What is the recommended dose of iron supplements (Ferrous sulfate) for iron deficiency?

From the Guidelines

The initial treatment of iron deficiency anaemia (IDA) in adults should be with one tablet per day of ferrous sulphate, fumarate or gluconate. This recommendation is based on the British Society of Gastroenterology guidelines for the management of IDA in adults, as stated in the 2021 study published in the journal Gut 1.

Key Considerations

• The dose can be adjusted if not tolerated, with options including a reduced dose of one tablet every other day, alternative oral preparations, or parenteral iron.
• It is essential to consider the evidence quality, which is medium, and the consensus, which is 92%, with a strong statement strength.

Treatment Approach

• The treatment approach should prioritize the patient's tolerance and response to the initial dose, with adjustments made as needed to minimize side effects and optimize absorption.
• The use of ferrous sulphate, fumarate, or gluconate is recommended due to their effectiveness and relatively low risk of adverse effects.

Monitoring and Duration

• Treatment typically continues for 3-6 months after blood counts normalize to replenish iron stores.
• Regular monitoring of blood counts and iron levels is crucial to assess the effectiveness of treatment and adjust the dose or formulation as needed.

From the FDA Drug Label

DIRECTIONS FOR USE: Do not crush or chew tablets. Adult Serving Size: 1 tablet two to three times daily. 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 iron supplement dose for adults is 1 tablet two to three times daily, with each tablet containing 65mg of elemental iron 2 2.

• The dose for children should be determined by consulting a physician.
• The elemental iron content in each tablet is 65mg.

From the Research

Iron Supplement Dose

The optimal dose of iron supplements can vary depending on the individual's condition and the severity of iron deficiency.

• Studies have shown that oral iron doses of 60-120 mg per day can be effective in treating iron deficiency anemia 3.
• However, the frequency of dosing is also important, with alternate-day schedules potentially increasing iron absorption and reducing side effects 3.
• For children and adolescents, low-dose iron supplementation (<5 mg/kg/day) combined with treatment durations of either less than 3 months or more than 6 months may be optimal for improving hemoglobin levels 4.
• In some cases, higher doses of iron may be necessary, such as 150-200 mg per day, but these doses may also increase the risk of gastrointestinal side effects 5, 3.

Factors Affecting Iron Absorption

Several factors can affect iron absorption, including:

• The type of iron supplement used, with ferrous sulfate and iron bis-glycinate chelate being commonly used options 6, 7.
• The timing of dosing, with morning doses potentially increasing iron absorption 3.
• The presence of other nutrients, such as ascorbic acid, which can enhance iron absorption 3.
• The individual's overall health status, with certain conditions potentially affecting iron absorption 5, 4.

Special Considerations

Certain populations may require special consideration when it comes to iron supplementation, including:

• Pregnant women, who may require higher doses of iron due to increased iron requirements 5.
• Children and adolescents, who may require lower doses of iron and closer monitoring of iron status 4.
• Individuals with underlying medical conditions, who may require adjusted dosing regimens or closer monitoring of iron status 5, 4.