Hepcidin Status at 2 Months in Infants Fed Breast Milk Compared with Formula

Abstract

<b><i>Introduction:</i></b> The basis for the superior absorption of iron from breast milk compared with infant formulas is unclear. The hormone hepcidin downregulates dietary iron absorption. Hepcidin production increases with increased body iron status (reflected in serum ferritin levels). We hypothesized that serum hepcidin levels are suppressed relative to iron status in infants fed breast milk compared with formula. <b><i>Methods:</i></b> Subjects were healthy infants presenting for routine 2-month clinic visit and strictly fed either breast milk or standard infant formula. Urinary hepcidin and ferritin levels (reflective of serum levels) were analyzed and compared across the breast milk- and formula-fed groups. The relationship between urinary hepcidin and ferritin levels within each group was analyzed by linear regression. <b><i>Results:</i></b> Twenty-four subjects were enrolled in each group. The median urinary hepcidin level in the group fed breast milk was lower than in formula (130 vs. 359 ng hepcidin/mg creatinine, <i>p</i> < 0.05). However, the median ferritin levels were similar (2.1 vs. 1.9 ng/mL). Within each group, urinary hepcidin correlated with urinary ferritin (<i>r</i> = 0.5, <i>p</i> < 0.05 for each group); however, the slope of the regression line was lower in the group fed breast milk compared with formula (<i>p</i> < 0.005). <b><i>Conclusion:</i></b> Despite similar urinary ferritin levels, urinary hepcidin levels are lower at 2 months in infants fed breast milk compared with infants fed formula. Hepcidin levels correlate with iron status in each group; however, this relationship is relatively dampened in infants fed breast milk. We speculate that relatively lower infant hepcidin contributes to the superior efficiency of iron absorption from breast milk.

Non Breast-Milk-Fed Very Preterm Infants Are at Increased Risk of Iron Deficiency at 4–6-Months Corrected Age: A Retrospective Population-Based Cohort Study

“…Additionally, the hormone lactoferrin, present in high concentrations in breast-milk, may contribute to increased iron absorption in infants [23,24]. A recent study showed that breast-milk-fed infants have lower levels of serum hepcidin than formula-fed infants, despite similar urinary ferritin levels [25]. Hepcidin is a hormone that has been shown to sequester iron in hepatocytes, diminishing the serum iron available for use in erythropoiesis [26,27].…”

Iron deficiency in infancy: current insights

“…Contrary to this, Dewan et al [14] concluded that serum hepcidin is not useful to detect IDA in infants but instead suggested that the predictive value for IDA was higher from urinary Hepcidin. Reference ranges for Hepcidin at different ages have been suggested but there is a lack of standardized laboratory methods and the ranges diverge [8 & , [15][16][17][18]. Another more recently suggested biomarker is reticulocyte Hb (Chr).…”

Early Human Iron Equilibrium: A Review

“…There are differences in the absorption and utilization of iron in the nursing infant compared to the formula fed infant with varying intestinal iron binding mechanisms and iron binding proteins. Additionally, the premature infant may have different iron absorptive mechanisms and risk factors compared to the term infant [44,[69][70][71][72][73][74][75].…”

“…It is suggested that iron redistribution may occur in the gastrointestinal tract such that most iron is incorporated into lactoferrin [44], unique iron absorption by a specific receptor in the small intestine of newborn infants is proposed [66,70]. A recent study found that urinary hepcidin levels in infants fed breastmilk compared to formula were lower, suggesting that the lower infant hepcidin levels contribute to milk iron bioavailability [71].…”