Quick summary

Ferrous fumarate is an iron salt commonly used as a dietary supplement to provide iron, an essential mineral important for oxygen transport and numerous metabolic processes in the human body.

What is it?

Ferrous fumarate is a compound consisting of iron in the ferrous (Fe2+) form combined with fumaric acid. It is one of several iron salts used in supplements and fortified foods to improve iron intake. Iron is a vital mineral playing critical roles in various physiological functions, mainly related to oxygen transport and cellular metabolism.

Main functions in the body

  • Component of hemoglobin and myoglobin, aiding oxygen transport in blood and muscle
  • Essential for cellular energy metabolism
  • Supports normal cognitive function and immune system function

Recommended intake and upper limit

The recommended dietary allowances (RDA) for iron vary by age, sex, and physiological status as established by authoritative bodies such as the NIH Office of Dietary Supplements. Tolerable upper intake levels (UL) have been set to help avoid iron toxicity from excessive intake.

For specific intake recommendations, it is advisable to consult national guidelines or health professionals tailored to individual needs.

Source: NIH Office of Dietary Supplements Iron Fact Sheet

Best food sources

  • Red meat
  • Poultry
  • Seafood
  • Beans
  • Dark leafy greens
  • Iron-fortified cereals and grains

Deficiency: causes, symptoms and risk groups

Iron deficiency is the most common nutritional deficiency worldwide. It can arise due to inadequate dietary intake, increased requirements, or chronic blood loss.

  • Risk groups: Infants and young children, women of childbearing age, pregnant women, individuals with certain chronic diseases, and people with poor dietary intake.
  • Signs and symptoms: Iron deficiency anemia, fatigue, impaired cognitive function, and weakened immune response.

Iron deficiency and its consequences may be addressed with appropriate dietary adjustments or supplementation under professional guidance.

Supplement forms

Ferrous fumarate is one of several iron salts available as supplements. Other common forms include:

Absorption and bioavailability

Iron from ferrous salts, including ferrous fumarate, is generally well absorbed. However, absorption can be influenced by a variety of dietary and physiological factors.

  • Enhancers: Vitamin C (ascorbic acid) and components of meat, fish, and poultry (sometimes called “meat factor”) can improve absorption.
  • Inhibitors: Phytates (found in grains and legumes), polyphenols (in tea and coffee), calcium, and certain medications may reduce iron absorption.

Ferrous fumarate has comparable bioavailability to other ferrous salts, but individual tolerance and absorption may vary.

Potential benefits: what does the evidence say?

Correction of iron deficiency anemia: There is strong human evidence that ferrous fumarate supplementation effectively increases iron stores and helps correct iron deficiency anemia in diverse populations.

Effectiveness depends on baseline iron status, supplemental dose, adherence to treatment, and presence of absorption enhancers or inhibitors.

Side effects and toxicity

  • Common side effects include gastrointestinal discomfort, nausea, constipation, and dark stools.
  • Excessive iron intake can lead to toxicity, causing gastrointestinal symptoms and, in severe cases, organ damage.
  • Adhering to established tolerable upper intake levels is important to avoid adverse effects.
  • Special caution is recommended for children due to the risk of accidental overdose and for individuals with iron overload disorders such as hemochromatosis.

Drug and nutrient interactions

While no specific interactions unique to ferrous fumarate were supplied, iron supplements can interact with certain medications and nutrients, potentially affecting their absorption or efficacy. It is advisable to discuss with a healthcare provider when combining iron supplements with other treatments.

Who should be careful?

  • Children, due to risk of accidental overdose
  • Individuals with hemochromatosis or other iron overload disorders
  • People who are pregnant, breastfeeding, or have medical conditions such as kidney disease or thyroid disease
  • Anyone taking medications that may interact with iron

Consultation with a healthcare professional is recommended before starting supplementation, especially in these groups.

Frequently asked questions

  • Is ferrous fumarate better than other iron salts?
    Evidence shows ferrous fumarate has bioavailability comparable to other ferrous salts. Individual tolerance may vary, but no clear superiority has been established.
  • Can I take ferrous fumarate on an empty stomach?
    Iron supplements are generally better absorbed on an empty stomach, but gastrointestinal side effects may be reduced when taken with food.
  • How long does it take to correct iron deficiency anemia with ferrous fumarate?
    Improvement depends on the severity of deficiency, dose, and adherence, but typically several weeks to months of supplementation are needed.
  • Are there risks in taking too much ferrous fumarate?
    Yes, excess iron intake can cause toxicity. It is important to adhere to recommended doses and safety guidelines.

Evidence limitations

  • No specific EU-authorized health claims were identified for ferrous fumarate in the supplied evidence.
  • Comparative data on different ferrous salt forms are limited in the provided information.
  • Safety details are incomplete, especially regarding toxicity thresholds specifically for ferrous fumarate.

References

Disclaimer: This page is intended for informational purposes only and does not substitute for professional medical advice. Individuals who are pregnant, breastfeeding, have existing medical conditions, kidney or thyroid disease, iron overload disorders, or are taking medications should consult a healthcare professional before using iron supplements such as ferrous fumarate.

Last reviewed: June 2024