Submitted to: Journal of Federation of American Societies for Experimental Biology
Publication Type: Abstract Only
Publication Acceptance Date: 12/1/2003
Publication Date: 3/23/2004
Citation: Hunt, C.D., Friel, J. 2004. Boron concentrations in milk from mothers of full-term, but not premature, breast-fed infants remain stable during the first three months of lactation while copper, iron, selenium, and zinc concentrations decrease regardless of gestational length [abstract]. The Federation of American Societies for Experimental Biology Journal. 18:A492.
Technical Abstract: To establish dietary intakes of boron of breastfed infants, we analyzed human milk from lactating mothers of premature (PRT, n = 10, < 2000 g birth weight, < 37 wk gestation) and full-term (FT, n = 10, > 2500 g, 39-41 wk gestation) infants living in St John's, Newfoundland, Canada. Samples were collected once a week for 12 wk and analyzed for boron, copper, iron, selenium, and zinc by inductively coupled plasma-mass spectrometry after wet ash digestion with HNO3 and H2O2 in Teflon tubes. A mixed model ANOVA indicated that boron concentrations were stable in FT but not PRT milk between wk 1 and wk 12 (FT: 0.030 to 0.028 ug/g milk, p = 0.5; PRT: 0.034 to 0.025; p = 0.01). As expected, there was a reduction in the concentrations of copper (FT: 0.651 to 0.360 ug/g, p < 0.0001; PRT: 0.542 to 0.425, p = 0.05), iron (FT: 0.355 to 0.225 ug/g, p = 0.0003; PRT: 0.406 to 0.287, p = 0.002), selenium (FT: 0.027 to 0.019 ug/g, p <0.0001; PRT: 0.028 to 0.020, p <0.0001), and zinc (FT: 4.06 to 1.19 ug/g, p <0.0001; PRT: 5.97 to 1.27, p <0.0001) over time. Copper decreased more rapidly in FT than PRT milk (p = 0.02). The stability of boron concentrations in milk over time is similar to that reported earlier for magnesium and calcium and suggests that boron is either homeostatically regulated or that the release of boron during lactation-induced bone catabolism is sufficient to maintain milk boron concentrations.