Zinc for Wound Healing
Verdict: Published with Warning
Across 4 PubMed studies, the evidence for Zinc in Wound Healing grades Tier B — preliminary evidence. Effective, but with safety or population caveats.
B 🟡 B Preliminary Evidence Published with Warning
Why this grade7-layer evidence engine
⚖️
Scoring transparency
All scores computed by a 7-layer evidence engine — fully auditableRaw score 0.49
D
C
B
A
S
← counter-evidence / ineffectiveeffective / strong evidence →
Final grade
B · Published with Warning
Confidence
87%
Highly consistent evidence
Evidence level
E1
Cochrane high-quality SR/MA
▸View the full decision path (audit trail)
- compute_raw_score — 加權公式: L2×0.30 + L3×0.25 + L5×0.25 + L11×0.10 + L1×0.10 = 0.487
- tier_from_score — 依分數區間映射至 tier letter
- apply_hec_rules — 高階證據未達主導 (1 positive vs 1 negative)，由 raw_score 決定
- tier_strict_requirement_check — Tier 條件達標，未降階
- detect_disputes — 偵測到 0 個 hard + 0 個 soft dispute
- decide_status — 依 tier + dispute 結果決定 status
PubMed studies (4)L2 · primary research & systematic reviews
Oral zinc for arterial and venous leg ulcers
Finding: Pooling four placebo-controlled venous-ulcer trials showed no statistically significant effect of oral zinc on healing (RR 1.22, 95% CI 0.88 to 1.68); all six included trials were small and at unclear risk of bias.
View on PubMed Systematic review and meta-analysis of the effect of zinc on wound healing
Finding: Zinc was associated with a 41% higher likelihood of ulcer healing at final endpoint (RR 1.41, 95% CI 1.04 to 1.92, p=0.03, I2=0%), but the authors caution that the five included trials are old and of suboptimal quality (total n<200).
View on PubMed Zinc Therapy Is a Reasonable Choice for Patients With Pressure Injuries: A Systematic Review and Meta-Analysis
Finding: Zinc significantly improved pressure-injury healing versus control (RR 1.44, 95% CI 1.01 to 2.06, p=0.043, I2=19.3%), though the pooled set mixed RCTs with non-randomised studies and did not report a total participant count.
View on PubMed The effects of zinc supplementation on wound healing and metabolic status in patients with diabetic foot ulcer: A randomized, double-blind, placebo-controlled trial
Finding: Zinc (50 mg elemental/day for 12 weeks) reduced ulcer length (-1.5 vs -0.9 cm, p=0.02) and width (-1.4 vs -0.8 cm, p=0.02) versus placebo, but the trial now carries a 2024 Expression of Concern (PMID 39164926) that undermines its reliability.
View on PubMed Regulatory & authoritative positionsL4/L5 · FDA / EMA / NIH ODS / Cochrane / Mayo …
L4b EU EFSA
Supportive
contributes to normal function of the immune system source↗
L4c UK NHS
Cautious
You should be able to get all the zinc you need from your daily diet source↗
L4d TW TFDA / 衛福部
Supportive
鋅之每日最高攝食量不得超過30 mg source↗
L4e WHO
Supportive
zinc has been recommended by WHO and UNICEF as the only treatment to be coupled with oral rehydration salts for the treatment of all diarrhoea episodes source↗
L5a NIH Office of Dietary Supplements
Supportive
Zinc is an essential mineral involved in numerous aspects of cellular metabolism source↗
L5b Mayo Clinic
Cautious
Zinc is important for wound healing, and people who have wounds such as skin ulcers and who also have low levels of zinc might benefit from taking a zinc supplement by mouth. source↗
L5c Cleveland Clinic
Supportive
Zinc has a role in protein and collagen synthesis, as well as tissue growth and healing. source↗
L5d Harvard Health
Cautious
The greatest benefit of zinc appears to be in people who are deficient in the mineral and who have severe wounds such as decubitus ulcers or extensive burns. A benefit of zinc supplementation has not been shown in people with skin ulcers who have normal blood levels of zinc. source↗
L5e Specialty Society (condition-mapped)
Cautious
Unless clinical signs of a zinc deficiency are suspected or can be confirmed in clients with wounds, supplementing with high doses of elemental zinc is not recommended. Consuming high levels of supplemental zinc in the range of 100-300mg per day for long periods of time may result in reduced copper and iron status, disruption of collagen cross-linking and may hinder wound healing. source↗