A double stable isotope technique for measuring iron absorption in infants

Area of Science:

• Biochemistry
• Pediatric Nutrition
• Isotope Tracing

Background:

• Infant iron absorption is critical for development.
• Accurate measurement methods are needed to study dietary influences.
• Stable isotopes offer a non-radioactive approach.

Purpose of the Study:

• To develop and evaluate a stable isotope technique for simultaneous iron absorption measurement in infants.
• To assess iron absorption from a commercial infant formula using this new method.
• To enable paired comparisons of iron absorption influenced by dietary factors.

Main Methods:

• Utilized stable isotopes 57Fe and 58Fe as labels for simultaneous iron measurement.
• Administered labeled infant formula to healthy infants (13-25 weeks).
• Measured iron absorption via erythrocyte isotopic enrichment using mass spectrometry 14 days post-administration.

Main Results:

• Geometric mean iron absorption for 57Fe was 6.72% and for 58Fe was 6.58%.
• No significant difference was observed between the absorption of the two iron isotopes.
• The technique demonstrated reliability for paired iron absorption comparisons.

Conclusions:

• The stable isotope technique provides a reliable method for simultaneous infant iron absorption studies.
• This method facilitates systematic research into dietary factors affecting iron absorption in infants.
• The findings support the use of stable isotopes for precise nutritional assessments in pediatrics.