Choosing an Iron Salt — Sulfate, Fumarate, or Gluconate
Placeholder: salts differ mainly in elemental iron content per tablet.
- 20%: Ferrous sulfate elemental (placeholder value)
- 33%: Ferrous fumarate elemental (placeholder value)
- 12%: Ferrous gluconate elemental (placeholder value)
- 300 mg: Typical tablet strength (placeholder value)
Why formulation matters
Placeholder: salt choice changes elemental iron delivered per pill.
Clinical preference patterns
Placeholder: gluconate often chosen for gentler GI profile.
Dose and Schedule Setup — Splitting the Daily Iron Load
Placeholder: larger single doses increase side effects, not always absorption.
- 60–120 mg: Common daily dose (placeholder value)
- ~325 mg salt: Max single dose (placeholder value)
- emerging option: Alternate-day dosing (placeholder value)
- 1–3×/day: Divided doses (placeholder value)
Frequency vs. tolerability
Placeholder: splitting dose can reduce peak GI irritation.
Alternate-day strategy
Placeholder: less frequent dosing may raise absorption fraction.
GI Absorption — Duodenal Uptake via DMT1
Placeholder: ferrous iron is absorbed mainly in the duodenum.
- Duodenum: Absorption site (placeholder value)
- DMT1: Key transporter (placeholder value)
- 10–35%: Typical fraction absorbed (placeholder value)
- downregulates uptake: Hepcidin regulation (placeholder value)
Transporter saturation
Placeholder: higher doses saturate DMT1, lowering efficiency.
Hepcidin feedback
Placeholder: iron stores signal hepcidin to blunt absorption.
GI Side Effect Buildup — Nausea, Cramping, and Constipation
Placeholder: unabsorbed iron irritates the gut lining.
- dose-dependent: Nausea incidence (placeholder value)
- common at high dose: Constipation incidence (placeholder value)
- benign side effect: Dark stool (placeholder value)
- up to ~20%: Discontinuation rate (placeholder value)
Mechanism of GI irritation
Placeholder: free luminal iron generates reactive oxidative stress.
Mitigation strategies
Placeholder: lower dose, food, or alternate-day schedule helps.
Hemoglobin Response Over Weeks of Supplementation
Placeholder: hemoglobin rises gradually as absorbed iron fuels erythropoiesis.
- ~0.1–0.2 g/dL/wk: Expected rise (placeholder value)
- peaks ~7–10 days: Reticulocyte response (placeholder value)
- 3–6 months: Typical course length (placeholder value)
- after Hgb normalizes: Repletion of stores (placeholder value)
Erythropoiesis timeline
Placeholder: marrow response lags several days behind absorption.
Monitoring response
Placeholder: recheck hemoglobin after several weeks of therapy.
Placeholder: inadequate rise after a month prompts re-evaluation.