Skip to main content

Zinc

Zinc supports enzyme activity, gene regulation, immune function, and tissue repair. Evidence is insufficient to determine whether extra zinc improves graft take, fistula closure, or flap survival.[1][2][7]

Physiology and Dietary Requirements​

Zinc has catalytic, structural, and regulatory roles. Zinc fingers stabilize many proteins involved in transcription. Most body zinc is in muscle and bone. Absorption and gastrointestinal losses regulate balance; serum zinc represents a small, rapidly changing compartment.[2]

For adults, the US RDA is 11 mg/day for men and 8 mg/day for women, increasing to 11 mg in pregnancy and 12 mg during lactation. The adult tolerable upper intake level is 40 mg/day, excluding higher-dose treatment under medical supervision. Meat, shellfish, dairy, legumes, nuts, and fortified foods contribute zinc; phytate reduces absorption from plant foods. A plant-based diet calls for appropriate dietary planning, not a diagnosis of deficiency.[1]

Prescribe elemental zinc. The mass of zinc sulfate, gluconate, acetate, or oxide is not the mass of zinc it contains. Check the product's elemental content before converting doses.[1][6]

Assessment of Zinc Status​

Interpret serum or plasma zinc alongside diet, symptoms, inflammation, albumin, and the collection conditions. There is no single sensitive test that reliably diagnoses every individual with mild deficiency.[2]

The BOND review gives the following cutoffs for population risk of deficiency; the female column applies outside pregnancy, which requires separate interpretation.[24] They do not classify severity in an individual patient:[2]

Sample conditionsFemales ≥10 yearsMales ≥10 years
Morning, fasting<70 μg/dL<74 μg/dL
Morning, nonfasting<66 μg/dL<70 μg/dL
Afternoon<59 μg/dL<61 μg/dL
  • A low result may reflect redistribution or reduced binding. Inflammation, hypoalbuminemia, pregnancy, recent meals, and time of day affect the measurement. Use trace-element collection procedures and the laboratory's reference interval.[2][3]
  • Wessells et al. evaluated a 50 μg/dL plasma-zinc cutoff for clinical signs in adults undergoing severe dietary restriction and people with acrodermatitis enteropathica.[4]
  • NHANES 2011–2014 found no association with reported dietary or supplemental intake in its adjusted cross-sectional analysis. The updated systematic review of intervention studies confirmed a response, with substantial heterogeneity.[3][5]
  • Hair zinc, nonspecific enzyme activity, and unvalidated commercial mineral panels should not replace clinical assessment. Growth response is a functional indicator used in children, not an adult preoperative diagnostic test.[2]

Deficiency: Who Needs Assessment?​

Causes to consider include inadequate intake, alcohol use disorder, malabsorption, chronic diarrhea, short bowel, bariatric surgery, high gastrointestinal losses, and chronic liver disease. Poor appetite or taste, dermatitis, alopecia, delayed healing, and impaired growth can occur but are nonspecific. Severity is not assigned from a symptom list, and zinc deficiency is not diagnosed from hyperammonemia alone.[2][6][10]

Acrodermatitis enteropathica is an inherited SLC39A4-related absorption disorder, classically associated with acral or periorificial dermatitis, alopecia, and diarrhea. Acquired deficiency can resemble it. Suspected inherited disease needs specialist assessment and sustained replacement with monitoring; a short general nutritional course may be inadequate.[2]

After Bariatric Surgery​

ASMBS recommends zinc screening at least annually after RYGB or BPD/DS (Grade C, BEL 3) and zinc evaluation after any bariatric procedure for symptoms suggestive of iron-deficiency anemia despite negative iron-deficiency screening (Grade C, BEL 3) or chronic diarrhea (Grade D, BEL 4).[6] The table below retains the ASMBS 2016 routine supplement ranges.[6] The 2025 OMA statement lists annual serum zinc assessment after SG, RYGB, SADI-S, and BPD/DS, with 16–22 mg/day in routine supplements for these procedures; coordinate zinc and copper changes with the bariatric team.[22]

ProcedureElemental zinc in the routine daily supplement
Sleeve gastrectomy or gastric band8–11 mg[6]
RYGB8–22 mg[6]
BPD/DS16–22 mg[6]

Balance supplementation with copper; ASMBS suggests approximately 8–15 mg zinc per 1 mg copper. This is a prevention framework, not a substitute for treating established copper deficiency. ASMBS found insufficient evidence for a universal zinc repletion dose and cautioned against its older 60 mg twice-daily regimen. Choose treatment and reassessment according to the cause, degree of deficiency, and copper status.[6]

GLP-1 therapy alone is not an established indication for routine zinc testing before every operation. Assess persistent poor intake, vomiting, weight loss, malabsorption, and the planned procedure as part of a broader nutritional assessment.

Wounds and Reconstructive Surgery​

Correct nutritional deficiency as part of comprehensive care, including adequate energy and protein, perfusion, infection control, pressure relief, and management of the wound's cause. Avoid presenting zinc as a proven standalone healing treatment.[7]

The 2024 Cochrane review found very uncertain evidence for zinc supplementation in pressure-ulcer healing. Its zinc-alone evidence came from two small older trials; evidence for combinations of protein, arginine, zinc, and antioxidants was also uncertain. A change in a collagen marker in a multinutrient trial cannot identify zinc's effect or establish fewer clinical wound failures.[7]

For incontinence-associated skin exposure in acute care, zinc oxide paste or cream can protect perineal skin from urine or stool when applied according to product instructions.[27] An Unna boot is a leg-ulcer dressing and compression approach and is not a standard pelvic or intravaginal wound treatment.[8]

For peristomal skin beneath an adhesive appliance, address fit and leakage first. WOCN guidance uses appropriately applied barrier powder, with optional alcohol-free barrier film, for moist skin injury. Zinc cream is not substituted beneath the wafer by default; products must be compatible with the appliance, and an ostomy nurse should be involved.[9]

Other Established or Studied Uses​

Liver Disease and Hepatic Encephalopathy​

For nutritional supplementation in liver disease, the 2025 ACG guideline advises considering zinc when hypozincemia or compatible deficiency findings are present and, if given, using no more than 50 mg elemental zinc daily with a meal to limit nausea and copper deficiency.[10] Low serum zinc in cirrhosis is also influenced by albumin and disease severity.[10]

In the 2019 meta-analysis, four trials entered quantitative synthesis; the number-connection-test comparison of zinc plus lactulose versus lactulose alone used three trials, 227 patients. Performance improved, but heterogeneity was high, one trial included other antioxidants, and pooled ammonia and digit-symbol results were not significantly different. Hospitalization outcomes and adverse events were not reported. The small 69-patient Zinc-MHE trial subsequently supported psychometric benefit over 12 weeks. The 2019 synthesis and Zinc-MHE trial report psychometric outcomes in cirrhotic patients.[11][12] The 2026 ACG guideline conditionally suggests adjunctive zinc for patients with overt hepatic encephalopathy, low blood zinc, and persistent symptoms despite lactulose and rifaximin (very-low-certainty evidence).[26]

Wilson Disease​

Zinc induces intestinal metallothionein and reduces copper absorption. AASLD guidance permits zinc for selected asymptomatic patients and maintenance therapy; EASL-ERN 2025 strongly recommends chelators as the primary choice for significant hepatic disease (LoE 3).[13][14]

The US GALZIN indication is maintenance after initial chelation; the usual adult dose is 50 mg elemental zinc three times daily, taken at least one hour before or two to three hours after meals. Pediatric, pregnancy, and combination regimens require specialist selection and copper-balance monitoring. If copper-deficiency symptoms develop during GALZIN treatment, the US label directs interruption of zinc and measurement of zinc, 24-hour urinary copper, and non-ceruloplasmin-bound copper; subsequent monitoring guides resumption.[15] The US GALZIN label reports postmarketing gastric ulcers with long-term zinc-acetate use, including perforation with peritonitis, and directs discontinuation if signs or symptoms of gastric ulcer develop.[15] Do not transplant a dose from a different country's product label into a US prescription.[15]

For intermediate AMD or advanced AMD in one eye, AREDS antioxidants plus zinc reduced progression to advanced disease by approximately 25% over five years.[16] The usual AREDS2 formula contains 80 mg elemental zinc and 2 mg copper; it is not general AMD prevention.[16] In AREDS, genitourinary hospitalizations occurred in 134/1,783 zinc-assigned participants (7.5%) versus 90/1,838 without zinc (4.9%) over an average 6.3 years of follow-up.[25] AREDS2 did not detect a difference between 25 and 80 mg zinc.[16] Lutein and zeaxanthin replaced beta-carotene, particularly relevant to current or former smokers.[16][17]

Common Cold and Childhood Diarrhea​

  • Common cold: the 2024 Cochrane review found little or no preventive effect. Treatment may shorten symptoms by about 2.4 days, with low-certainty, highly heterogeneous evidence and more nonserious adverse effects. This does not justify indefinite high-dose supplementation.[18]
  • Childhood diarrhea: WHO's 2024 guideline strongly recommends adjunctive oral zinc for acute watery or persistent diarrhea in children up to 10 years (moderate-certainty evidence); it conditionally suggests 5 mg daily for up to 14 days (low-certainty evidence).[19] This updates the older age-specific regimen of 20 mg/day for children aged six months or older and 10 mg/day for infants younger than six months; zinc accompanies appropriate rehydration.[19][23]

Excess Zinc, Copper Deficiency, and Interactions​

Sustained supplemental zinc can inhibit copper absorption. 50 mg/day or more for weeks can be problematic;[1] 100–300 mg/day is not a threshold below which copper deficiency is excluded.[21] Gastrointestinal intolerance may occur earlier.[1][21]

With unexplained cytopenias, sensory ataxia, paresthesias, or myelopathy, ask about supplements and zinc-containing denture adhesive. Check copper, ceruloplasmin, zinc, and B12 as appropriate. Copper-deficiency myelopathy can resemble B12 deficiency, but urinary symptoms occur in a minority, and an elevated zinc concentration is not required to diagnose copper deficiency. Stop an excessive nonessential zinc source and arrange copper replacement; severe deficiency or neurologic disease may need parenteral treatment. Hematologic recovery is generally better than neurologic recovery.[20][21]

Zinc can reduce absorption of quinolone and tetracycline antibiotics and penicillamine. Follow the particular drug's labeling for separation; Wilson disease regimens need specialist coordination rather than a generic interaction interval. Review total zinc from all products, including a prescribed AREDS formulation, before adding another supplement.[1][13][16]

See Also​

References​

1. NIH Office of Dietary Supplements. Zinc: Health Professional Fact Sheet. Updated January 2026.

2. King JC, Brown KH, Gibson RS, et al. Biomarkers of Nutrition for Development (BOND)—Zinc Review. J Nutr. 2016;146:858S–885S. doi:10.3945/jn.115.220079

3. Hennigar SR, Lieberman HR, Fulgoni VL, McClung JP. Serum zinc concentrations in the US population are related to sex, age, and time of blood draw but not dietary or supplemental zinc. J Nutr. 2018;148:1341–1351. doi:10.1093/jn/nxy105

4. Wessells KR, King JC, Brown KH. Development of a plasma zinc concentration cutoff to identify individuals with severe zinc deficiency. J Nutr. 2014;144:1204–1210. doi:10.3945/jn.114.191585

5. Ceballos-Rasgado M, Brazier AKM, Gupta S, et al. Methods of assessment of zinc status in humans: an updated review and meta-analysis. Nutr Rev. 2025;83. doi:10.1093/nutrit/nuae072

6. Parrott J, Frank L, Rabena R, et al. ASMBS Integrated Health Nutritional Guidelines for the Surgical Weight Loss Patient—2016 Update: Micronutrients. Surg Obes Relat Dis. 2017;13:727–741. doi:10.1016/j.soard.2016.12.018

7. Langer G, Wan CS, Fink A, Schwingshackl L, Schoberer D. Nutritional interventions for preventing and treating pressure ulcers. Cochrane Database Syst Rev. 2024;2:CD003216. doi:10.1002/14651858.CD003216.pub3

8. Lansdown AB, Mirastschijski U, Stubbs N, et al. Zinc in wound healing: theoretical, experimental, and clinical aspects. Wound Repair Regen. 2007;15:2–16. doi:10.1111/j.1524-475X.2006.00179.x

9. Wound, Ostomy, and Continence Nurses Society. Peristomal Skin Assessment Guide. Accessed September 2026.

10. Singal AK, Wong RJ, Dasarathy S, et al. ACG Clinical Guideline: Malnutrition and Nutritional Recommendations in Liver Disease. Am J Gastroenterol. 2025;120:950–972. doi:10.14309/ajg.0000000000003379

11. Shen YC, Chang YH, Fang CJ, Lin YS. Zinc supplementation in patients with cirrhosis and hepatic encephalopathy: a systematic review and meta-analysis. Nutr J. 2019;18:34. doi:10.1186/s12937-019-0461-3

12. Janyajirawong R, Vilaichone RK, Sethasine S. Efficacy of zinc supplement in minimal hepatic encephalopathy: Zinc-MHE trial. Asian Pac J Cancer Prev. 2021;22:2879–2887. doi:10.31557/APJCP.2021.22.9.2879

13. Schilsky ML, Roberts EA, Bronstein JM, et al. A multidisciplinary approach to the diagnosis and management of Wilson disease: 2022 AASLD practice guidance. Hepatology. doi:10.1002/hep.32801

14. European Association for the Study of the Liver. EASL-ERN Clinical Practice Guidelines on Wilson's disease. J Hepatol. 2025. doi:10.1016/j.jhep.2024.11.007

15. GALZIN (zinc acetate). US prescribing information.

16. National Eye Institute. AREDS/AREDS2 clinical trials: design and findings. Updated October 2025.

17. Evans JR, Lawrenson JG. Antioxidant vitamin and mineral supplements for slowing the progression of age-related macular degeneration. Cochrane Database Syst Rev. 2023;9:CD000254. doi:10.1002/14651858.CD000254.pub5

18. Nault D, Machingo TA, Shipper AG, et al. Zinc for prevention and treatment of the common cold. Cochrane Database Syst Rev. 2024;5:CD014914. doi:10.1002/14651858.CD014914.pub2

19. World Health Organization. Guideline on management of pneumonia and diarrhoea in children up to 10 years of age. 2024. Recommendations 3a–3c for diarrhea.

20. Jaiser SR, Winston GP. Copper deficiency myelopathy. J Neurol. 2010;257:869–881. doi:10.1007/s00415-010-5511-x

21. Dutta A, Chaudhary V, Kumari S, et al. Zinc-induced hematologic toxicities: a systematic review of descriptive studies. Biol Trace Elem Res. 2026. doi:10.1007/s12011-026-05136-z

22. Benson-Davies S, Frederiksen K, Patel R. "Bariatric nutrition and evaluation of the metabolic surgical patient: Update to the 2022 Obesity Medicine Association (OMA) bariatric surgery, gastrointestinal hormones, and the microbiome clinical practice statement (CPS)." Obes Pillars. 2025;13:100154. doi:10.1016/j.obpill.2024.100154

23. World Health Organization and UNICEF. "Clinical Management of Acute Diarrhoea: A WHO/UNICEF Joint Statement." 2004. Joint statement PDF.

24. Hotz C, Peerson JM, Brown KH. "Suggested lower cutoffs of serum zinc concentrations for assessing zinc status: reanalysis of the second National Health and Nutrition Examination Survey data (1976–1980)." Am J Clin Nutr. 2003;78(4):756–764. doi:10.1093/ajcn/78.4.756

25. Age-Related Eye Disease Study Research Group. "A randomized, placebo-controlled, clinical trial of high-dose supplementation with vitamins C and E, beta carotene, and zinc for age-related macular degeneration and vision loss: AREDS report no. 8." Arch Ophthalmol. 2001;119(10):1417–1436. doi:10.1001/archopht.119.10.1417

26. Bajaj JS, Jakab SS, Jesudian AB, et al. "ACG Clinical Guideline: Hepatic Encephalopathy." Am J Gastroenterol. 2026;121(3):588–618. doi:10.14309/ajg.0000000000003899

27. Wound, Ostomy, and Continence Nurses Society. IPCaRe: Skin Care Guidelines. Accessed October 2026.