Zinc
zinc · zinc picolinate · zinc gluconate
An essential mineral for immunity, promoted for colds and healthy aging.
TipoSupplement / dietary
Il voto risponde a: What does the human evidence support for: Immune function & deficiency correction?
Grado
C
Limitata
Il voto misura la qualità dell'evidenza, non è un consiglio ad assumere o acquistare.
- Classe
- Essential mineral
- Uso principale
- Immune function & deficiency correction
- Forza evidenza
- medium
- Ultima revisione
- 2026-07-01
In sintesi
Correcting deficiency clearly supports immune function, and zinc lozenges can modestly shorten colds — but chronic high-dose supplementation backfires by causing copper deficiency. Fix a shortfall, don't overdose.
Cosa dice l'evidenza
Zinc is essential for immune function, wound healing and hundreds of enzymes, and deficiency (more common in older adults and some diets) genuinely impairs immunity. Zinc lozenges started early can modestly shorten the common cold. Beyond correcting a deficiency, however, more is not better: sustained high-dose zinc induces copper deficiency, which causes its own anaemia and neurological problems. There are no zinc 'longevity' outcome trials. Grade C: valuable for deficiency and short-term cold use, genuinely harmful if chronically overdosed.
Studi chiave
- [1]
Zinc for the common cold · meta-analysis
Modest reduction in cold duration when started early.
Apri su PubMed ↗ - [2]
Zinc, immunity and aging · review
Deficiency impairs immunity, common in older adults.
Apri su PubMed ↗ - [3]
Meccanismo
A cofactor for hundreds of enzymes and transcription factors; central to immune-cell development and function, antioxidant defence and protein synthesis.
Sicurezza
Safe at recommended intakes. The key risk is chronic excess: high-dose zinc blocks copper absorption, causing copper-deficiency anaemia and neurological damage. Long-term supplementation above the upper limit needs copper balance in mind.
Contesto dosaggio
Typical supplemental doses are ~8–15 mg/day; short-term cold lozenges use more for a few days only. Ongoing high-dose (e.g. 50 mg/day) use is where copper depletion becomes a real risk.
Esempi di applicazione
- Taken ~8–15 mg/day to correct a shortfall, or short-term lozenges for colds.
- Not mega-dosed long-term — high zinc causes copper deficiency.
- Balanced with copper if supplementing above the upper limit.
Nota dal campo
Zinc is a two-edged mineral: fix a real deficiency and it helps; megadose it 'for immunity' and you can quietly cause copper deficiency. Grade C, with the overdose warning the cold-remedy marketing skips.