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Mineral

Iron (Ferrous Sulfate)

Also known as: ferrous sulfate, FeSO4, iron(II) sulfate, fe

A
Evidence

An essential mineral critical for oxygen transport, energy production, and immune function. Ferrous sulfate is a highly bioavailable form commonly used in supplemental iron products.

Primary uses

  • Oxygen transport (hemoglobin synthesis)
  • Energy production
  • Immune function
  • Cognitive development and function
  • Iron deficiency anemia prevention and treatment

How it works

  • Core component of hemoglobin and myoglobin
  • Cofactor for cytochrome oxidase and other enzymes
  • Essential for ATP synthesis
  • Required for immune cell function

Dosage

Typical range
8-18 mg daily (recommended dietary allowance); 25-325 mg daily for anemia treatment
Timing
Take on empty stomach 1 hour before or 2 hours after meals for optimal absorption; with food if GI upset occurs
With food
Food reduces absorption by ~40-50%; vitamin C enhances absorption; avoid calcium, tea, coffee which inhibit absorption
Duration
Supplement duration depends on severity of deficiency; treatment typically 3-6 months; maintenance dose for prevention
Special populations
Women 19-50 require 18 mg daily; postmenopausal women and men require 8 mg daily; pregnant women require 27 mg daily; children require 7-11 mg daily based on age

Forms

  • ferrous sulfate· 70/100
  • ferrous bisglycinate· 70/100
  • ferrous fumarate· 70/100
  • ferric citrate· 70/100

Safety

Common side effects

  • Nausea (very common)
  • Constipation or diarrhea
  • Abdominal discomfort
  • Dark-colored stools (expected, not harmful)
  • Headache
  • Metallic taste

Contraindications

  • Hemochromatosis or iron overload disorders
  • Certain anemias (sideroblastic, hemolytic)
  • Active gastrointestinal bleeding without investigation
  • Frequent blood transfusions

Evidence notes

Extensive RCT evidence for iron deficiency anemia treatment and prevention. Strong evidence for efficacy of ferrous salts. Well-established hematologic and biochemical benefits.

Grade A: Multiple well-designed human trials support the main claims.

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Medical disclaimer. This page is educational and does not replace advice from a qualified healthcare provider.