How can I correct low ferritin before surgery?

Understanding Your Lab Results and Preoperative Iron Correction

Your ferritin of 12 μg/L indicates depleted iron stores (iron deficiency), while your serum iron of 216 μg/dL represents circulating iron at that moment—these measure different things, and the low ferritin is what matters for surgery preparation. You need iron supplementation before surgery to reduce surgical complications and transfusion risk.

Why This Lab Pattern Occurs

• Ferritin reflects total body iron stores and is the most sensitive marker for iron deficiency 1
• Your ferritin <15 μg/L confirms true iron deficiency 1
• Serum iron is a snapshot of circulating iron at the time of blood draw and fluctuates throughout the day—it does not reflect your body's iron reserves 1
• This discrepancy is common: you can have normal or even elevated serum iron while your storage compartment (ferritin) is empty 1

Why This Matters for Surgery

Empty iron stores significantly increase surgical risk. Preoperative iron deficiency is associated with:

• Increased risk of requiring blood transfusions during and after surgery 1, 2
• Higher rates of postoperative infections and complications, particularly in abdominal surgery 3
• Longer hospital stays and increased mortality 2, 4
• Even without anemia, iron deficiency impairs tissue oxygenation, immune function, and wound healing 3

Treatment Algorithm for Preoperative Iron Correction

Step 1: Determine Time Until Surgery

If you have 6-8 weeks or more before surgery:

• Start oral iron supplementation with 28-50 mg elemental iron daily 5, 2
• Ferrous gluconate 324 mg tablets contain 38 mg elemental iron—take 1 tablet three to four times daily 6
• Take on an empty stomach with vitamin C (orange juice) to enhance absorption 1
• Avoid tea, coffee, and calcium supplements within 2 hours of iron doses as they block absorption 1

If you have less than 6 weeks before surgery or cannot tolerate oral iron:

• Intravenous iron is strongly preferred for faster correction 1, 2
• IV iron can restore stores within 2-3 weeks versus 6-8 weeks for oral 2
• A single dose of 1000 mg IV ferric carboxymaltose increases hemoglobin by approximately 8 g/L over 8 days 1
• IV iron has minimal serious adverse reactions (38 per million administrations) 1

Step 2: Rule Out Ongoing Blood Loss

• You must be evaluated for sources of chronic blood loss, particularly gastrointestinal bleeding 1
• Ferritin <30 μg/L warrants consideration of gastroenterology referral to exclude malignancy, especially if you are over age 50 1, 7
• In women, assess for heavy menstrual bleeding 5, 7

Step 3: Monitoring and Target Goals

Recheck labs after 8-10 weeks of oral iron or 2-3 weeks after IV iron 5:

• Target ferritin: ≥30 μg/L minimum (some guidelines recommend 50-100 μg/L for surgery) 1, 5
• Target hemoglobin: within normal range (≥130 g/L for surgery) 1
• If no improvement with oral iron, this suggests malabsorption, ongoing blood loss, or inflammation blocking iron uptake 1

Step 4: Address Inflammation if Present

• Check C-reactive protein (CRP) to rule out inflammation 1, 5
• Inflammation can falsely elevate ferritin and block oral iron absorption through hepcidin activation 1
• If CRP is elevated and ferritin is 30-100 μg/L, you may still be iron deficient despite "normal" ferritin 1
• In inflammatory states, IV iron is more effective than oral because it bypasses gut absorption 1, 2

Common Pitfalls to Avoid

• Do not delay surgery evaluation—ideally screen for anemia 4 weeks before elective surgery to allow time for correction 1
• Do not assume normal serum iron means adequate stores—ferritin is the definitive test 1
• Do not continue oral iron if gastrointestinal side effects prevent compliance—switch to IV iron 5, 2
• Do not supplement iron if ferritin is already normal or high (>100 μg/L without inflammation), as this provides no benefit and may cause harm 1, 5

Practical Recommendation

Contact your surgeon immediately to discuss delaying surgery if possible until your iron stores are corrected, as proceeding with ferritin of 12 μg/L substantially increases your surgical risk 1, 3. Request either:

1. IV iron infusion (preferred if surgery is within 6 weeks) 1, 2
2. Oral iron for 6-8 weeks with repeat labs before surgery 5, 2
3. Gastroenterology evaluation to identify and treat any source of chronic blood loss 1, 7