Safety Profile
Known Safety Concerns
- Cyanide moiety — theoretical concern in renal failure and tobacco amblyopia (rare)
- Very high serum B12 may be a marker of underlying malignancy — not a cause
- Parenteral large doses may cause acne-like skin eruptions (rare)
- May interact with metformin (metformin impairs B12 absorption)
Contraindications
- Cyanide moiety — theoretical concern in renal failure and tobacco amblyopia (rare)
- Very high serum B12 may be a marker of underlying malignancy — not a cause
Interactions
Information not yet available for this ingredient profile.
Evidence and Scientific Findings
Ingredient Overview
Cyanocobalamin is the most common synthetic form of vitamin B12 in supplements. It is water-soluble with a very high safety margin. Very high serum B12 levels are associated with certain malignancies (hepatocellular carcinoma, haematological cancers) though this is likely confounding — high B12 may be a marker, not a cause. Cyanocobalamin contains a cyanide moiety which is metabolised normally at supplement doses but may be relevant in cyanide metabolism disorders.
Biological and Chemical Classification
- Scientific Name
- Cyanocobalamin
Mechanism of Action
Information not yet available for this ingredient profile.
Clinical Evidence of Effectiveness
Information not yet available for this ingredient profile.
Pharmacokinetics
Information not yet available for this ingredient profile.
Recommended Dosage
Information not yet available for this ingredient profile.
SETI — Scientific Evidence Transparency Index
Executive Summary — Ingredient Assessment
- 10 studies reviewed
- 0 high-quality studies (meta-analysis or RCT)
- Main clinical benefit observed: Vitamin
- Evidence consistency: High consistency across studies (100%)
- Cyanide moiety — theoretical concern in renal failure and tobacco amblyopia (rare)
- Very high serum B12 may be a marker of underlying malignancy — not a cause
- Parenteral large doses may cause acne-like skin eruptions (rare)
- May interact with metformin (metformin impairs B12 absorption)
The available scientific evidence for Vitamin B12 (Cyanocobalamin) indicates notable safety signals that warrant caution. Use should be considered carefully and monitored, particularly in sensitive populations or alongside other medications.
Total SETI Score
High risk| Evidence quality | 10/40 |
| Evidence consistency | 20/20 |
| Safety signals | 0/20 |
| Study recency | 10/10 |
| Evidence transparency | 10/10 |
Evidence Summary
- 10 studies reviewed
- 0 high-quality studies (meta-analysis or systematic review)
- 0 studies identified benefits or no safety concern (GREEN)
- 10 studies reported limited or advisory safety evidence (YELLOW)
Evidence Policy
Only peer-reviewed scientific literature indexed in PubMed or comparable databases is included in this evaluation. Commercial websites, blogs, and marketing materials are excluded. All references include direct traceable links to source documents.
Last updated: 23 მარ 2026, 15:05
Evidence Distribution
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Observational / other LOW evidence YELLOWPopulation-based deprescribing strategy for proton pump inhibitors: health outcomes from a case-control study. ↗Echeverru00eda Gorriti A et al.. Population-based deprescribing strategy for proton pump inhibitors: health outcomes from a case-control study.. Med Clin (Barc). 2026. PMID:41832801.PMID 41832801 ↗Journal Med Clin (Barc)Year 2026Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41832801/
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Observational / other LOW evidence YELLOWAcquired Multiple Acyl-Coenzyme A Dehydrogenase Deficiency Associated With Sertraline in Sweden-A Nationwide Population-Based Study. ↗Sunebo S et al.. Acquired Multiple Acyl-Coenzyme A Dehydrogenase Deficiency Associated With Sertraline in Sweden-A Nationwide Population-Based Study.. Eur J Neurol. 2026. PMID:41808636.PMID 41808636 ↗Journal Eur J NeurolYear 2026Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41808636/
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Observational / other LOW evidence YELLOWAmelioration of postpartum hyperketonemia using amino acids, cyanocobalamin, inositol, u03b1-lipoic acid or monensin during the transition period of dairy cows. ↗Lisuzzo A et al.. Amelioration of postpartum hyperketonemia using amino acids, cyanocobalamin, inositol, u03b1-lipoic acid or monensin during the transition period of dairy cows.. J Dairy Sci. 2026. PMID:41780858.PMID 41780858 ↗Journal J Dairy SciYear 2026Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41780858/
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Observational / other LOW evidence YELLOWUnveiling the Pernicious Truth: A Case Report on the Rare Presentation of Severe Vitamin B12 Deficiency. ↗Akinola OO et al.. Unveiling the Pernicious Truth: A Case Report on the Rare Presentation of Severe Vitamin B12 Deficiency.. Cureus. 2026. PMID:41717155.PMID 41717155 ↗Journal CureusYear 2026Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41717155/
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Observational / other LOW evidence YELLOWScope for vitamin B deficiency redressal through microbial vitamins with reference to India and South Africa. ↗Nayak PP et al.. Scope for vitamin B deficiency redressal through microbial vitamins with reference to India and South Africa.. Crit Rev Biotechnol. 2026. PMID:41714150.PMID 41714150 ↗Journal Crit Rev BiotechnolYear 2026Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41714150/
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Observational / other LOW evidence YELLOWPMVE/MA-based microneedle patches for rapid transdermal delivery of vitamin B12: fabrication and evaluation. ↗Saurabh S et al.. PMVE/MA-based microneedle patches for rapid transdermal delivery of vitamin B12: fabrication and evaluation.. Drug Deliv Transl Res. 2026. PMID:41708905.PMID 41708905 ↗Journal Drug Deliv Transl ResYear 2026Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41708905/
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Observational / other LOW evidence YELLOWCobalt Toxicity. ↗Chen RJ et al.. Cobalt Toxicity.. 2026. PMID:36508548.PMID 36508548 ↗Year 2026Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/36508548/
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Observational / other LOW evidence YELLOWCompounded Semaglutide and Tirzepatide Products Use Unique Formulations but Efficacy and Safety Largely Unknown. ↗Belcourt J et al.. Compounded Semaglutide and Tirzepatide Products Use Unique Formulations but Efficacy and Safety Largely Unknown.. Ann Pharmacother. 2026. PMID:41689811.PMID 41689811 ↗Journal Ann PharmacotherYear 2026Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41689811/
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Observational / other LOW evidence YELLOWSelective Surface-Confinement and Elegant Sensing of Vitamin B12 on Hydroxyl-Functionalized Screen-Printed Carbon Electrode. ↗Yashly YK et al.. Selective Surface-Confinement and Elegant Sensing of Vitamin B12 on Hydroxyl-Functionalized Screen-Printed Carbon Electrode.. Langmuir. 2026. PMID:41685559.PMID 41685559 ↗Journal LangmuirYear 2026Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41685559/
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Observational / other LOW evidence YELLOWThiamine Deficiency After Bariatric Surgery: Early Neurological Complications and Nutritional Monitoring. ↗Remelhe Su00e1 S et al.. Thiamine Deficiency After Bariatric Surgery: Early Neurological Complications and Nutritional Monitoring.. Cureus. 2026. PMID:41635330.PMID 41635330 ↗Journal CureusYear 2026Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41635330/
Score Transparency
0 of 10 approved references (score saturates at 10). More peer-reviewed studies = stronger evidence base.
Method: Q = number of approved references ÷ 10 (capped at 1.0)
Limited — mostly case reports or animal studies
Method: L = mean study-level weight across approved references. Level 1 (meta-analysis / systematic review) = 1.0; Level 2 (RCT) = 0.8; Level 3 (cohort/case-control) = 0.6; Level 4 (case report) = 0.4; Level 5 (animal / in-vitro) = 0.2.
Mixed or neutral — roughly equal benefit and risk signals
Method: D = (sum of risk-scored references − sum of benefit-scored references) ÷ total evidence score, then scaled from [−1, 1] to [0, 1]. 0.0 = pure benefit; 0.5 = neutral; 1.0 = pure risk.
One or more monitoring-level safety signals active
Method: S = 0.5 (neutral baseline) + sum of active signal severity deltas ÷ 10. Severity deltas: Critical = +2.0, High = +1.5, Moderate = +1.0, Low = +0.5. Capped at 1.0.
Final GIRI Score for Vitamin B12 (Cyanocobalamin). Risk level thresholds: Low 0–3.0 · Moderate 3.0–5.5 · High 5.5–7.5 · Critical 7.5–10.
Full methodology & data sources
The GIRI Score is computed entirely from structured data — no editorial scoring or subjective weighting is applied at any step.
- References: Only approved references are counted. Each reference is assigned an evidence level (L1–L5) and a direction (risk / neutral / benefit) by the reference manager or AI classifier.
- Safety Signals: Sourced from regulatory agencies (FDA, EMA, Health Canada, TGA, and others) and pharmacovigilance databases. Only active signals count toward the score.
- Formula version: GIRI Score v3.7.0 — Q × L × D × S × 10.
- Limitations: The score reflects published evidence and recorded signals as of the last update date. It is not a clinical risk assessment and should not replace advice from a qualified healthcare professional.
Risk Level Classification
Based on available regulatory signals and scientific evidence, this ingredient presents a low safety concern under normal conditions of use.
0–3.0
3.0–5.5
5.5–7.5
7.5–10
The score pin shows exactly where this ingredient falls on the fixed risk scale.
What drove the Low classification for Vitamin B12 (Cyanocobalamin)
A score of 2.0 places this ingredient in the Low band. Thresholds: Low 0–3.0 · Moderate 3.0–5.5 · High 5.5–7.5 · Critical 7.5–10.
0 approved references.
Limited — mostly case reports or animal studies (Level 4–5).
Neutral or mixed — benefit and risk signals roughly balanced.
No active signals — S component is at neutral baseline (0.5), contributing no extra risk weight.
No major regulatory restrictions or advisories recorded across monitored jurisdictions (FDA, EMA, Health Canada, TGA, and others).
How are the Low / Moderate / High / Critical thresholds defined?
The four risk levels are fixed score bands. A score is assigned to exactly one level based on where it falls:
| Level | Score | Meaning |
|---|---|---|
| LOW | 0.0 – 2.9 | Sparse or predominantly beneficial evidence. No active safety alerts. |
| MODERATE | 3.0 – 5.4 | Mixed signals — some risk alongside benefit. Caution at high doses or in sensitive groups. |
| HIGH | 5.5 – 7.4 | Multiple studies or regulatory alerts documenting adverse effects. Professional oversight recommended. |
| CRITICAL | 7.5 – 10 | Regulatory restrictions in one or more major jurisdictions. Serious documented harm. Avoid without specialist supervision. |
Thresholds are fixed constants (GIRI_Score_Utils::LEVEL_THRESHOLDS). They do not change per ingredient and are never subject to editorial adjustment.