From the Guidelines
For treating iron deficiency anemia, the recommended dosage of ferrous sulfate is 325 mg (65 mg elemental iron) taken orally once daily, and taking 80 mg of vitamin C (ascorbic acid) with each iron dose may improve iron absorption. According to the most recent and highest quality study 1, many formulations of oral iron are available, without substantial evidence that any one product is better than another, and ferrous iron salts are a reasonable choice to start with. The study also suggests that taking iron with 80 mg ascorbic acid on an empty stomach improves iron absorption, and that taking iron more than once a day does not improve absorption but increases side effects.
Some key points to consider when treating iron deficiency anemia include:
- Starting with a lower dose and gradually increasing as needed to minimize side effects such as constipation, nausea, and black stools
- Avoiding taking iron with calcium, dairy, coffee, tea, or high-fiber foods, as these can reduce absorption
- Considering alternative oral preparations or parenteral iron if patients are intolerant or not responding to oral iron, as recommended by 1
- Continuing treatment for 3-6 months after hemoglobin normalizes to replenish iron stores, as suggested by 1 and 1
It's also important to note that vitamin C works by converting iron to its more absorbable ferrous form and creating a soluble complex that prevents iron from binding with absorption inhibitors, as mentioned in 1. However, the evidence supporting vitamin C administration to improve iron absorption is mixed, and further study is needed to clarify the effectiveness of this practice.
From the FDA Drug Label
CONTAINS: Each tablet contains 324 mg of ferrous sulfate, equivalent to 65 mg of elemental iron, providing 362% of the U.S. recommended daily intake (RDI) of iron for adults and children 4 and older.
16 HOW SUPPLIED Ferrous Sulfate Tablets are available as follows: Each tablet contains 324mg of ferrous sulfate, equivalent to 65mg of elemental iron, providing 362% of the U.S. recommended daily intake (RDI) of iron for adults and children 4 and older.
The recommended dosage of ferrous sulfate is 65 mg of elemental iron per tablet, but the FDA drug label does not specify the recommended dosage of vitamin C for treating iron deficiency anemia 2 2.
- The dosage of ferrous sulfate is clearly stated as 65 mg of elemental iron.
- There is no information about vitamin C dosage in the provided drug labels.
From the Research
Recommended Dosage of Ferrous Sulfate and Vitamin C
- The recommended dosage of ferrous sulfate for treating iron deficiency anemia is 60-120 mg of elemental iron per day, given as a single morning dose on alternate days, along with ascorbic acid (vitamin C) 3.
- A study found that providing iron supplements on alternate days and in single doses optimizes iron absorption and may be a preferable dosing regimen 4.
- Another study suggested that a single daily dose of ferrous sulfate (40 mg elemental iron) is as effective as a 3-times-daily dose in treating anemia in infants 5.
- The use of vitamin C (ascorbic acid) can enhance iron absorption, and it is recommended to take it along with ferrous sulfate 3.
Comparison of Ferrous Sulfate with Other Iron Supplements
- A study compared the effect of ferrous sulfate with iron polysaccharide complex on hemoglobin concentration in young children with nutritional iron-deficiency anemia, and found that ferrous sulfate resulted in a greater increase in hemoglobin concentration at 12 weeks 6.
- Another study found that carbonyl iron powder is a safe and effective therapy for iron deficiency anemia, with a daily dose of 1,000 to 3,000 mg of elemental iron 7.
Important Considerations
- The dosage and frequency of ferrous sulfate and vitamin C may vary depending on the individual's specific needs and medical condition.
- It is essential to consult with a healthcare professional before taking any supplements, especially if you have a medical condition or are taking other medications.
- Iron supplements can cause gastrointestinal side effects, and it is crucial to follow the recommended dosage and administration instructions to minimize these effects 3, 4, 6, 7.