Vitamin B12,
does it really help with Reduction of CIS subjective-fatigue score in adults with IBD-related fatigue?
research showsWithin the documented search through 2026-09-16, no directly eligible between-group fatigue result was verified for oral B12 alone in adults with IBD-related fatigue. The current value is therefore ? with score null. This does not mean that human trials do not exist, that the effect is zero, or that treatments are equivalent. [S01; S05]
ads claimB12 participation in energy metabolism, a rise in serum B12, correction of anemia or a report of greater vitality cannot replace the placebo-controlled CIS fatigue outcome. This assessment does not recommend personal dosing or stopping existing treatment.
Four separate assessment dimensions
| Effect direction and size | Within the documented search through 2026-09-16, no directly eligible between-group fatigue result was verified for oral B12 alone in adults with IBD-related fatigue. The current value is therefore ? with score null. This does not mean that human trials do not exist, that the effect is zero, or that treatments are equivalent. [S01; S05] |
|---|---|
| Evidence certainty | No verified directly eligible result; not an inefficacy conclusion |
| Applicability | Adults 18–65 with IBD-related disabling fatigue and trial serum criterion B12 ≥150 pmol/L. Not pooled with IBS; detailed diagnosis, symptom duration and functional B12 status unverified |
| Safety | Caution. The accessed abstract does not establish arm-specific adverse events, serious adverse events, withdrawals or denominators; unknown is not zero. Eight-week evidence is not long-term high-dose safety evidence for pregnancy, lactation, children or hepatic/renal disease. No established UL is not unlimited safety assurance. Cobalt-sensitivity advice is linked to hydroxocobalamin/cyanocobalamin; Leber optic-neuropathy and early hypokalemia during intensive severe-megaloblastic-anemia treatment belong to the accessed cyanocobalamin injection label. These are not incidence data for the unverified oral formulation. Study doses are not personal dosing or medication-change instructions. [S01; S13–S15] |
The task-specific stage-zero rule applies because no directly eligible IBD-stratum contrast was verified. Claim type is B; endpoint, replication, independence, effect, bias and precision remain null; grade is ? and score null. Fatigue is conceptually a patient-reported symptom (P), but this does not populate a stage-zero scoring axis. The legacy calculator does not directly support the factual profile (no_human_study=false with downstream nulls); its diagnostics and separate gate projection are disclosed. [S17; audit/score_result.json]
Useful facts when choosing a product
- Only the oral B12 question is assessed. Cyanocobalamin, methylcobalamin, hydroxocobalamin or adenosylcobalamin is not assumed; product, salt, batch, purity and release type are unverified. [S01–S04]
- 1000 µg/day converts to 1 mg/day. Administrations per day, adherence, actual cumulative exposure, diet, fortified foods, additional B12 and background treatment are unverified. [S01; C03]
- Serum B12 ≥150 pmol/L is not treated as proof of normal MMA, homocysteine or holotranscobalamin. Symptom-duration threshold, IBD diagnosis/activity and anemia or mixed causes are unverified. [S01; S13]
Chamgap Semantic Classification Code
Permanent code issued
S.vitamin-b12-single-active.oral-1mg-daily-form-unverified-8weeks.ibd-related-disabling-fatigue-cis-subjective-fatigue.reduce.placebo-background-unverifiedSubstances > Vitamin B12 as sole added active > Oral 1 mg/day, form unverified, reported 8 weeks > CIS subjective fatigue in IBD-related disabling fatigue > Reduce > Placebo with background care unverified
Pooled IBS/IBD values were not attributed to the IBD stratum, yielding a stage-zero current value. The code identifies the intervention and claim; it never contains the evidence grade, score, or safety result.
Exact Claim Classification
These independent facets prevent evidence from different forms, routes, populations, effects, and comparators from being mixed.
| Intervention class | S · Supplement or nutraceutical |
|---|---|
| Canonical ingredient or intervention | Vitamin B12 as the sole added active ingredient; actual chemical form unverified |
| Source or part used | Manufacturing origin, batch and purity unverified; plant part not applicable |
| Formulation or processing | Oral B12 supplement; tablet/capsule, release type and product unverified; registry tablet snippet not promoted to actual trial formulation |
| Route | Oral, separated from sublingual, intramuscular, intravenous, nasal and transdermal routes |
| Dose | 1000 µg/day; per-administration dose, administrations per day and actual cumulative dose unverified |
| Duration | Reported 8 weeks; prospective primary-time hierarchy unverified |
| Population | Adults 18–65 with IBD-related disabling fatigue and trial serum criterion B12 ≥150 pmol/L. Not pooled with IBS; detailed diagnosis, symptom duration and functional B12 status unverified |
| Effect or condition | Reduction in subjective fatigue versus placebo, separate from anemia, vitality, motivation and cognition |
| Primary endpoint | Eight-week between-group change/adjusted estimate in CIS subjective-fatigue sum score (8–56, higher worse); IBD-stratum result and prospective subscale hierarchy unverified |
| Comparator | Placebo; matched background care is the target contract, but common treatment and placebo composition are unverified in the abstract |
| Duplicate-detection key | proposed|S|vitamin-b12-single-added-active|source-UNK|chemical-form-UNK|physical-form-UNK|oral|1000ug-daily|8wk-reported-not-prospectively-verified|adult18-65-IBD-disabling-fatigue-serumB12ge150pmolL|fatigue-reduction|CIS-subjective-fatigue|placebo-background-unverified|superiority-question |
What the research actually shows
The closest placebo-controlled trial pooled IBS and IBD. A separate IBD-stratum result was not verified; the Cochrane review also excluded it for lack of separately analysed data. The mixed-population result was not relabelled as an IBD effect. [S01; S05: excluded-studies table, printed p67] The claim was narrowed to subjective fatigue in IBD only. Hemoglobin recovery in B12-deficiency anemia, vitality in healthy adults, nasal ME/CFS treatment and sublingual fibromyalgia pre-post observations are different claims. Grades from existing B12 pages were not imported. [S01; S10; S11; S17] Scholten2018 included 95 IBS/IBD outpatients aged 18–65 with disabling fatigue and serum B12 ≥150 pmol/L, comparing oral B12 1000 µg/day with placebo for 8 weeks. Eight weeks is the reported observation horizon, not a verified uniquely prespecified primary time. Fatigue (CIS) was designated primary, but prospective subscale hierarchy, cause-specific analysis, chemical form and formulation were not verified. [S01–S04]
Why this is classified as ?
The task-specific stage-zero rule applies because no directly eligible IBD-stratum contrast was verified. Claim type is B; endpoint, replication, independence, effect, bias and precision remain null; grade is ? and score null. Fatigue is conceptually a patient-reported symptom (P), but this does not populate a stage-zero scoring axis. The legacy calculator does not directly support the factual profile (no_human_study=false with downstream nulls); its diagnostics and separate gate projection are disclosed. [S17; audit/score_result.json]
Counterpoint. The CIS subjective-fatigue subscale sums 8 items over 8–56 points, with higher scores worse. Its two-week recall is not the entry symptom-duration requirement. No MCID from another disease or scale is imported; trial language/version and an IBD between-group MCID remain unverified. [S06; S07]
Rejudgment record. Unscored stage-zero current value; ? reproduced under the declared legacy gate mapping — Supplied original rubric and unmodified calculator; task-specific rule for no verified directly eligible result
Review performed and remaining limitations
The closest placebo-controlled trial pooled IBS and IBD. A separate IBD-stratum result was not verified; the Cochrane review also excluded it for lack of separately analysed data. The mixed-population result was not relabelled as an IBD effect. [S01; S05: excluded-studies table, printed p67] The CIS subjective-fatigue subscale sums 8 items over 8–56 points, with higher scores worse. Its two-week recall is not the entry symptom-duration requirement. No MCID from another disease or scale is imported; trial language/version and an IBD between-group MCID remain unverified. [S06; S07]
Preliminary RoB 2-informed review — not a complete formal assessment
| Randomization | Randomized/double-blind reported; sequence/concealment unverified |
|---|---|
| Deviations from assigned interventions | Adherence and background treatment unverified |
| Missing outcome data | Arm n, ITT/PP and imputation unverified |
| Outcome measurement | CIS fatigue subscale; language/version/target MCID unverified |
| Selection of the reported result | Prospective subscale/time hierarchy and CI estimand unverified |
Reasons for the certainty judgment — not formal GRADE
| Risk of bias | Downstream stage-zero axes unscored |
|---|---|
| Inconsistency | No eligible result set for replication appraisal |
| Indirectness | Mixed IBS/IBD result not transferred to IBD stratum |
| Imprecision | Target CI unverified |
| Publication bias | Not assessable, not assumed absent |
Search scope and limitations. audit/search_log.json and audit/access_log.json
Evidence Table
| Study | Design | Sample | Funding | Endpoint | Result | Weight |
|---|---|---|---|---|---|---|
| Scholten et al. Surplus vitamin B12 use does not reduce fatigue in patients with IBS or IBD. Clin Nutr ESPEN. 2018. | Randomized placebo-controlled trial abstract; pooled IBS and IBD analysis | 95 total; analyzed denominator by arm unverified | Funding and product supply unverified | Eight-week CIS subjective-fatigue subscale; IBD-stratum contrast unverified | Pooled IBS/IBD changes were −8.1±9.5 with B12 and −8.3±10.6 with placebo, a descriptive +0.2-point difference. The meaning of ± and the estimand for the reported CI are unclear; this was not used as an IBD effect. | Excluded from target-effect grading |
Receipt — 17 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.
Technical integration by: Codex · Evidence date: 2026-09-16 · Corrections: none
Cite this verdict
[Chamgap] Does oral vitamin B12 alone reduce fatigue in adults with inflammatory bowel disease? — Evidence Grade ?. 17 cited sources checked. Source: https://chamgap.com/en/verdicts/energy/oral-vitamin-b12-ibd-fatigue-cis-8-weeks/ · CC BY 4.0CC BY 4.0 — free to use with attribution; do not distort grades, numbers, or verdict meaning.
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.