Vitamin E in Human Milk and Its Relation to the Nutritional Requirement of the Term Newborn

OBJECTIVES To determine the alpha-tocopherol concentration in breast milk at different periods of lactation and to estimate the possible supply of vitamin E to the infant. METHODS A longitudinal observational study was carried out with 100 mothers at University Hospital Ana Bezerra (HUAB), at Universidade Federal do Rio Grande do Norte, in Santa Cruz (RN), Northeast Brazil. Samples of colostrum (n=100), transitional milk (n=77), and mature milk (n=63) were collected. Alpha-tocopherol was analyzed by high-performance liquid chromatography. Vitamin supply to the newborn was estimated by comparing the nutritional requirement of vitamin E (4 mg/day) with the potential daily intake of milk. RESULTS The mean alpha-tocopherol concentration found in colostrum, transitional, and mature milk was 40.5±15.0 µmol/L, 13.9±5.2 µmol/L, and 8.0±3.8 µmol/L, respectively (p<0.001). The possible effect of these milks offered to the infant 6.2 mg/day of vitamin E in colostrum, 4.7 mg/day in transitional milk, and 2.7 mg/day in mature milk (p<0.0001), shows that only the mature milk did not guarantee the recommended quantity of this vitamin. CONCLUSIONS Alpha-tocopherol levels in human milk decrease through the progression of lactation, and the possible intake of colostrum and transitional milk met the nutritional requirement of the infant. Mature milk may provide smaller amounts of vitamin E. Thus, it is important to study the factors that are associated with such low levels.