Should Iron Supplementation Be Discontinued?
Yes, discontinue the ferrous sulfate immediately—your patient has replete iron stores with transferrin saturation of 48% and serum iron of 165 µg/dL, both well above therapeutic targets, indicating successful iron repletion and no ongoing deficiency. 1
Interpretation of Current Iron Parameters
Your patient's iron studies demonstrate complete resolution of iron deficiency:
- Transferrin saturation 48%: This exceeds the therapeutic goal of ≥20% and falls within the normal adult range of 20-50%, confirming adequate iron availability for erythropoiesis 1
- Serum iron 165 µg/dL: Elevated above typical reference ranges, indicating abundant circulating iron 1
- TIBC 346 µg/dL: Normal range, suggesting no ongoing iron deficiency state 1
The combination of TSAT 48% with normal TIBC definitively excludes both absolute and functional iron deficiency. 1
Why Continued Supplementation Is Inappropriate
Continuing oral iron when stores are replete offers no clinical benefit and carries potential risks:
- No therapeutic indication: Iron supplementation is indicated only when TSAT <20% or ferritin <30 ng/mL (without inflammation) 1, 2
- Risk of iron overload: Transferrin saturation >50% may indicate early iron accumulation, and values >55% are associated with 60% higher all-cause mortality 3
- Gastrointestinal side effects: Continued unnecessary iron supplementation exposes patients to constipation, nausea, and abdominal discomfort without benefit 4
Clinical Decision Algorithm
Step 1 – Verify iron repletion status:
- TSAT ≥20% AND normal/elevated serum iron = Iron replete → Stop supplementation 1
- TSAT <20% OR ferritin <30 ng/mL = Continue treatment 1, 2
Step 2 – Address the underlying cause:
- Ensure the original cause of iron deficiency (menstrual bleeding, GI blood loss, malabsorption) has been identified and treated 2
- If the underlying cause persists (e.g., ongoing menstrual blood loss), monitor iron parameters every 3-6 months rather than continuing prophylactic supplementation 1
Step 3 – Monitor for recurrence:
- Recheck iron studies (ferritin, TSAT) in 3-6 months after stopping supplementation 1
- Resume treatment only if TSAT falls below 20% or ferritin drops below 30 ng/mL 1, 2
Important Caveats
Do not continue iron "just to be safe"—this common pitfall leads to unnecessary side effects and potential iron accumulation 3, 4. The therapeutic endpoint for oral iron is achieving TSAT ≥20%, which your patient has clearly surpassed 1.
Consider checking serum ferritin if not recently measured, to confirm adequate iron stores (target ≥30-45 ng/mL in non-inflammatory states, ≥100 ng/mL if chronic inflammation present) 1. However, the current TSAT of 48% already confirms sufficient iron availability regardless of ferritin level 1.
Screen for hereditary hemochromatosis if TSAT remains >45% after stopping supplementation for 2-3 months, particularly if there is family history of liver disease or unexplained organ dysfunction 3. While current elevation is likely iatrogenic from supplementation, persistent elevation warrants HFE genetic testing 3.