Zinc, RBC Test
An RBC zinc test measures zinc held inside red blood cells. Clinicians sometimes look at it to help evaluate zinc status, since zinc carried within cells offers a different perspective than zinc measured in serum.
About this test
Zinc is a mineral the body uses in a wide range of everyday processes, from supporting the immune system to helping enzymes do their work. A red blood cell zinc test looks at the zinc carried inside those cells rather than the amount circulating in the serum.
The test is done with a routine blood draw at a patient service center. A phlebotomist collects a small sample from a vein, usually in the arm, and sends it to the laboratory.
Who might consider this test?
- Others consider it to follow a situation over time or because a clinician has suggested a closer look.
Test details
| Quest code | 6354 |
|---|---|
| Methodology | Inductively Coupled Plasma/Mass Spectrometry |
| Sample type | 0.5 mL red blood cells |
| Collection | Quest patient service center |
Reference range
9.0-14.7 mg/L
Reference ranges are general guidance. The range printed on your own laboratory report is the one that applies to your result.
Related tests and panels
Quest resources
Additional details
What this test looks at
This test looks at zinc stored inside red blood cells. Since a large portion of the body's zinc is held within cells, the red-cell measurement is one way to reflect that pool. Clinicians sometimes reach for it when they want a view that complements what a serum zinc test shows.
It also helps to remember what this test is not. It does not describe the zinc circulating in the serum, which is a separate measurement answering a slightly different question. The two versions can be read together, and a clinician chooses based on what they are exploring.
How it's often used alongside other markers
RBC zinc is frequently read as part of a wider look at minerals and general nutrition. Depending on what a clinician is exploring, it may be considered alongside serum zinc, copper, or other mineral markers, since these minerals interact and are often reviewed together. Read together, these markers give a fuller sense of the picture than zinc alone.
A clinician weighs the pattern across these results, along with diet, symptoms, and personal history, before drawing any conclusions. No single marker is meant to stand in for the whole story.
Order online and a physician order is included — no doctor's visit and no insurance needed. Your sample is collected at a Quest Diagnostics patient service center.
Laboratory results should always be interpreted by a licensed clinician who knows your health history. This page is information about a test, not medical advice.
Frequently asked questions
What does an RBC zinc test measure?
It measures zinc held inside red blood cells. Because a large share of the body's zinc sits inside cells, this offers a view of the intracellular side of zinc status.
How is RBC zinc different from serum zinc?
Serum zinc reflects the mineral circulating in the blood, while the red blood cell version reflects zinc inside cells. A clinician chooses between them based on the question being explored.
How is the sample collected?
Through a routine blood draw at a patient service center. A phlebotomist takes a small sample from a vein in the arm and sends it to the laboratory for analysis.
Do I need to fast before an RBC zinc test?
No preparation instructions are listed for this test, though people follow any instructions their ordering clinician provides.
Is zinc ever reviewed with copper?
Yes. Zinc and copper interact in the body, so clinicians sometimes look at them together, along with other mineral markers, to see the nutritional picture more fully.
How much does the Zinc RBC test cost?
The cash price at Celio Health is $105. That covers the physician's order and sample collection at a Quest patient service center — no insurance is needed and there's no separate doctor's visit to pay for.