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Iron Supplement (Oral) Pregnancy: A

Ferrous Sulphate

Brand names: Feospan, Ironorm

Adult dose

Dose: 200 mg two to three times daily (prophylaxis: 200 mg once daily)
Route: oral
Frequency: two to three times daily
Max: 600 mg/day
Take on empty stomach for best absorption; if intolerant, take with food (reduces absorption by ~50%); give with vitamin C to improve absorption; expect black stools

Paediatric dose

Dose: 1 mg/kg
Route: oral
Frequency: Three times daily (total 3 mg/kg/day elemental iron in 2–3 divided doses)
Max: 200 mg per dose (= 65 mg elemental iron)
Concentration: ferrous sulphate 150 mg/5 mL syrup mg/ml
BNFc paediatric iron-deficiency anaemia: 3 mg/kg/day elemental iron in 2–3 divided doses (each ferrous sulphate 200 mg tablet = 65 mg elemental iron). Practical age bands: 1–5 years 120 mg BD ferrous sulphate; 6–12 years 200 mg BD; 12+ years 200 mg 2–3 times daily. Take on empty stomach for absorption; concurrent vitamin C improves absorption. Expect black stools.

Dose adjustments

Renal

No dose adjustment required

Hepatic

No dose adjustment required

Paediatric weight-based calculator

BNFc paediatric iron-deficiency anaemia: 3 mg/kg/day elemental iron in 2–3 divided doses (each ferrous sulphate 200 mg tablet = 65 mg elemental iron). Practical age bands: 1–5 years 120 mg BD ferrous sulphate; 6–12 years 200 mg BD; 12+ years 200 mg 2–3 times daily. Take on empty stomach for absorption; concurrent vitamin C improves absorption. Expect black stools.

Clinical pearls

  • Target Hb rise 10–20 g/L per 2 weeks — if no response, review diagnosis and compliance
  • Continue 3 months after normalisation of Hb to replenish stores
  • Each ferrous sulphate 200 mg tablet contains 65 mg elemental iron — highest per-tablet iron of common salts

Contraindications

  • Haemochromatosis
  • Haemosiderosis
  • Repeated blood transfusions
  • Anaemia NOT due to iron deficiency

Side effects

  • Nausea
  • Vomiting
  • Constipation
  • Diarrhoea
  • Black stools
  • Abdominal pain
  • Tooth staining (liquid)

Interactions

  • Antacids (reduce absorption)
  • Tetracyclines (mutual absorption impairment)
  • Fluoroquinolones (reduce absorption)
  • Levothyroxine (reduce absorption — give 2h apart)

Monitoring

  • FBC every 2–4 weeks initially
  • Reticulocyte count
  • Serum ferritin at 3 months

Reference: BNFc; BNF 86; NICE NG24. Verify against your local formulary and the latest BNF before prescribing.

Related

Curated clinical cross-links plus same-class fallbacks.

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