Ferrous Fumarate: Use in Fortify Foods and Absorption in Young Children

General Description

Ferrous fumarate is a vital iron compound used for fortifying various food products, particularly infant and complementary foods. In the U.S., commercial infant cereals often use electrolytic iron, while European manufacturers typically prefer ferrous fumarate or ferric pyrophosphate. The World Health Organization supports the inclusion of ferrous fumarate in cereal-based foods, given its potential to enhance nutritional quality. However, studies indicate that the relative bioavailability (RBV) of ferrous fumarate in young children may be 30-35% lower than that of ferrous sulphate, raising concerns about its effectiveness in addressing iron deficiency. Despite some studies showing that ferrous fumarate can improve iron absorption, especially when combined with ascorbic acid, challenges remain regarding its efficacy compared to more readily bioavailable forms of iron. Ongoing research aims to evaluate ferrous fumarate's viability in food fortification and explore alternative iron compounds that ensure adequate nutritional support for vulnerable populations like infants and young children.

Figure 1. Ferrous Fumarate

Use in Fortify Foods

Ferrous Fumarate in the Context of Food Fortification

Ferrous fumarate is a significant iron compound used to fortify various food products, particularly in the context of infant and complementary foods. In the United States, commercial infant cereals often utilize electrolytic iron for fortification, while European manufacturers typically incorporate ferrous fumarate or ferric pyrophosphate. The Food for Peace Program in the U.S. specifically fortifies cereal and legume blends, such as corn soy blend, with ferrous fumarate. In addition, fortified flour products often utilize reduced (325 mesh) iron, though the specific type is not always identified. The World Health Organization guidelines advocate for several sources of iron compounds, including ferrous fumarate, to enhance the nutritional quality of cereal-based complementary foods. Importantly, due to the challenging absorption conditions posed by high levels of phytic acid in cereals and legumes, the addition of ascorbic acid is recommended to enhance iron absorption, which applies particularly to precooked commercial infant cereals. ¹

Relative Bioavailability

The recommendations regarding the use of ferrous fumarate in infant and young children's complementary foods are largely informed by studies on relative bioavailability (RBV) conducted in adults. These studies show that ferrous fumarate is well absorbed and comparable to ferrous sulphate, a more readily bioavailable iron compound. Although there is no direct evidence comparing iron absorption in adults versus infants, it is assumed that a high RBV for adults translates similarly to children. Some studies suggest that infants, particularly those aged between 6 to 9 months, demonstrate the ability to regulate their iron absorption based on dietary intake. Therefore, ferrous fumarate's high RBV for adults implies potential efficacy in infants and young children; however, these assumptions require further validation specific to this demographic. ¹

Concerns and Future Directions

Recent studies have raised concerns regarding the effectiveness of ferrous fumarate for fortifying complementary foods for young children. Findings indicate that the RBV of ferrous fumarate may be significantly lower—around 30-35%—when compared to ferrous sulphate in young children. This raises questions about the appropriateness of using ferrous fumarate in these applications, especially given the specific iron and ascorbic acid levels tested. The ongoing evaluation by SUSTAIN’s Food Aid Quality Enhancement Project aims to critically assess the viability of ferrous fumarate in infant food fortification. It also seeks to explore alternative iron compounds that may offer better absorption and nutritional support for infants and young children, ensuring that food fortification effectively addresses iron deficiencies in these vulnerable populations. ¹

Absorption in Young Children

Ferrous fumarate's absorption in infants and young children has been assessed through several studies, primarily utilizing intrinsically labeled ferrous fumarate with isotopes like 57Fe. Among the five studies published, only two directly compared the absorption of ferrous fumarate with ferrous sulphate in the same subjects. In one notable study involving Polish infants aged 6–12 months, a wheat/soy infant cereal fortified with 10 mg of ferrous fumarate showed an average iron absorption rate of 4.1%, significantly higher than the 1.3% absorption from a similar cereal fortified with ferric pyrophosphate. Another study included children aged 6–18 months who received ferrous fumarate encapsulated in oil as part of a micronutrient mix, yielding varying absorption rates of 4.5% to 8.2%, depending on the children's iron status. These results highlight the potential of ferrous fumarate to enhance iron absorption in young children, particularly when paired with ascorbic acid, which is known to improve iron bioavailability. ²

Comparative Effectiveness

Recent comparative studies have raised concerns about the relative bioavailability of ferrous fumarate when contrasted with ferrous sulphate in young children. In investigations conducted in Bangladesh and Mexico, children consuming complementary foods fortified with ferrous fumarate demonstrated significantly lower iron absorption, averaging around 5.4% to 6.4%, compared to 16.6% to 22.5% from ferrous sulphate in similar contexts. However, a pivotal study in South Africa indicated that maize meal fortified with 27.5 mg of ferrous fumarate effectively improved iron status, with significant increases in hemoglobin and decreased anemia prevalence noted. Furthermore, a double-blind efficacy study in Bangladesh suggested that ferrous fumarate could maintain adequate iron status in iron-replete children as effectively as ferrous sulphate, when fortified with ascorbic acid. These findings suggest that while ferrous fumarate's absorption may be lower than that of ferrous sulphate, it is still beneficial for improving iron levels in infants and young children, warranting further exploration of its fortification potential in complementary foods. ²

Reference

1. Hurrell R. Use of ferrous fumarate to fortify foods for infants and young children. Nutr Rev. 2010; 68(9): 522-530.

2. Perez-Exposito AB, Villalpando S, Rivera JA, Griffin IJ, Abrams SA. Ferrous sulfate is more bioavailable among preschoolers than other forms of iron in a milk-based weaning food distributed by PROGRESA, a national program in Mexico. J Nutr. 2005; 135: 64–69.