Submitted to: Advances in Food and Nutrition Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/5/1997
Publication Date: N/A
Interpretive Summary: Lactation is a very important source of nutrients to infants, and the accurate measurement of lactation through modeling has important nutritional applications. For example, if a nutrient is supplemented to a mother, and the appearance of the nutrient in the breast milk is measured, then an accurate prediction of infant breast milk intake would reveal the exposure of the infant to that nutrient. The traditional means for determining breast milk intake is test-weighing, a method which is cumbersome and inconvenient. An alternative method is isotope dilution. Isotope dilution for determination of breast milk intake was first introduced by Coward and colleagues in 1979. In this manuscript we describe, in detail, the means for determining infant breast-milk intake by isotope dilution combined with compartmental modeling. The methods described in this manuscript will be particularly useful to two groups of scientists: (1) those needing to master and use compartmental modeling with isotope dilution techniques for field measurements of human lactation and (2) those needing to learn basic techniques of mathematical modeling.
Technical Abstract: Isotope dilution for measurement of human lactation in field studies is a favorable alternative to the test-weighing technique. In this manuscript, the use of compartmental modeling to analyze isotope dilution data is described in detail. Isotope enrichment data presented here were collected from mother-infant pairs after the mothers each received a single 30-gram dose of deuterium oxide. Samples of breast milk were collected on days 1, 2, 12, and 14 following the dose, and samples of infant urine were collected on days 1, 2, 3, 4, 6, 8, 10, 12, and 14 following the dose. Deuterium enrichment of the samples was determined by isotope ratio mass spectrometry. Enrichment data were analyzed using compartmental modeling. The modeling techniques described here allow the accurate determination of human lactation from the deuterium oxide enrichment of mother's milk and infant's urine.