Iron from complex salts and its bioavailability to rats

Area of Science:

• Nutritional Science
• Biochemistry
• Toxicology

Background:

• Complex iron compounds are increasingly utilized as iron fortifiers.
• Assessing the bioavailability of iron from these compounds is crucial for human and animal nutrition.
• Ferrous sulfate is a common reference standard for iron bioavailability studies.

Purpose of the Study:

• To compare the iron bioavailability of three complex iron compounds (ferric orthophosphate, sodium iron EDTA, iron glycine chelate) against ferrous sulfate.
• To evaluate the efficacy of these iron complexes as prophylactic iron suppliers in a rat model.
• To establish a practical and feasible method for testing iron salt bioavailability.

Main Methods:

• A prophylactic iron study was conducted using weanling rats fed low-iron diets supplemented with different iron compounds.
• Diets were fortified to 20 mg Fe/kg with ferrous sulfate, ferric orthophosphate, sodium iron EDTA, or iron glycine chelate.
• Rats were monitored for 5 weeks, with measurements of weight gain, food intake, and analysis of blood and liver iron content.

Main Results:

• Sodium iron EDTA and iron glycine chelate demonstrated iron bioavailability and biological value comparable to ferrous sulfate.
• Ferric orthophosphate exhibited a significantly lower biological value for iron compared to ferrous sulfate and the other tested iron complexes.
• The iron rat assay proved effective for comparing the bioavailability of different iron salts.

Conclusions:

• Sodium iron EDTA and iron glycine chelate are effective iron suppliers with high bioavailability in rats.
• Ferric orthophosphate has a lower iron bioavailability compared to ferrous sulfate and other tested iron complexes.
• The rat model is a suitable method for evaluating iron bioavailability from various iron compounds.