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.
Zinc
Selected research topic
Glucose and metabolic health
Some measured outcomes improved in human comparison studies. Read these findings with their populations and conditions.
Findings from a combination study cannot be attributed to this ingredient alone.
Some findings concern patients or people with a deficiency.
- Publications for this topic
- 12
- Human comparison publications
- 3
- Publications needing review
- 6
Findings in the studies
Body weight
Publications linked to this measurement: 2
Human comparison research
- A better result than the comparison group was reported.
What the comparison group used was not confirmed.
Patient group · Single ingredientMeasurement and study conditions
- Study type
- Randomized controlled trial: subjects were randomly assigned to groups for comparison.
- Study population
- Human participants · Patient group
- Ingredients tested
- Single ingredient
- How results were compared
- Results were compared between groups.
- Measurement time
- Not confirmed.
Review of existing studies · population needs confirmation
- A result was reported, but the comparison could not be confirmed.Single ingredient
Measurement and study conditions
- Study type
- Meta-analysis
- Study population
- Study subject not identified
- Ingredients tested
- Single ingredient
- Measurement time
- Not confirmed.
Fasting plasma glucose
Publications linked to this measurement: 1
- A better result than the comparison group was reported.
Several ingredients were tested together, so this ingredient’s individual effect is unknown.
What the comparison group used was not confirmed.
Patient group · Combination studyMeasurement 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.
- Measurement time
- Not confirmed.
HbA1C
Publications linked to this measurement: 2
Human comparison research
- A better result than the comparison group was reported.Patient group · Single ingredient · 90 days
Measurement and study conditions
- Study type
- Randomized controlled trial: subjects were randomly assigned to groups for comparison.
- Study population
- Human participants · Patient group
- Ingredients tested
- Single ingredient
- How results were compared
- Results were compared between groups. · Study comparison: Zinc alone vs placebo; other arms included curcumin alone and zinc+curcumin
- Additional measurement information
- Secondary outcome
- Measurement time
- 90 days
Research with unclear study subject or type
- The study reported improvement in this measurement.
Several ingredients were tested together, so this ingredient’s individual effect is unknown.
What the comparison group used was not confirmed.
Combination studyMeasurement and study conditions
- Study type
- Other evidence
- Study population
- Recorded population category: Patient group. Whether the research involved humans needs confirmation.
- Ingredients tested
- Ingredient combination
- How results were compared
- Results were compared between groups.
- Measurement time
- Not confirmed.
insulin
Publications linked to this measurement: 1
- A better result than the comparison group was reported.Patient group · Single ingredient · 90 days
Measurement and study conditions
- Study type
- Randomized controlled trial: subjects were randomly assigned to groups for comparison.
- Study population
- Human participants · Patient group
- Ingredients tested
- Single ingredient
- How results were compared
- Results were compared between groups. · Study comparison: Zinc alone vs placebo; other arms included curcumin alone and zinc+curcumin
- Additional measurement information
- Secondary outcome
- Measurement time
- 90 days
Other measured outcomes (6)
IS%
Publications linked to this measurement: 1
- A better result than the comparison group was reported.Patient group · Single ingredient · 90 days
Measurement and study conditions
- Study type
- Randomized controlled trial: subjects were randomly assigned to groups for comparison.
- Study population
- Human participants · Patient group
- Ingredients tested
- Single ingredient
- How results were compared
- Results were compared between groups. · Study comparison: Zinc alone vs placebo; other arms included curcumin alone and zinc+curcumin
- Additional measurement information
- Secondary outcome
- Measurement time
- 90 days
Fasting blood glucose
Publications linked to this measurement: 1
Review of existing studies · population needs confirmation
- The study reported improvement in this measurement.
What the comparison group used was not confirmed.
Single ingredientMeasurement and study conditions
- Study type
- Meta-analysis
- Study population
- Study subject not identified
- Ingredients tested
- Single ingredient
- How results were compared
- Results were compared between groups.
- Measurement time
- Not confirmed.
fasting glucose
Publications linked to this measurement: 1
Review of existing studies · population needs confirmation
- The study reported improvement in this measurement.
What the comparison group used was not confirmed.
Measurement and study conditions
- Study type
- Meta-analysis
- Study population
- Recorded population category: Patient group. Whether the research involved humans needs confirmation.
- Ingredients tested
- Unknown intervention
- How results were compared
- Results were compared between groups.
- Measurement time
- Not confirmed.
Insulin resistance
Publications linked to this measurement: 1
Review of existing studies · population needs confirmation
- The study reported improvement in this measurement.
What the comparison group used was not confirmed.
Single ingredientMeasurement and study conditions
- Study type
- Meta-analysis
- Study population
- Study subject not identified
- Ingredients tested
- Single ingredient
- How results were compared
- Results were compared between groups.
- Measurement time
- Not confirmed.
weight-for-age Z-score
Publications linked to this measurement: 1
Review of existing studies · population needs confirmation
- A result was reported, but the comparison could not be confirmed.Single ingredient
Measurement and study conditions
- Study type
- Meta-analysis
- Study population
- Study subject not identified
- Ingredients tested
- Single ingredient
- Measurement time
- Not confirmed.
weight-for-height Z-score
Publications linked to this measurement: 1
Review of existing studies · population needs confirmation
- A result was reported, but the comparison could not be confirmed.Single ingredient
Measurement and study conditions
- Study type
- Meta-analysis
- Study population
- Study subject not identified
- Ingredients tested
- Single ingredient
- Measurement time
- Not confirmed.
Representative outcome and study details
Human studies reported between-group improvement in Body weight; while Studies with an unspecified organism reported a result with no confirmed comparison group in Body weight.
These conditions come from related studies and may not describe a single paper.
Single-ingredient studies · Human studies · Includes patient groups · Population not specified · between-group comparison · comparator not confirmed
2 publications linked to this result
- Study conditions differ; results are shown descriptively and are not pooled.
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 61.4 evidence score includes 2 independent human studies and 2 clinical studies in the representative benefit area. The B tier remains conservative because of limited repetition across independent human clinical studies, limited repeated evidence for directly felt outcomes.
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: 58
Papers linked to this topic 12 · distinct papers 12 · papers with a confirmed human comparison 3 · papers needing additional review 6
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.
- Body weight: Sources represented in this measurement group: 2 · Distinct papers with human comparisons for this outcome: 1
- Fasting blood glucose: Sources represented in this measurement group: 1 · Distinct papers with human comparisons for this outcome: 0
- fasting glucose: Sources represented in this measurement group: 1 · Distinct papers with human comparisons for this outcome: 0
- Fasting plasma glucose: Sources represented in this measurement group: 1 · Distinct papers with human comparisons for this outcome: 1
- HbA1C: Sources represented in this measurement group: 2 · Distinct papers with human comparisons for this outcome: 1
- insulin: Sources represented in this measurement group: 1 · Distinct papers with human comparisons for this outcome: 1
- Insulin resistance: Sources represented in this measurement group: 1 · Distinct papers with human comparisons for this outcome: 0
- IS%: Sources represented in this measurement group: 1 · Distinct papers with human comparisons for this outcome: 1
- weight-for-age Z-score: Sources represented in this measurement group: 1 · Distinct papers with human comparisons for this outcome: 0
- weight-for-height Z-score: Sources represented in this measurement group: 1 · Distinct papers with human comparisons for this outcome: 0
What the research found
body weight
The study reported improvement in this measurement.
Controlled study in people · Single ingredient · Patient group
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.
Fasting plasma glucose
The study reported improvement in this measurement.
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.
HbA1C
The study reported improvement in this measurement.
Controlled study in people · Single ingredient · Patient group
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.
insulin
The study reported improvement in this measurement.
Controlled study in people · Single ingredient · Patient group
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.
IS%
The study reported improvement in this measurement.
Controlled study in people · Single ingredient · Patient group
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.
Fasting blood glucose
The study reported improvement in this measurement.
Meta-analysis · Single ingredient · Unspecified population
Between-group comparison
Analysis coverage and paper counts
1 paper · 1 measured outcome
Review overlap with primary papers is unknown; counts stay separate.
Direction counts are distinct papers within each row. Outcome contributions count endpoint results, so one paper may contribute more than once.
fasting glucose
The study reported improvement in this measurement.
Meta-analysis · Unknown intervention · Patient group
Between-group comparison
Analysis coverage and paper counts
1 paper · 1 measured outcome
Review overlap with primary papers is unknown; counts stay separate.
Direction counts are distinct papers within each row. Outcome contributions count endpoint results, so one paper may contribute more than once.
HbA1c
The study reported improvement in this measurement.
Other evidence · 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.
Insulin resistance
The study reported improvement in this measurement.
Meta-analysis · Single ingredient · Unspecified population
Between-group comparison
Analysis coverage and paper counts
1 paper · 1 measured outcome
Review overlap with primary papers is unknown; counts stay separate.
Direction counts are distinct papers within each row. Outcome contributions count endpoint results, so one paper may contribute more than once.
Body weight
A result was reported, but the comparison could not be confirmed.
Meta-analysis · Single ingredient · Unspecified population
Analysis coverage and paper counts
1 paper · 1 measured outcome
Review overlap with primary papers is unknown; counts stay separate.
Direction counts are distinct papers within each row. Outcome contributions count endpoint results, so one paper may contribute more than once.
weight-for-age Z-score
A result was reported, but the comparison could not be confirmed.
Meta-analysis · Single ingredient · Unspecified population
Analysis coverage and paper counts
1 paper · 1 measured outcome
Review overlap with primary papers is unknown; counts stay separate.
Direction counts are distinct papers within each row. Outcome contributions count endpoint results, so one paper may contribute more than once.
weight-for-height Z-score
A result was reported, but the comparison could not be confirmed.
Meta-analysis · Single ingredient · Unspecified population
Analysis coverage and paper counts
1 paper · 1 measured outcome
Review overlap with primary papers is unknown; counts stay separate.
Direction counts are distinct papers within each row. Outcome contributions count endpoint results, so one paper may contribute more than once.
Unspecified measured outcome
The study needs further checking before its result can be interpreted.
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
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.
Unspecified measured outcome
The study needs further checking before its result can be interpreted.
Meta-analysis · Ingredient combination · Unspecified population
Several ingredients were used together. This does not establish the effect of this ingredient alone or synergy.
The comparison could not be confirmed.
Analysis coverage and paper counts
1 paper · 1 measured outcome
1 papers held from direction counts
Review overlap with primary papers is unknown; counts stay separate.
Direction counts are distinct papers within each row. Outcome contributions count endpoint results, so one paper may contribute more than once.
Unspecified measured outcome
The study needs further checking before its result can be interpreted.
Animal study · indirect · Single ingredient · Patient group
This finding comes from animal or cell research. It does not establish the same effect in people.
Between-group comparison
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.
Unspecified measured outcome
The study needs further checking before its result can be interpreted.
Controlled study in people · Single ingredient · Patient group
Between-group comparison
Analysis coverage and paper counts
1 paper · 3 measured outcomes
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.
Unspecified measured outcome
The study needs further checking before its result can be interpreted.
Meta-analysis · Single ingredient · Unspecified population
The comparison could not be confirmed.
Analysis coverage and paper counts
1 paper · 1 measured outcome
1 papers held from direction counts
Review overlap with primary papers is unknown; counts stay separate.
Direction counts are distinct papers within each row. Outcome contributions count endpoint results, so one paper may contribute more than once.
Unspecified measured outcome
The study needs further checking before its result can be interpreted.
Controlled human study · Unknown intervention · Unspecified population
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.
Unspecified measured outcome
The study needs further checking before its result can be interpreted.
Meta-analysis · Unknown intervention · Unspecified population
The comparison could not be confirmed.
Analysis coverage and paper counts
1 paper · 1 measured outcome
1 papers held from direction counts
Review overlap with primary papers is unknown; counts stay separate.
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.
Review 1 combination findings and 0 findings that outperformed an ingredient alone.
Findings to review with care
Side effects reported for the ingredient alone are separated from findings involving another supplement or medication.
Side effects reported with this ingredient alone
Symptoms or adverse events reported in studies without another active ingredient.
vomiting occurrence within 30 minutes after administration1 papers
Lower doses of zinc (5-10 mg/day) significantly reduced vomiting within 30 minutes of administration compared with 20 mg/day in children with acute diarrhea.Human studies · Randomized controlled trialReported improvements with combinations
Combination findings are grouped by how the study compared them. This is not a recommendation to combine ingredients.
Combinations with reported improvement
The combination showed improvement, but each ingredient's contribution is unclear.
마그네슘Co-supplementation with magnesium oxide and zinc sulfate resulted in significant improvements in glycemic control, lipid profiles, and inflammatory markers compared to placebo.