Free and acyl-carnitines in human milk and colostrum: 89

Abstract

We observed that newborns fed soy based formulas essentially free of carnitine demonstrated lower levels of free and acyl-carnitines in plasma than newborns that were breastfed or were fed with other types of milk. We, therefore, inferred an essential role of carnitine in nutrition during the first weeks of life and studied the concentration of free carnitine, acyl-carnitines, triglycerides and proteins in colostrum and human milk. We analyzed 93 samples of human milk obtained from 14 mothers. Of these, 9 were obtained during the first 5 days of lactation while 5 were specimen obtained during the second month of nursing. The milk was collected at the onset and at the end of each Seeding from each breast once in the morning and evening. Colostrum when compared with mature milk showed increased concentration of free carnitine (45±12.56 versus 32.41±9.63 SD nmol/ml) and proteins (15.95±3.96 versus 7.88±1.83 SD mg/ml) but reduced content of triglycerides (6.00±3.38 SD versus 11.89±6.64 SD nmol/ml). All these changes were significant (p<.O01). Single samples in each mother showed significant correlation both in colostrum and mature milk in the levels of free carnitine and proteins. Colostrum is, therefore, an important nutrient in the metabolic transition between fetal and postnatal life: it contains essential aminoacids in the form of proteins, and is low in triglycerides. The elevated level of carnitine seems to promote the newborn adaptation in utilizing long chain fatty acid. During fetal life glucose and amino acids are prevalently used as a metabolic fuel and fatty acid oxidation is low.