Related Experiment Videos
Iron, zinc, copper and selenium status of breast-fed infants and infants fed trace element fortified milk-based
1Department of Nutrition, University of California, Davis.
Insights
Infant formula with 4 mg iron/L is adequate for 1.5 to 6-month-olds. Higher iron levels (7 mg/L) in formula may negatively impact selenium and copper status in infants.
Area of Science:
- Pediatrics
- Nutrition Science
- Infant Health
Background:
- Iron fortification in infant formula is crucial for preventing deficiency.
- Optimal iron levels in formula are debated, with potential impacts on other micronutrients.
- Breast milk serves as a benchmark for infant nutrition.
Purpose of the Study:
- To compare hematological status in infants fed formulas with different iron concentrations (4 mg/L vs. 7 mg/L) and breast milk.
- To evaluate the effect of iron levels on selenium and copper status in infants.
- To assess serum transferrin receptor levels as an indicator of iron status.
Main Methods:
- Comparative study involving three groups of infants (1.5-6 months old).
- Infants received cow's milk-based formulas (4 mg iron/L or 7 mg iron/L) or were breast-fed.
- Hematological indices, serum transferrin receptor, selenium, and copper levels were measured.
Main Results:
- No significant differences in hematological indices or iron status were observed at 6 months.
- Breast-fed infants had higher serum transferrin receptor levels, indicating a cellular need for iron.
- Infants fed 7 mg iron/L formula showed lower selenium and copper status compared to other groups.
Conclusions:
- 4 mg iron/L in infant formula appears adequate for infants up to 6 months.
- Higher iron fortification (7 mg/L) may have adverse effects on selenium and copper status.
- Further research into optimal iron levels and their interaction with other micronutrients is warranted.
Abstract:
Infants were fed cow's milk-based formulas containing 4 mg of iron/l from 1.5 to 6 months of age and their hematological status was compared to infants receiving the same formula but with 7 mg of iron/l and with breast-fed infants. One formula with 4 mg of iron/l contained iron as ferrous sulfate, in another, part of the iron was provided as bovine lactoferrin. We also studied the effect of selenium (10 micrograms/l) and copper (0.4 mg/l) supplementation on selenium and copper status. There were no significant differences in hematological indices among the groups at 6 months of age; all infants had satisfactory iron status. Serum transferrin receptor levels, a potential novel indicator of iron status, were highest in breast-fed infants, suggesting a cellular need for iron, and lowest in infants receiving formula with 7 mg of iron/l. Selenium status, as assessed by serum glutathione peroxidase activity, was similar at 6 months of age in breast-fed infants and infants fed formula fortified with selenium but lower in infants fed unfortified formula. The lowest levels of glutathione peroxidase activity were found in infants fed the highest concentration of iron (7 mg/l). Serum copper concentrations were similar in all groups, but the lowest levels were found in infants fed the highest concentration of iron. These results suggest that 4 mg of iron/l is adequate for infants up to 6 months of age and that higher levels may have some negative effects.