Mature breast milk, which typically comes in a few days after a woman has given birth, is composed of 3 to 5 percent fat and an impressive list of minerals and vitamins: sodium, potassium, calcium, magnesium, phosphorous, and vitamins A, C, and E. Long-chain fatty acids like DHA (docosahexaenoic acid, an omega-3 fatty acid) and AA (arachidonic acid, an omega-6 fatty acid)—both critical to brain and nervous-system development—also abound in mother’s milk.
