Zinc
Measures zinc in your blood, a mineral that supports your immune system, wound healing, and sense of taste and smell.
AI-verified against cited sources. Awaiting expert reviewAlso called ZnLOINC 5763-8
Check your result
Type your result to see where it falls.
Nothing you type here leaves your browser.
What it is
Zinc is an essential mineral that your body uses for immune defense, wound healing, growth and your sense of taste and smell. You get it from foods such as meat, shellfish, beans, nuts and seeds, and from supplements. Most zinc is held inside cells and bone, so the blood holds only a small share. For that reason, a blood zinc level is a rough guide, and it is hard to read on its own.
Why it matters
Blood zinc is the usual way to look for zinc deficiency, which can cause slow wound healing, hair loss, skin rashes, loose stools, frequent infections and a weak sense of taste. Too much zinc from supplements can lower copper, which may lead to anemia and nerve problems. A single result is tricky to read because time of day, infection or inflammation, and low albumin all change it.
If it’s low
A low result can be a sign that you aren't getting or absorbing enough zinc. But blood zinc also drops with inflammation, infection, stress, pregnancy and low albumin, even when your body's zinc stores are fine.
Common causes
- A very limited diet or poor nutrition
- Infection, inflammation or other illness
- Low albumin (blood protein) from liver, kidney or nutrition problems
- Pregnancy
- Oral contraceptives
- Conditions that reduce absorption, such as celiac disease, Crohn's disease or weight-loss surgery
- A blood draw later in the day, since zinc runs lower in the afternoon and evening
What can help
- Ask whether a repeat morning draw would give a clearer answer
- Include zinc-rich foods such as meat, shellfish, beans, nuts and seeds
- Ask whether albumin or an inflammation test (CRP) would help interpret the result
If it’s high
A high result most often comes from zinc supplements or from contamination during blood collection. Taking in too much zinc for a long time can interfere with copper absorption, which can lead to low copper, anemia and nerve problems.
Common causes
- Zinc supplements, lozenges or other products that contain zinc, including some denture adhesives
- Contamination from a tube that wasn't trace-element-free, or from skin
- Fasting before the draw, which can raise zinc slightly
What can help
- Review all products you use that contain zinc with a clinician or pharmacist
- If the result is unexpectedly high and you take no zinc, ask whether a repeat test in a certified metal-free tube makes sense
- Ask whether a copper level should be checked if your zinc intake has been high for a long time
Usual ranges
What labs print as the reference range, by who was tested. Ranges differ a little between labs, so the range on your own report is the one your result is judged against.
The usual range depends on age. Choose an age to see the one that applies.
Children and teens 2 ranges
- 11–1766–110 µg/dL
Source: Mayo Clinic Laboratories
- under 1160–120 µg/dL
Source: Mayo Clinic Laboratories
See Zinc by age and sex, with the U.S. survey numbers where they exist.
If this applies to you
Zinc means a little more for some people. Open the one that fits you.
Had weight-loss surgery
Zinc is absorbed mostly in the first part of the small intestine, which gastric bypass and duodenal switch go around. ASMBS suggests checking zinc at least yearly after these operations, and BOMSS suggests the same after sleeve gastrectomy too.
Vegan or vegetarian
Adult vegetarians tend to have similar or somewhat lower zinc intake and lower blood zinc that is usually still within the usual range, the Academy notes. No health problems from this have been seen in adult vegetarians.
How common is your level?
NHANES describes the US civilian, non-institutionalized population, not a 'healthy' reference group. People with disease, on medication, fasting or not (except fasting-subsample markers), smokers and so on are all included. A percentile says where a value sits among Americans of that sex and age, not whether it is normal.
Use the left and right arrow keys to read each age. Shift moves five years.
Reference data derived from CDC/NCHS National Health and Nutrition Examination Survey (NHANES), cycles 2015-2016. Analysis by bloodtesttracker.com; not endorsed by CDC, NCHS or HHS.
Explore Zinc by age and sex: every percentile as a table, with a download.
What can affect your result
- Time of day: afternoon and evening samples read lower than morning ones
- Fasting state: the IZiNCG cutoffs differ for fasting and non-fasting samples
- Albumin level, infection, inflammation, stress, pregnancy and oral contraceptives
- Zinc supplements and zinc-containing products
- Sample collection: trace-element-free tubes prevent contamination
- Zinc contamination from a tube that isn't trace-element-free, or from skin, can raise the result; ARUP recommends confirming an unexpectedly high result with a second sample in a certified metal-free tube.
- Zinc supplements raise the result. ARUP says patients can ask their physician about pausing supplements for one week before the draw.
- Low albumin, infection, inflammation, stress, pregnancy and oral contraceptives lower serum zinc.
- Fasting may raise the result slightly (ARUP) and morning draws are higher than afternoon or evening draws.
- Mayo Clinic Laboratories advises waiting 96 hours after gadolinium, iodine or barium contrast media before the draw, because they can interfere with this type of metal test.
Morning if possible, in the same fasting state each time. Afternoon and evening draws read lower than morning draws. Serum zinc responds only weakly to diet: in a US national survey it was not related to dietary or supplemental zinc, although ARUP notes that supplements can raise it.
When to talk to a clinician
Talk with a clinician soon about slow-healing wounds, a rash that doesn't go away, hair loss or repeated infections, especially with a low result. If you take zinc regularly and notice numbness, tingling, trouble walking, unusual tiredness or paleness, mention it to a clinician.
Questions you could ask
- Does my diet, pregnancy or any medication affect how I should read this result?
- Do any supplements or products I use contain zinc?
- Should we recheck it in a certified metal-free tube, and is a copper level worth checking?
- Could infection, inflammation or my albumin level explain a low result?
- Should we repeat the test in the morning?
Questions people ask
Why might my doctor want a morning blood draw for zinc?
Zinc runs higher in the morning and falls during the day. In a large US survey, afternoon draws averaged about 10 µg/dL lower and evening draws about 15 µg/dL lower than morning ones. Using the same time of day makes repeat results easier to compare.
Can an infection or inflammation make my zinc look low?
Yes. ARUP notes that blood zinc can drop with infection, inflammation, stress and pregnancy, and it is lower when albumin is low. A low result during an illness may not reflect your body's zinc stores.
How do I convert µg/dL to µmol/L?
Divide µg/dL by 6.54. For example, 80 µg/dL is about 12.2 µmol/L. To go the other way, multiply µmol/L by 6.54.
Show the science and sources
Units
- 1 µg/dL = 1 µg/dL
- 1 µg/dL = 0.1529 µmol/L
- 1 µg/dL = 10 µg/L
- 1 µg/dL = 0.01 mg/L
Is a change real?
Zinc naturally varies about 8.9% from test to test in the same healthy person. Between two results from the same lab, a change of roughly 28% or more is unlikely to be day-to-day noise or lab variation (95% reference change value). Source: Systematic review and meta-analysis of within-subject and between-subject biological variation estimates of serum zinc, copper and selenium (Coskun A et al.).
For clinicians and researchers
Serum or plasma zinc is measured by ICP-MS (Mayo uses triple-quadrupole ICP-MS/MS) in a trace-element-free (royal blue) tube. It is the most widely available zinc biomarker but is insensitive: it is under homeostatic control, falls in the acute-phase response, and depends on albumin. Hennigar et al. (NHANES 2011-2014) found serum zinc was lower in afternoon (-9.7 ug/dL) and evening (-15.3 ug/dL) draws, positively associated with albumin and hemoglobin, and not related to dietary or supplemental zinc; hypoalbuminemia, anemia in females and pregnancy raised the odds of being below the cutoff. IZiNCG cutoffs for low serum zinc (designed for population surveys): for people 10 and older, males below 74 (morning fasting), 70 (morning non-fasting) and 61 ug/dL (afternoon); females below 70, 66 and 59 ug/dL; for children under 10, below 65 (morning) and 57 ug/dL (afternoon), non-fasting. The BRINDA project proposes adjusting plasma zinc for inflammation (CRP and alpha-1-acid glycoprotein). Mayo intervals are age-banded (0-10 years 60-120; 11-17 years 66-110; 18 and older 60-106 ug/dL); ARUP reports 60-120 ug/dL and Quest 60-130 ug/dL for adults. ARUP notes that zinc may be elevated with supplements or fasting and that elevated zinc may interfere with copper absorption.
LOINC 5763-8 (primary), 14955-9. Specimen: serum-or-plasma.
Sources
- Zinc, Serum - Test ID ZN_S (Mayo Clinic Laboratories Extended Catalog), Mayo Clinic Laboratories
- Zinc, Serum or Plasma (test 0020097), ARUP Laboratories
- Serum Zinc Concentrations in the US Population Are Related to Sex, Age, and Time of Blood Draw but Not Dietary or Supplemental Zinc, The Journal of Nutrition (2018)
- Adjusting plasma or serum zinc concentrations for inflammation: Biomarkers Reflecting Inflammation and Nutritional Determinants of Anemia (BRINDA) project, The American Journal of Clinical Nutrition (2020)
- Zinc deficiency is highly prevalent and spatially dependent over short distances in Ethiopia, Scientific Reports (2021)
- A Hematologic Twist: Zinc-Induced Copper Deficiency Mimicking Myelodysplastic Syndrome, Cureus (2025)
- Zinc (Quest Diagnostics test, adult interval as listed by Fullscript), Fullscript (listing Quest Diagnostics test data)
AI-verified against cited sources. Awaiting expert review. Last reviewed 2026-10-03. How we build and check these pages.