Comparison of mineral content in breast milk between early and later lactation periods among indigenous women from Western Highlands of Guatemala (623.11)

Background : Human breast milk is the normal source of minerals for infant growth, development and metabolic function up to 6 months, but little information is available about how mineral concentrations vary throughout lactation in developing countries. Our objectives were to compare mineral concentrations between early (<45d) and later (4‐6mo) lactation periods, and to determine if mineral concentrations varied with infant age within these two lactation periods. Methods : Inductively Coupled Plasma Mass Spectrometry was used to analyze the concentration of 13 minerals (Na, K, Ca, Mg, Mn, Zn, Cu, Cr, Sr, Se, Rb, Fe, P) in early (n=54) and later (n=49) breast milk samples collected from Mam ‐Mayan women from rural villages in the Western Highlands of Guatemala. Results : Median concentrations of Na, K, Mn, Zn, Cu, Cr, Rb and Fe were significantly higher in early milk compared with later milk whereas Mg was lower in early milk. No differences were observed between lactation period for Ca, Se and Sr. Within the first 45d, Na, K, Cu and Zn were negatively correlated with infant age. During the 4‐6mo interval, only Se was negatively correlated with infant age. Conclusion : Our findings reveal that concentrations of Na, K, Cu and Zn decreased within the first 45d, that Mn, Cr, Rb and Fe had declined by 4‐6mo, and that Se declined during the 4‐6mo interval. Grant Funding Source : McGill University International Mobility Award, NSERC