Improvement after a supplement is not the same as a comparative result
Start with the comparison. A before-and-after change alone cannot isolate the contribution of an ingredient.
Vitamin B12
Selected research topic
Exercise performance
The confirmed comparison studies tested several ingredients together. They cannot isolate the effect of this ingredient.
Some findings concern patients or people with a deficiency.
- Publications for this topic
- 2
- Human comparison publications
- 1
- Publications needing review
- 1
Findings in the studies
Physical performance level
- No clear difference from the comparison group was found.
Several ingredients were tested together, so this ingredient’s individual effect is unknown.
Patient group · Combination study · 2 yearsMeasurement and study conditions
- Study type
- Randomized controlled trial: subjects were randomly assigned to groups for comparison.
- Study population
- Human participants · Patient group
- Ingredients tested
- Ingredient combination
- How results were compared
- Results were compared between groups. · Between-group comparison
- Additional measurement information
- Primary outcome
- Measurement time
- 2 years
This result is held for interpretation. That does not mean research found no effect.
Outcome groups needing additional review (1)
- neurological functional recovery · Distinct papers needing additional review: 1Direction unclear: 1
One paper can appear under multiple measured outcomes or review reasons, so these counts should not be added together.
Representative outcome and study details
Human studies reported no clear between-group difference in Physical performance level.
combination-ingredient studies · Individual ingredient effects cannot be separated · Human studies · Includes patient groups · between-group comparison
1 publications linked to this result
- Route, form, dose, or population details are incomplete, so the findings cannot be confirmed as directly comparable.
- Combination, formula, or class studies do not isolate this ingredient or establish synergy.
Data coverage and detailed study classifications
Paper counts are separated by research topic below. One paper may contribute to multiple findings.
Analysis status: Public-ready
Ingredient analysis date:
How the grade was determined: B
The 57.4 evidence score includes 1 independent human studies and 1 clinical studies in the representative benefit area. The B tier remains conservative because of the evidence centers on contextual or measured outcomes rather than general-use effects, limited repetition across independent human clinical studies.
The grade is based mainly on the research area with the most evidence. It does not mean the same result was found in other areas.
Papers linked to this ingredient overall: 96
Papers linked to this topic 2 · distinct papers 2 · papers with a confirmed human comparison 1 · papers needing additional review 1
A publication may appear in more than one count. These numbers should not be added. Ingredient-wide papers, topic-linked papers, and sources in outcome groups use different scopes. Adding source counts may count the same paper more than once.
- neurological functional recovery: Sources represented in this measurement group: 1 · Distinct papers with human comparisons for this outcome: 0
- Physical performance level: Sources represented in this measurement group: 1 · Distinct papers with human comparisons for this outcome: 1
What the research found
Physical performance level
No clear difference in this measurement was found between the compared groups.
Controlled study in people · Ingredient combination · Patient group
Several ingredients were used together. This does not establish the effect of this ingredient alone or synergy.
Between-group comparison
Analysis coverage and paper counts
1 paper · 1 measured outcome
Direction counts are distinct papers within each row. Outcome contributions count endpoint results, so one paper may contribute more than once.
neurological functional recovery
The study needs further checking before its result can be interpreted.
Other evidence · Single ingredient · Patient group
The comparison could not be confirmed.
Analysis coverage and paper counts
1 paper · 1 measured outcome
1 papers held from direction counts
Direction counts are distinct papers within each row. Outcome contributions count endpoint results, so one paper may contribute more than once.
How to read research findings
How should I read research findings?
Research guidesNo clear difference and an uninterpretable result are different
A reported null comparison contains a result. An abstract without an interpretable comparison leaves a question unresolved.
Paper counts and study counts are different
Count original research separately from research that reanalyzes it. Publication volume is neither replication nor a quality rating.
Side effects and combination findings
Findings from this ingredient alone are shown separately from those involving another supplement or medication.
No reviewed caution rules are available yet. Reported caution findings are shown below.
Findings to review with care
Side effects reported for the ingredient alone are separated from findings involving another supplement or medication.
Cautions reported with another supplement or medication
These studies reported worsening outcomes, reduced absorption, or other cautions with combined use. They do not predict an individual's outcome.
AntacidsAntacids may alter vitamin B12 absorption and utilization, increasing deficiency risk.
MetforminMetformin-treated T2DM patients are at higher risk of vitamin B12 deficiency and more severe neuropathy symptoms; supplementation may prevent or treat these conditions.
Proton pump inhibitorsPPI use may impact the absorption of vitamin B12, resulting in a slightly increased risk of deficiency.