 |
Study designs behind these findings
What this means: Counts describe research quantity, not treatment effectiveness or certainty.
| Category | Findings (count) |
|---|---|
| Meta-analysis | 1 |
| Randomised trial | 2 |
- Studies
- 2
| Study | Outcome | Reported result | Uncertainty (as reported) | Study duration |
|---|---|---|---|---|
| Vitamin B12 for cognition. (PMID 12918012) | Cognitive function in people with dementia and low serum B12 | Not reported | Not reported | Not reported |
| Vitamin B12 supplementation improves cognitive function in middle aged and elderly patients with cognitive impairment. (PMID 37334792) | attention and calculation | Not reported | p < 0.01 | six months |
| Vitamin B12 supplementation improves cognitive function in middle aged and elderly patients with cognitive impairment. (PMID 37334792) | visual-constructional ability | Not reported | p < 0.05 | six months |
Study results, as reported by the publications
Every measured outcome, one row per finding - numbers exactly as reported. Units are preserved where supplied; missing units are not inferred.
| Study and type | Reported sample and duration | Outcome measured | Reported result | What studies found |
|---|---|---|---|---|
| PMID 12918012 2003 Meta-analysis | Sample (as reported): Not reportedDuration: Not reported | Cognitive function in people with dementia and low serum B12 | Not reported | No benefit |
| PMID 37334792 2023 Randomised trial | Sample (as reported): 115Duration: six months | attention and calculation | Not reported (p < 0.01) | Benefit |
| PMID 37334792 2023 Randomised trial | Sample (as reported): 115Duration: six months | visual-constructional ability | Not reported (p < 0.05) | Benefit |
Vitamin B12 × Cognitive Function: the evidence base
Hand-selected PubMed studies, linked to the originals.
Ordered by strength of evidence, then result direction.
01Ginkgo biloba for cognitive impairment and dementiaWieland LS, et al. · The Cochrane database of systematic reviews · 2026PMID 41641880 ↗02Differences in Ferritin, Vitamin D, and Vitamin B12 Between Fibromyalgia Patients and Healthy Individuals: A Systematic Review and Meta-AnalysisIsmail O, et al. · Musculoskeletal care · 2025PMID 39832803 ↗03Effects of acute exercise on cognitive function: A meta-review of 30 systematic reviews with meta-analysesChang YK, et al. · Psychological bulletin · 2025PMID 39883421 ↗04Ginkgo biloba extract EGb 761 is safe and effective in the treatment of mild dementia - a meta-analysis of patient subgroups in randomised controlled trialsRiepe M, et al. · The world journal of biological psychiatry : the official journal of the World Federation of Societies of Biological Psychiatry · 2025PMID 39895346 ↗05Associations between Diet and Cognitive Function in Stroke Survivors: A Systematic Review and Meta-analysisAmanat S, et al. · Advances in nutrition (Bethesda, Md.) · 2025PMID 40355028 ↗06Creatine Supplementation in Combat Sport Athletes: A Narrative Systematic ReviewAshtary-Larky D, et al. · Journal of dietary supplements · 2025PMID 40755023 ↗Community experiences
Contributors volunteered; this does not establish treatment effectiveness or population incidence.
Reported changes
No publishable community breakdown is available. This does not establish that no reports exist.