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Iron saturation (serum iron to total iron-binding capacity ratio)

Published: August 9, 2026Updated: August 17, 2026

This test measures how much of your iron is bound to a protein called transferrin, which helps carry iron in your blood. It’s important for assessing iron availability and potential iron deficiency or overload.

Quick summary

["Helps diagnose or monitor iron-related blood disorders."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 17, 2026Editorial policy

Key facts at a glance

LOINC
14801-5
Short code
Iron Satn SFr SerPl
Synonyms
Iron Satn SFr SerPl
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Ref low
60
Ref high
170
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
CPT
83540
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

Why This Test Matters

Iron saturation is a key indicator of your body’s ability to use iron effectively. Low levels may suggest iron deficiency, while high levels could indicate conditions like hemochromatosis or excessive iron intake.

What to Expect Before the Test

No special preparation is needed unless instructed by your healthcare provider. You may have a simple blood draw, usually from a vein in your arm. The process is quick and typically painless.

How the Results Are Used

Your results help doctors diagnose conditions like anemia, iron overload, or other blood disorders. They’re often used alongside other tests, such as ferritin or hemoglobin levels.

Common Conditions Monitored

Iron saturation is commonly checked in people with symptoms of anemia (fatigue, weakness), those with unexplained iron deficiency, or individuals at risk for iron overload (e.g., frequent blood donations).

Reference range

NCBI: Serum Iron Male 65-180; Female 50-170 µg/dLN/A

Specimen: serum

Fasting for 12 hours preferred. Iron supplements should be stopped 24 hours before if possible.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Iron Saturation Ratio

Frequently asked questions

What does an abnormal iron saturation result mean?
An iron saturation below 15–20% often signals iron deficiency, where your body isn’t getting enough iron to function properly. Levels above 80% may indicate iron overload, which can strain your organs over time.
How often should I get this test?
Your doctor will determine how often you need this test based on your health history, symptoms, and other test results. Regular monitoring may be recommended if you have conditions like hemochromatosis or frequent blood transfusions.
Can diet affect iron saturation?
Yes, diet can influence iron levels. Eating foods rich in vitamin C (like citrus fruits) can help your body absorb iron better, while calcium or coffee/tea near meals may reduce absorption. Always follow your doctor’s advice regarding dietary changes.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 17, 2026. · Read our editorial policy