What is the diagnosis for a patient with low iron levels (25), critical low iron saturation (8), normal Total Iron-Binding Capacity (TIBC) (295), normal Unbound Iron-Binding Capacity (UIBC) (270), and normal serum ferritin (138)?

From the Guidelines

You have iron deficiency with critically low iron saturation, despite normal ferritin levels, and should start oral iron supplementation to improve your iron stores and prevent progression to iron deficiency anemia. Based on the lab results provided, your total iron binding capacity (TIBC) is 295, which is normal, and your unsaturated iron binding capacity (UIBC) is 270, also normal [ 1 ]. However, your serum iron is low at 25, and your iron saturation is critically low at 8%, indicating iron deficiency [ 1 ]. Your ferritin level is normal at 138, which suggests you still have adequate iron stores but are beginning to develop iron deficiency. According to the British Society of Gastroenterology guidelines, serum ferritin is the single most useful marker of iron deficiency anemia (IDA), but other blood tests, such as transferrin saturation, can be helpful if a false-normal ferritin is suspected [ 1 ].

To address your iron deficiency, I recommend starting oral iron supplementation, such as ferrous sulfate 325 mg once or twice daily, taken on an empty stomach with vitamin C (like orange juice) to enhance absorption. It is essential to avoid taking iron with calcium, dairy products, tea, coffee, or antacids as these can reduce absorption. You should take this supplement for 3-6 months and then repeat your iron studies to assess improvement. Common side effects include constipation, nausea, and black stools. To minimize gastrointestinal side effects, you can start with a lower dose and gradually increase it.

It is also crucial to identify and address the underlying cause of your iron deficiency, which could include blood loss (such as heavy menstrual periods, gastrointestinal bleeding), poor dietary intake, or malabsorption issues. Increasing iron-rich foods in your diet (red meat, spinach, beans, fortified cereals) can also help improve your iron levels. A good response to iron therapy, such as a hemoglobin rise ≥10 g/L within a 2-week timeframe, is highly suggestive of absolute iron deficiency, even if the results of iron studies are equivocal [ 1 ].

Key points to consider:

• Start oral iron supplementation to improve iron stores
• Take iron on an empty stomach with vitamin C to enhance absorption
• Avoid taking iron with calcium, dairy products, tea, coffee, or antacids
• Repeat iron studies after 3-6 months to assess improvement
• Identify and address the underlying cause of iron deficiency
• Increase iron-rich foods in your diet to help improve iron levels.

From the Research

Iron Deficiency and Saturation Levels

• The provided lab results show a low iron level (25) and critical low iron saturation (8), but normal ferritin (138) and total iron binding capacity (TIBC) (295) levels 2.
• According to the studies, iron deficiency is defined by a serum ferritin level <30 ng/mL or a transferrin saturation (TSAT) <20% 2, 3.
• The patient's iron saturation level is 8, which is below the normal range, indicating iron deficiency 3.
• However, the patient's ferritin level is 138, which is within the normal range, suggesting that the patient may not have absolute iron deficiency 2, 3.

Diagnosis and Treatment of Iron Deficiency

• The diagnosis of iron deficiency is typically made by measuring serum ferritin and TSAT levels 2, 3.
• The treatment of iron deficiency usually involves oral iron supplementation, such as ferrous sulfate, and addressing the underlying cause of the deficiency 2, 4.
• In some cases, intravenous iron may be necessary, particularly in patients with chronic inflammatory conditions or those who do not respond to oral iron therapy 2, 3.
• The patient's lab results suggest that they may benefit from iron supplementation, but the normal ferritin level may indicate that the deficiency is not severe 2, 3.

Importance of Iron Saturation and Ferritin Levels

• Iron saturation and ferritin levels are important indicators of iron status and can help diagnose iron deficiency 2, 3.
• A low iron saturation level, such as the patient's level of 8, can indicate iron deficiency, even if the ferritin level is normal 3.
• Ferritin levels can be influenced by various factors, including inflammation and liver disease, which can affect the accuracy of iron deficiency diagnosis 2, 5.
• The patient's normal ferritin level may suggest that the iron deficiency is not severe, but the low iron saturation level indicates that iron supplementation may still be necessary 2, 3.