Minerals and Trace Elements in Human Breast
Milk Are Associated with Guatemalan Infant Anthropometric Outcomes
within the First 6 Mo.
J Am Coll Nutr. 2016 Jul 27:1-8. [Epub ahead of print]
Li C, et al.
(AA) 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.
OBJECTIVES: 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
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
Breast milk may be inadequate in selected minerals and trace elements
where higher estimated intakes were associated with greater infant