How to prepare
A morning fasting sample gives the most consistent result. Avoid eating before your collection where possible.
If you take zinc supplements, check with your practitioner whether to pause them before testing to get an accurate baseline. A healthcare professional will take a blood sample from a vein in your arm.
After the test
Review your result with your GP, nutritionist, or integrative practitioner. If RBC zinc is low, they may explore contributing factors such as dietary patterns, absorption issues, or increased physiological demand, and discuss whether supplementation or dietary change is appropriate.
If you are monitoring zinc status over time as part of an ongoing health plan, this test provides a more precise marker than serum zinc alone.
Your test results will be available in your private dashboard. If there are any urgent issues, we'll let you know so you can follow up with your health professional.
Understanding results
Results are reported as the zinc concentration inside red blood cells, typically in micromoles per litre (umol/L). Reference ranges vary between laboratories; your result report will include the applicable range.
RBC zinc reflects intracellular zinc more accurately than serum zinc because red blood cells accumulate zinc from tissues over their lifespan of around 120 days. A low RBC zinc result, even alongside a normal serum result, may indicate that cellular zinc stores are insufficient.
Your practitioner will interpret this result in the context of your symptoms, dietary intake, health history, and any other relevant investigations.
