There are many reasons a mother may not produce enough breast milk. Some of the most common are an improper latch (i.e. the baby does not connect efficiently with the nipple), not nursing or pumping enough to meet supply, certain medications (including the contraceptive pill), illness, and dehydration. A rarer reason is Sheehan's syndrome, also known as postpartum hypopituitarism, which is associated with prolactin deficiency; this rare syndrome may require hormone replacement.
Lack of supply can be addressed by nursing and/or pumping more frequently. The more the mother nurses her baby, or pumps, the more milk is produced. It is very helpful to nurse on demand - to nurse when the baby wants to nurse rather than on a schedule. If pumping; it is helpful to have an electric high grade pump so that all of the milk ducts are stimulated. Some mothers try to increase their milk supply in other ways - by taking the herb fenugreek, used for hundreds of years to increase supply ("Mother's Milk" teas contain fenugreek as well as other supply-increasing herbs); there are also prescription medications that can be used, such as Domperidone (off-label use) and Reglan. Increasers of milk supply are known as galactagogues.
Human milk contains 0.8% to 0.9% protein, 3% to 5% fat, 6.9% to 7.2% carbohydrates and 0.2% ash (minerals). Carbohydrates are mainly lactose; several lactose-based oligosaccharides have been identified as minor components. The principal proteins are casein homologous to bovine beta-casein, alpha-lactalbumin, lactoferrin, IgA, lysozyme and serum albumin. Non-protein nitrogen-containing compounds, making up 25% of the milk's nitrogen, include urea, uric acid, creatine, creatinine, amino acids and nucleotides.
Though now it is almost universally prescribed, in the 1950s the practice of breastfeeding went through a period where it was out of vogue and the use of infant formula was considered superior to breast milk.
However, it is now universally recognized that there is no commercial formula that can equal breast milk. In addition to the appropriate amounts of carbohydrate, protein and fat, breast milk also provides vitamins, minerals, digestive enzymes and hormones - all of the things that a growing infant will require. Breast milk also contains antibodies and lymphocytes from the mother that help the baby resist infections. The immune function of breastmilk is individualized, as the mother, through her touching and taking care of the baby, comes into contact with pathogens that colonize the baby and consequently her body makes the appropriate antibodies and immune cells. This is a process that obviously cannot be replicated on an industrial basis.
Women who are breastfeeding should consult with their physician regarding substances that can be unwittingly passed to the infant via breast milk, such as alcohol, viruses (HIV or HTLV-1) or medications.
Most women who do not breastfeed use infant formula, but breast milk donated by volunteers to human milk banks can be obtained by prescription. Cow's milk is recommended as a substitute, but only for children over one year of age.
Whole cow's milk does not contain sufficient vitamin E, iron, or essential fatty acids, which can make infants fed on cow's milk anemic. Whole cow's milk also contains excessive amounts of protein, sodium, and potassium which may put a strain on an infant's immature kidneys. In addition, the proteins and fats in whole cow's milk are more difficult for an infant to digest and absorb than the ones in breast milk. Evaporated milk may be easier to digest due to the processing of the protein but is still nutritionally inadequate. A significant minority of infants are allergic to one or more of the constituents of cow's milk, most often the high amounts of lactose (milk sugars) and agglutinin. These problems can also affect infant formulas derived from cow's milk.
Preliminary research indicates that breast milk can induce apoptosis in some types of cancer cells . Adults with GI disorders and organ donation recipients can also benefit from the immunologic powers of human breast milk. More research is needed in these areas.
In Costa Rica, there have been trials to produce cheese and custard from human milk as an alternative to weaning.
A controversial Swiss restaurateur has created a menu based around foods cooked in human breast milk .