title: Minerals and Trace Elements in Human Breast Milk Are Associated with Guatemalan Infant Anthropometric Outcomes within the First 6 Months.
abstract: BACKGROUND
  Breast milk is the recommended source of nutrients for infant growth, but its adequacy to meet infants' mineral and trace element needs is unknown.
  
  
  OBJECTIVE
  We used breast-milk mineral and trace element concentrations of Guatemalan mothers at 3 lactation stages to estimate total daily intakes and to determine whether intakes were associated with early infant growth.
  
  
  METHODS
  In this cross-sectional study, breast-milk samples were collected from Mam-Mayan mothers during transitional (5-17 d, n = 56), early (18-46 d, n = 75), and established (4-6 mo, n = 103) lactation; z scores for weight (WAZ), length (LAZ), and head circumference (HCAZ) were measured. Concentrations of 11 minerals (calcium, potassium, magnesium, sodium, copper, iron, manganese, rubidium, selenium, strontium, and zinc) were analyzed by inductively coupled plasma-mass spectrometry (ICP-MS). WHO equations were used to calculate the estimated energy requirement, which was divided by the energy density of breast milk to estimate daily milk volume, and this number was multiplied by breast-milk mineral concentrations to estimate intakes. Principal component analyses identified clusters of minerals; principal components (PCs) were used in regression analyses for anthropometric outcomes.
  
  
  RESULTS
  Estimated breast-milk intakes during established lactation were insufficient to compensate for the lower milk sodium, copper, manganese, and zinc concentrations in male infants and the lower sodium, iron and manganese concentrations in female infants. Estimated intakes of calcium, magnesium, potassium, sodium, and selenium were below the Institute of Medicine Adequate Intake for both sexes at all 3 stages of lactation. In early lactation, multiple linear regressions showed that PC1 (calcium, magnesium, potassium, rubidium, and strontium intakes) was positively associated with WAZ, LAZ, and HCAZ. In established lactation, the same PC with sodium added was positively associated with all 3 anthropometric outcomes; a second PC (PC2: zinc, copper, and selenium intakes) was associated with WAZ and LAZ but not HCAZ.
  
  
  CONCLUSIONS
  Breast milk may be inadequate in selected minerals and trace elements where higher estimated intakes were associated with greater infant growth.
authors: School of Dietetics and Human Nutrition.
authors: Chen
authors: http://orcid.org/0000-0003-3523-1629
authors: C
authors: Li
authors: Center for Studies of Sensory Impairment, Aging, and Metabolism (CeSSIAM), Guatemala City, Guatemala.
authors: Noel W
authors: NW
authors: Solomons
authors: Institute of Parasitology, and Centre for Host-Parasite Interactions, McGill University, Montreal, Canada; and.
authors: Marilyn E
authors: ME
authors: Scott
authors: School of Dietetics and Human Nutrition, Centre for Host-Parasite Interactions, McGill University, Montreal, Canada; and kris.koski@mcgill.ca.
authors: Kristine G
authors: KG
authors: Koski
mesh_terms: D001835:Body Weight; D001942:Breast Feeding; D003430:Cross-Sectional Studies; D005260:Female; D006166:Guatemala; D006801:Humans; D007223:Infant; D007227:Infant Nutritional Physiological Phenomena; D007774:Lactation; D016014:Linear Models; D008297:Male; D008895:Milk, Human / Q000737:chemistry*; D015596:Nutrition Assessment; D009751:Nutritional Requirements; D025341:Principal Component Analysis; D014131:Trace Elements / Q000008:administration & dosage / Q000032:analysis* / Q000172:deficiency; D014944:World Health Organization
chemical_list: D014131:Trace Elements
keywords: adequate intakes; human breast milk; infant anthropometry; minerals and trace element concentrations; stage of lactation