Key findings from detailed records
A 12-month trial in 50 adults aged 55–87 reported fewer infections and lower selected inflammatory and oxidative-stress markers with zinc than placebo. It used 45 mg elemental zinc/day, a study dose rather than a routine intake recommendation. Treating an existing cold with lozenges is a separate question. PMID 17344507
KNOWLEDGE RECORD
- Category
- Vitamins and minerals
- Last Reviewed
Names and related search termsZinc / Zinc / Zn / Zinc lozenges
Study type: human intervention study.
OUTCOME-SPECIFIC EVIDENCE
Scientific Evidence Profile
Assessment pending
An outcome-specific assessment has not yet been completed. This is not a finding that the ingredient is ineffective. The study records below remain available.
This profile concerns the stated outcome and population, not the ingredient as a whole. It is not a probability of benefit, a safety rating, a product efficacy rating or an indication of product adoption.
How we assess evidenceIngredient Profile
- What is it, and where is it found?
- Zinc is an essential mineral found in meat, seafood and other foods. The chemical salt and the amount of elemental zinc are separate pieces of information. [1]
Sources for this profile
Compound properties and formulation properties are different. These sources do not establish the efficacy of a finished supplement.
- NIH Office of Dietary Supplements — Zinc Nutrient identity and food-source reference. Published by NIH Office of Dietary Supplements. Reference synthesis; not an individual clinical trial.
Profile sources checked:
Read the evidence in context
- Evidence: what was measured in the stated population or experimental model.
- Inference: an interpretation connecting findings; its applicability depends on the study conditions.
- Hypothesis: a proposed explanation or effect that remains to be tested.
Why It Matters #
Zinc: what do human trials tell us about immune function and different formulations?
What Was Studied #
50 adults aged 55–87
Randomized double-blind placebo-controlled trial · 12 months PMID 17344507
What Was Found #
Fewer infections and lower selected inflammatory/oxidative markers than placebo were reported. Plasma zinc increased. PMID 17344507
What the Evidence Means #
Small older-adult sample; 45 mg is a study dose, not a routine intake recommendation. This does not establish effects at low nutritional doses or treatment of an existing cold. PMID 17344507
What We Can Learn #
A year-long nutrition trial in older adults asks a different question from a short course of lozenges after a cold starts. Route, dose and nutritional status determine which study is relevant to a reader’s question.
What Remains Unknown #
Further questions include reproducibility across populations and formulations, and the long-term balance of benefits and harms. Use the literature map as a starting point for these questions.
LITERATURE MAP / 10 PAPERS
Compare papers by conditions and findings.
A literature map covering different populations, outcomes and formulations. Read alongside detailed records to avoid treating one trial as the conclusion for an entire ingredient.
Selected: 2026-09-21. Bibliographic information checked against Europe PMC / PubMed. Editorial selection considered major papers and a range of populations and questions. This is not a systematic search covering all recent research.
11 RECORDS
A dash marks fields outside the bibliographic record. Use detailed records to compare findings and design records to connect mechanisms.
No papers match. Change the search conditions.
The literature map is an index of research questions and references. Individual assessment of results, doses, funding and COI is limited to the detailed study records. Related reports from the same trial may be included; paper counts are not counts of independent trials.
Explore the research Study Records
Listed doses describe study conditions, not recommended intake.
Zinc supplementation decreases incidence of infections in the elderly: effect of zinc on generation of cytokines and oxidative stress.
PubMed 17344507DOI: 10.1093/ajcn/85.3.837
- Authors
- Prasad AS, Beck FWJ, Bao B, Fitzgerald JT, Snell DC, Steinberg JD, Cardozo LJ.
- Journal
- The American Journal of Clinical Nutrition
- Publication year
- 2007
- Study design
- Randomized double-blind placebo-controlled trial
- Participants
- 50 adults aged 55–87
- Dose and intervention
- Zinc gluconate supplying 45 mg elemental zinc/day
- Duration
- 12 months
- Outcomes and their role in the study
- Primary: infections. Secondary: cytokines and oxidative-stress markers.
- Findings
- Fewer infections and lower selected inflammatory/oxidative markers than placebo were reported. Plasma zinc increased.
- Limitations
- Small older-adult sample; 45 mg is a study dose, not a routine intake recommendation. This does not establish effects at low nutritional doses or treatment of an existing cold.
- Funding
- Supported by an NIH grant and Labcatal Laboratories, Paris, as stated on the publisher record.
- Conflict of Interest
- Not verified in the abstract reviewed.
- Scope of source review
- The original abstract was checked for population, dose, duration and results; available source disclosures were checked separately. Any unverified disclosure details remain identified above.
Zinc acetate lozenges for the treatment of the common cold: a randomised controlled trial.
PubMed 31980506DOI: 10.1136/bmjopen-2019-031662
- Authors
- Hemilä H, Haukka J, Alho M, Vahtera J, Kivimäki M.
- Journal
- BMJ open
- Publication year
- 2020
- Study design
- Randomized placebo-controlled trial of zinc acetate lozenges
- Participants
- 253 people randomized in advance; 87 included in the primary analysis after developing a cold.
- Dose and intervention
- Trial conditions: six lozenges daily, each containing 13 mg elemental zinc, for up to 5 days
- Duration
- Recovery assessed over 10 days after onset
- Outcomes and their role in the study
- Rate of recovery from a cold
- Findings
- Recovery rate ratio: 0.68 (95% CI 0.42–1.08). Recovery was not significantly accelerated under these conditions, and taste-related adverse events occurred.
- Limitations
- A particular lozenge used briefly. Distinguish it from nutritional tablets and findings from other zinc trials.
- Funding
- Supported by NordForsk and the Academy of Finland. University Pharmacy supplied trial lozenges.
- Conflict of Interest
- The authors declared no competing interests. University Pharmacy donated the lozenges and had no role in trial planning, conduct, interpretation or manuscript writing.
- Scope of source review
- Bibliographic information and abstract checked, along with relevant funding and conflict-of-interest sections in the public full text. This is not a comprehensive critical appraisal of the full paper.
Cite this page
LÍFSVARÐA. Zinc: what do human trials tell us about immune function and different formulations? / Updated 2026-10-24
https://lifsvarda.com/knowledge/zinc/Edited by LÍFSVARÐA (product brand).Editorial policy
Safety and interactions
Assess elemental zinc from all supplements together, including cold lozenges. Sustained high intake can impair copper absorption and cause copper deficiency. Zinc can reduce absorption of tetracycline or quinolone antibiotics and penicillamine. Discuss dose, duration and timing with a clinician or pharmacist; a high-dose research regimen is not a routine daily recommendation.
Safety section reviewed: 2026-10-24.
Sources and updates
- Prasad AS, Beck FWJ, Bao B, Fitzgerald JT, Snell DC, Steinberg JD, Cardozo LJ. (2007). Zinc supplementation decreases incidence of infections in the elderly: effect of zinc on generation of cytokines and oxidative stress.
- Hemilä H, Haukka J, Alho M, Vahtera J, Kivimäki M. (2020). Zinc acetate lozenges for the treatment of the common cold: a randomised controlled trial.Bibliographic information and abstract checked, along with relevant funding and conflict-of-interest sections in the public full text. This is not a comprehensive critical appraisal of the full paper.
2026-10-11: Human-study coverage, findings and comparisons reviewed. Source-review scope is stated for each study.