IronReported in µg/dLUnsaturated iron-binding capacity (UIBC)
How much additional iron the blood’s transport protein could still carry. High UIBC means a lot of empty carrying capacity.
What it measures
Transferrin is the protein that ferries iron. UIBC is the portion of that carrying capacity that is not yet occupied. When the body is short on iron, the liver makes more transferrin and the empty seats increase, so UIBC rises. When iron is plentiful, the seats fill and UIBC falls. Total iron-binding capacity is roughly serum iron plus UIBC. This panel reports the two ingredients separately.
Why it is on the panel
UIBC is what turns a lone iron level into a pattern. Iron by itself swings with the time of day and with what you ate. The binding capacity moves more slowly and tells you whether the body is trying to capture more iron.
How to read it
Read UIBC with the iron result and with hemoglobin, MCV, and RDW. Low iron, high UIBC, low hemoglobin, low MCV: iron deficiency until proven otherwise. High iron, low UIBC: think about overload, supplements, or a liver that is releasing stored iron. Typical iron and typical UIBC, with a low hemoglobin: look beyond iron, including chronic disease and B12 or folate.
When it runs higher
Iron deficiency is the classic reason UIBC climbs. Pregnancy and estrogen can raise transferrin as well. A high UIBC with a still-normal hemoglobin can be an early iron deficit, before anemia arrives.
When it runs lower
Iron overload, inflammation, chronic disease, and malnutrition can lower UIBC. Inflammation pushes the body to hide iron and to make less transferrin, so the pattern looks almost opposite to simple deficiency. That is a common source of confusion, and it is why one number is never the whole story.
Same group
Other Iron tests
How to use this page
This page explains what the measurement is for. It is educational. Your Healiam report includes the reference interval for your age and sex, and a clinician reads that result with your history, medicines, and the rest of the panel. Talk with a clinician before changing diet, supplements, or treatment because of a number on a report.
UIBC
UIBC is part of the full panel.
No referral or insurance required.
One preventive draw covers this measurement and the rest of the Healiam panel. CLIA-certified results come back in days.