Evidence overview
Zinc
Zinc is an essential trace mineral with a substantial supplementation literature concentrated on common cold treatment, immune function, wound healing, age-related macular degeneration, and pediatric acute diarrhea. Several of its uses have strong clinical evidence anchored in Cochrane reviews and large-trial syntheses; others remain more contested. Form choice and timing of administration matter materially for some indications.
Most studied for
Coverage pending
PubMed coverage
Coverage pending
Safety profile
In your full report
Mechanism class
Essential trace mineral and cofactor for hundreds of enzymes including DNA and RNA polymerases,...
Study coverage
Study coverage by goal
PubMed counts for Zinc grouped by the goal each study targets.
Evidence overview is temporarily unavailable for Zinc.
Evidence
What the evidence covers
The terrain of the published literature, not its conclusions.
Zinc is one of the most-studied trace minerals in supplementation research, with a literature spanning common cold prevention and treatment, immune function, wound healing, age-related macular degeneration, pediatric acute diarrhea, taste and smell disorders, and male reproductive health. Supplemental forms vary substantially in bioavailability and tolerability: picolinate, gluconate, citrate, and carnosine are the most-common consumer forms, with picolinate often marketed for absorption, gluconate widely used in cold-lozenge research, and carnosine specifically studied for gastrointestinal-mucosa effects. Most trials use a single form, which means head-to-head form comparisons are thinner than the consumer market implies.
The outcome dimensions covered most heavily are upper respiratory infection (common cold) prevention and treatment, age-related macular degeneration (where zinc was a key component of the historically pivotal AREDS trials), pediatric acute diarrhea (where zinc reduces episode duration and severity - a WHO and UNICEF-endorsed public health intervention used in hundreds of millions of pediatric cases globally), wound healing in clinical and post-surgical contexts, and male reproductive markers including sperm parameters. Smaller research streams cover taste and smell recovery after viral infection and acne treatment.
Demographically, the literature is unusually broad across populations: AREDS-era trials concentrate on older adults with macular degeneration; pediatric diarrhea trials enroll children primarily in low-resource settings (where the public-health relevance is highest); common cold trials enroll healthy adults across age ranges. Form selection and timing of administration are unusually consequential for the cold use specifically - the literature concentrates heavily on lozenge formulations with gluconate or acetate forms started within 24 hours of symptom onset, while research on daily oral capsules for the same outcome is thinner.
Safety
Safety summary
Common adverse events, drug interactions, and special populations.
Zinc is generally well-tolerated at typical supplemental doses of 15-40 mg/day. The IOM tolerable upper limit for adults is 40 mg/day; chronic intakes above this can cause copper deficiency because zinc and copper compete for absorption, which is a well-documented adverse effect of long-term high-dose supplementation. Acute adverse effects include nausea, vomiting, and abdominal cramping, which are more common with picolinate or gluconate taken on an empty stomach, along with a metallic taste at lozenge doses. Drug interactions include reduced absorption of tetracycline and quinolone antibiotics, bisphosphonates, and penicillamine (separate dosing by at least 2-3 hours). Long-term high-dose intranasal zinc products have been associated with loss of smell - this is product-formulation-specific and not a general oral-supplementation risk.
This summary is informational and not medical advice. Consult a clinician before starting or changing any supplement, especially if you take prescription medications.
Foundations
Foundation of the evidence base
A few studies the field anchors on. Not the full picture, just the starting points.
Most recent Cochrane synthesis on zinc for the common cold, the supplement's most-asked consumer use. Cochrane reviews are the field's gold-standard reference document; this 2024 update is the current anchor for both prevention and treatment claims.
View on PubMedCochrane review that incorporates the historically pivotal AREDS trials, where zinc was a key component of the formulation shown to slow age-related macular degeneration progression. The reference document for zinc's most-established disease-modifying use.
View on PubMedSynthesis of evidence on zinc supplementation in pediatric acute diarrhea and related GI conditions. The WHO and UNICEF recommend zinc supplementation for childhood diarrhea, making this the highest public-health-relevance use of zinc supplementation globally.
View on PubMed
Limitations
What this page doesn't answer
Where the public summary stops and the personalized report begins.
This page summarizes the zinc literature at a general level. It does not address which form (picolinate, gluconate, citrate, carnosine, etc.) is right for your specific goal, what dose to use, timing considerations (especially consequential for cold prevention and treatment), whether your current dietary intake already meets your needs, or how zinc supplementation interacts with copper homeostasis, your medications, or your other supplements. Form and timing are unusually important for zinc compared to most supplements, which is why the personalized report can be especially useful here.
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