Elemental Iron Content in Ferrous Sulfate 325 mg
Ferrous sulfate 325 mg contains 65 mg of elemental iron. 1
Key Information for Clinical Practice
Standard ferrous sulfate 325 mg tablets provide 65 mg of elemental iron per tablet, which is clearly documented in the NKF-K/DOQI clinical practice guidelines 1
This represents approximately 20% elemental iron content by weight in the ferrous sulfate salt formulation 1
Comparison with Other Iron Preparations
For context, different iron salt formulations contain varying amounts of elemental iron per 325 mg tablet:
- Ferrous sulfate 325 mg = 65 mg elemental iron 1
- Ferrous gluconate 325 mg = 35 mg elemental iron 1
- Ferrous fumarate 325 mg = 108 mg elemental iron 1
Clinical Dosing Implications
For standard iron deficiency treatment, one 325 mg ferrous sulfate tablet daily (65 mg elemental iron) is the recommended starting dose based on British Society of Gastroenterology guidelines 2
To achieve 200 mg elemental iron daily (as recommended for chronic kidney disease patients on erythropoietin), approximately three 325 mg ferrous sulfate tablets would be needed 1
Once-daily dosing of 50-100 mg elemental iron is now preferred over divided doses due to hepcidin regulation that reduces absorption with more frequent dosing 2
Important Prescribing Consideration
- When prescribing, always specify both the total tablet size (325 mg) AND the elemental iron content (65 mg) to avoid confusion, as the notation "325 (65 FE) MG" correctly indicates both values 1