CHAMGAP
Verdict No. 3111 · Search date 2026-09-16 · Methodology v1.0

Oral dispersible methylcobalamin,
does it really help with Reduction in reported painDETECT score in metformin-treated diabetic neuropathy with low B12?

30-Second Summary
C
Evidence Grade C · 46 · Safety caution
ChatGPT source review and self-verification · Codex technical integration
This current value describes the evidence for this narrow score comparison. Mean pain NRS/VAS efficacy, a registered primary pain outcome, adjusted CI and MCID were not verified. New full text, registration data or corrections trigger versioned updates at the same assigned ID/URL.
Caution. No suspected B12-related adverse events were reported in the limited trial, but group denominators for all adverse events, serious events and long-term or special-population safety remain unverified. Warnings for other cobalamin products are not transferred into an incidence for this formulation. The trial dose is not an individual dosing or diabetes/analgesic medication-change instruction. [S01][S07][S08][S09]
What the
research shows
One placebo-controlled trial reported a significant between-group change test for the painDETECT-linked score. This is a screening composite of neuropathic pain characteristics, not mean pain-intensity NRS. The adjusted effect, CI and an applicable clinical-importance threshold remain unverified. Findings are not generalized beyond low-B12, long-term metformin users to universal analgesic efficacy. [S01][S04]
What the
ads claim
Improved serum B12 or nerve conduction cannot be relabeled as reduced mean pain intensity, a replacement for analgesics, or benefit in all diabetic neuropathy. The current manufacturer page neither verifies historical batch identity nor independently confirms efficacy. [S01][S10]

Four separate assessment dimensions

Effect direction and sizeIn one placebo-controlled trial, the reported 12-month painDETECT score changed from 18.4 to 17.1 with methylcobalamin and from 19.3 to 20.9 with placebo. The change comparison adjusted for HbA1c and glycemic medication had P<0.001, but the adjusted coefficient, standard error and confidence interval were not reported.
Evidence certaintyThe axes are B / P / R1 / I1 / EX / B2 / CX. There is one decisive trial family at the exact boundary, with small size, unreported operational allocation concealment, and an unavailable adjusted effect and confidence interval.
ApplicabilityThe claim is limited to methylcobalamin 1000 micrograms/day for 12 months in adults with type 2 diabetes, peripheral/autonomic neuropathy, metformin use for at least 4 years and B12 below 400 pmol/L. It is not generalized to mean pain NRS/VAS or all diabetic neuropathy.
SafetyNo suspected B12-related adverse events were reported in the limited trial, but arm-level denominators for all and serious adverse events and long-term or special-population safety remain unverified. The trial dose is not individual dosing or medication-change advice.

EX applies because the formal adjusted analysis lacks its effect estimate and confidence interval while only P<0.001 is available. The raw change difference of -2.9 points and endpoint difference of -3.8 points are descriptive, not the formal adjusted estimate; the fixed rubric yields C with 46 points.

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Useful facts when choosing a product

  • B12 fix by UNI-PHARMA is an oral dispersible single-active methylcobalamin product. Other cobalamins, injections and mixtures were not merged. [S01][S10]
  • The trial used 1000 µg daily for 12 months. Diet, fortified foods, total added supplement exposure and numerical adherence are unverified. [S01]
  • Similar-looking placebo and shared glycemic management were used. Analgesics were restricted except occasional paracetamol for 2–3 days; actual rescue use is unverified. [S01]
  • The current manufacturer page has an unresolved 1000 µg/1000 mg labeling conflict. The trial dose follows the original paper: 1000 µg/day. [S01][S10]
ID

Chamgap Semantic Classification Code

Permanent code issued

S.methylcobalamin.oral-dispersible-1000mcg-daily-12months.metformin-longterm-low-b12-type2-diabetic-neuropathy-paindetect-score.decrease.matched-placebo-same-background-care

Substances > Methylcobalamin monotherapy > Oral dispersible 1000 micrograms/day for 12 months > painDETECT score in metformin-treated type 2 diabetic neuropathy with low B12 > Decrease > Matched placebo under the same background care

Fixed to the reported painDETECT score and kept separate from mean pain NRS/VAS, other cobalamins, routes or doses, and all diabetic neuropathy. The code identifies the intervention and claim; it never contains the evidence grade, score, or safety result.

Download semantic index (JSON) · Codebook v1

Exact Claim Classification

These independent facets prevent evidence from different forms, routes, populations, effects, and comparators from being mixed.

Intervention classS · Supplement or nutraceutical
Canonical ingredient or interventionMethylcobalamin (mecobalamin), vitamin B12 as the sole added active ingredient
Source or part usedManufacturing source, batch and purity unverified; no substitution of other cobalamins
Formulation or processingB12 fix, UNI-PHARMA; oral dispersible tablet. Historical batch and placebo excipients unverified
RouteOral dispersible; no inferred sublingual holding time or injection route
Dose1000 µg once daily; total dietary and additional supplement exposure unverified
Duration12 months
PopulationAdults with T2D and peripheral/autonomic neuropathy; metformin ≥4 years, B12 <400 pmol/L; stable HbA1c 6.5–7.5%; pain-entry threshold unverified
Effect or conditionDecrease in the reported painDETECT neuropathic pain-characteristics score, distinct from average pain-intensity reduction
Primary endpointPage endpoint: between-group change comparison in reported painDETECT score at 12 months; registered primary status unverified
ComparatorSimilar-appearance placebo; stable glycemic care, restricted other analgesics and occasional paracetamol allowed
Duplicate-detection keyproposed|methylcobalamin|B12-fix-oral-dispersible|1000-ug-daily|12-months|T2D-DPN-DAN-metformin-ge4y-B12-lt400pmolL|reported-painDETECT-score|placebo-same-care
01

What the research actually shows

Of 90 participants, 44 received active treatment and 46 placebo; all were reported to complete. Table 4 scores were 18.4→17.1 versus 19.3→20.9. The change comparison adjusted for HbA1c and glycemic medication had P<0.001. The arithmetic change difference is -2.9 points and endpoint difference -3.8 points; neither is the unpublished adjusted estimate. [S01]

02

Why this is classified as C (46)

C·46 points, B/P/R1/I1/EX/B2/CX. The supplied engine and fixed score table were replayed. The formal analysis is adjusted ANCOVA but its coefficient, SE and CI are absent and P is only <0.001, meeting EX(a) under precedent30. Unadjusted mean differences were not substituted, and standardized effects were not reported because endpoint-specific analysis denominators are unverified. Small size and absent allocation-concealment implementation reporting yield B2; in-kind product supply with no external funding reported yields I1. Zero strengths does not mean zero effect.

Counterpoint. Between-group P=0.607 for MNSIE and P=0.876 for HbA1c were retained. Nonsignificance on other outcomes was not turned into painDETECT disproof or equivalence. The baseline SD conflict of 9.2 versus 9.7 was not silently resolved. [S01]

Rejudgment record. Positive direct score-change test, but the magnitude of clinically important pain relief is unverified — Supplied precedents28/30/44 and bias axis6; C fixed anchor with zero strengths

Stored scoring profile
EndpointPSymptom or function itself is the target - including patient reports and performance tests
ReplicationR1Single confirmatory trial
IndependenceI1Mixed funding sources
Effect sizeEXThe clinical size of the effect could not be judged
PrecisionCXNo pooled confidence interval could be confirmed

Stored derived and displayed grades match; this is not a current recalculation or validity check (C).

Review performed and remaining limitations

The evidence cutoff is 2026-09-16 and review was single-assistant ChatGPT self-review. This is not independent external clinical review, journal certification or a guarantee of exhaustive retrieval; new evidence, corrections or errors trigger updates at the same ID and URL.

Pain-entry criteria, questionnaire version and recall period, registry hierarchy, protocol, SAP, adjusted effect, SE and CI, endpoint-specific denominator, applicable MCID, baseline-SD conflict, batch, purity, placebo composition, dietary exposure and adherence remain unverified.

03

Evidence Table

StudyDesignSampleFundingEndpointResultWeight
Didangelos et al. 2021. Vitamin B12 Supplementation in Diabetic Neuropathy: A 1-Year, Randomized, Double-Blind, Placebo-Controlled TrialRandomized double-blind placebo-controlled trial44/46 assigned and reported completed; endpoint denominator not separately reportedNo external funding; active/placebo suppliedPage endpoint: between-group change comparison in reported painDETECT score at 12 months; registered primary status unverifiedOf 90 participants, 44 received active treatment and 46 placebo; all were reported to complete. Table 4 scores were 18.4→17.1 versus 19.3→20.9. The change comparison adjusted for HbA1c and glycemic medication had P<0.001. The arithmetic change difference is -2.9 points and endpoint difference -3.8 points; neither is the unpublished adjusted estimate. [S01]One decisive family
Yaqub, Siddique, Sulimani. 1992. Effects of methylcobalamin on diabetic neuropathyAdjacent study; not exact replicationDenominator for the selected comparison unverified in available materialUnverifiedDifferent symptoms/dose comparisonThe 1992 abstract reports improved somatic/autonomic symptoms but nonsignificant nerve-conduction changes at 4 months. Exact painDETECT between-group values, matched population and dose were not verified. [S05]Adjacent; not counted
Mansour et al. 2026. Efficacy of Oral Vitamin B-12 at 1000 micrograms Compared with 2000 micrograms on Neuropathic OutcomesAdjacent study; not exact replicationDenominator for the selected comparison unverified in available materialUnverifiedDifferent symptoms/dose comparisonThe confirmed 2026 title compares active oral B12 doses of 1000 µg and 2000 µg. It has no no-supplement comparator, and direct pain figures were not verified from the accessed metadata. [S06]Adjacent; not counted
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Receipt — 12 References

Evidence access cutoff: 2026-09-16. Each citation states its actual access level (full-text transcription, abstract, index, or other) and remaining limitations. Bibliographic checking does not certify the study results or treatment efficacy.

Didangelos et al. 2021. Vitamin B12 Supplementation in Diabetic Neuropathy: A 1-Year, Randomized, Double-Blind, Placebo-Controlled Trial
The trial allocated 90 participants to methylcobalamin (44) or placebo (46) and reports that all completed 12 months. Separate endpoint-specific analysis denominators were not reported.
checked
Didangelos et al. — NLM bibliographic record
Discovery source; not counted as direct efficacy.
checked
ClinicalTrials.gov NCT04706377
The registration identifier was confirmed, but first-posting date, change history, pain-outcome hierarchy and a prespecified analysis plan could not be verified with the available access.
checked
Freynhagen et al. 2006. painDETECT: a new screening questionnaire to detect neuropathic components in patients with back pain
The original paper-form score ranges from -1 to 38. It combines sensory qualities, pain course and radiation; questions recording pain intensity are not included in this score.
checked
Yaqub, Siddique, Sulimani. 1992. Effects of methylcobalamin on diabetic neuropathy
An older methylcobalamin trial reported somatic/autonomic symptom improvement but nonsignificant conduction changes at 4 months. It was not established as a replicate with the same pain scale, dose and population.
checked
Mansour et al. 2026. Efficacy of Oral Vitamin B-12 at 1000 micrograms Compared with 2000 micrograms on Neuropathic Outcomes
The 2026 trial compares oral B12 1000 µg with 2000 µg. It is not a no-B12 comparison and was not counted as replication of the placebo comparison.
checked
MHRA. Metformin and reduced vitamin B12 levels: new advice for monitoring patients at risk
The metformin/low-B12 relationship is safety and population context. It does not establish methylcobalamin pain efficacy or justify individual medication changes.
checked
MHRA. Vitamin B12 (hydroxocobalamin, cyanocobalamin): cobalt sensitivity reactions
The cobalt-sensitivity notice explicitly names hydroxocobalamin and cyanocobalamin. It was not transferred into an adverse-event incidence for the methylcobalamin trial.
checked
NIH ODS. Vitamin B12: Fact Sheet for Health Professionals — supplied record 110 citation
The NIH statement that no UL is established was inherited from the supplied record. It is not unlimited-safety assurance for long high-dose use or every special population.
checked
UNI-PHARMA. B12 fix product and food-supplement catalogue
The current manufacturer page contains both 1000 µg and 1000 mg labels. The trial dose remains 1000 µg/day from S01; that product page does not verify the trial batch.
checked
Jayabalan et al. 2016. Vitamin B supplementation for diabetic peripheral neuropathy
Discovery source; not counted as direct efficacy.
checked
Mandra et al. 2026. Vitamin B Supplementation for Diabetic Peripheral Neuropathy: A Review and Meta-Analysis
Discovery source; not counted as direct efficacy.
checked
Published as a current value with uncertainty disclosed; Codex performs only identifier, format, build and deployment checks.
Technical integration by: Codex · Evidence date: 2026-09-16 · Corrections: none

Cite this verdict

Does oral methylcobalamin lower the painDETECT score in diabetic neuropathy with low B12? Evidence Grade C card
[Chamgap] Does oral methylcobalamin lower the painDETECT score in diabetic neuropathy with low B12? — Evidence Grade C·46. 12 cited sources checked. Source: https://chamgap.com/en/verdicts/blood-sugar/methylcobalamin-metformin-low-b12-diabetic-neuropathy-paindetect-12-months/ · CC BY 4.0

CC BY 4.0 — free to use with attribution; do not distort grades, numbers, or verdict meaning.

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What this document does and does not do

Chamgap is an information source. It reports what research has and has not confirmed; it does not tell readers what to take or buy. That decision belongs to readers and, when needed, medical or legal professionals. This verdict reflects literature available up to the search date and may change as new research appears. Nothing here is medical advice.