What is the significance of low serum iron (Iron) levels of 5 and low transferrin saturation of 8?

Medical Advisory BoardAll articles are reviewed for accuracy by our Medical Advisory Board
Educational purpose only • Exercise caution as content is pending human review
Article Review Status
Submitted
Under Review
Approved

Last updated: May 1, 2025View editorial policy

Personalize

Help us tailor your experience

Which best describes you? Your choice helps us use language that's most understandable for you.

From the Guidelines

The patient's iron level of 5 and transferrin saturation of 8% indicate iron deficiency anemia, and I strongly recommend initiating iron therapy to improve morbidity, mortality, and quality of life. According to the British Society of Gastroenterology guidelines for the management of iron deficiency anemia in adults 1, serum ferritin is the most useful marker of iron deficiency anemia (IDA), but other blood tests like transferrin saturation can be helpful if a false-normal ferritin is suspected.

Key Points to Consider

  • The patient's low iron level and transferrin saturation suggest depleted iron stores, which can cause fatigue, weakness, reduced exercise capacity, and impaired cognitive function.
  • Iron deficiency anemia can be confirmed by a good response to iron therapy, with a hemoglobin rise of ≥10 g/L within a 2-week timeframe 1.
  • The guidelines recommend that iron deficiency should be confirmed by iron studies prior to investigation, and that a good response to iron therapy is highly suggestive of absolute iron deficiency, even if the results of iron studies are equivocal 1.

Treatment Recommendations

  • I recommend starting oral iron supplementation with ferrous sulfate 325 mg (containing 65 mg elemental iron) taken once or twice daily on an empty stomach.
  • Take it with vitamin C (such as orange juice) to enhance absorption, and avoid taking it with calcium, dairy, coffee, tea, or antacids which can reduce absorption.
  • Treatment should continue for at least 3-6 months to replenish iron stores completely, even after hemoglobin normalizes.
  • Monitor for side effects like constipation, nausea, or black stools, and consider alternative iron supplements like ferrous gluconate or iron polysaccharide if side effects are intolerable.

Follow-up and Monitoring

  • Follow up with repeat blood tests in 4-8 weeks to ensure improvement in iron levels and transferrin saturation, which should increase to at least 20-50% with successful treatment.
  • Regular monitoring of hemoglobin levels and iron studies can help assess the effectiveness of treatment and prevent complications associated with iron deficiency anemia.

From the FDA Drug Label

Eligibility for this study included chronic hemodialysis patients with a hemoglobin below 10 g/dL (or hematocrit at or below 32%) and either serum ferritin below 100 ng/mL or transferrin saturation below 18%. The patient's iron level is 5 and transferrin saturation is 8, which is below the threshold of 18% for transferrin saturation.

  • The patient's transferrin saturation is 8%, which is lower than the threshold.
  • The patient's iron level is 5, but the units are not specified in the question. Based on the information provided, it appears that the patient may be eligible for the study, but the units of the iron level are not specified. 2

From the Research

Iron Levels and Transferrin Saturation

  • Iron level of 5 and transferrin saturation of 8 may indicate iron deficiency, as iron deficiency is characterized by low iron stores and decreased transferrin saturation 3.
  • Transferrin saturation is a measure of the amount of iron bound to transferrin, a protein that transports iron in the blood, and a saturation of 8% may be considered low 4.
  • Low iron stores can lead to decreased hemoglobin production, resulting in iron deficiency anemia, although hemoglobin levels may not always be affected 3, 4.

Treatment and Supplementation

  • Ferrous sulfate is a commonly used iron supplement for the treatment of iron deficiency anemia, but it can have gastrointestinal side effects 4, 5.
  • Lactoferrin supplementation has been shown to have better effects on serum iron, ferritin, and hemoglobin concentration compared to ferrous sulfate, with fewer side effects 4.
  • The choice of iron supplement and treatment strategy may depend on individual factors, such as the severity of iron deficiency and the presence of gastrointestinal side effects 5.

Unrelated Studies

  • Some studies, such as the one on the total condylar knee prosthesis, are not relevant to iron levels and transferrin saturation 6.

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

Have a follow-up question?

Our Medical A.I. is used by practicing medical doctors at top research institutions around the world. Ask any follow up question and get world-class guideline-backed answers instantly.