Mature breast milk looks very different from colostrum, the milk produced in the first few days after birth. According to Guthrie (1989), each 100 mL of colostrum yields approximately: • 58 calories. • 5.3 g carbohydrates. • 2.9 g fat. • 3.7 g protein. Colostrum is low in fat and carbohydrates. As a result, there are fewer calories in breast milk for the first few days of a baby’s life. Colostrum is yellow because it contains high levels of beta carotene (10 times more than is found in mature milk). Colostrum also contains elevated levels of vitamin E and zinc.