Cow’s milk differs from human milk in having a higher concentration of protein and salts. The kinds of protein and the salts are somewhat different too. The calorie content (that is, the number of calories per
ounce) is about the same. Both milks contain adequate amounts of vitamin A but are deficient in vitamin D and may be lacking in vitamin C. Neither human milk nor cow’s milk has enough iron. A continuing deficiency of iron through infancy can bring on anemia. If we gave the newborn undiluted cow’s milk, the higher concentrations of salts and protein would put a heavier load on his kidneys than he would get from human milk.
In ordinary circumstances a healthy baby could carry this load, but some unusual stress might change the picture. By lowering the level of the bodily fluids. diarrhea, vomiting, or profuse sweating (all frequent accompaniments of illness) could increase the concentration of salts and protein. An undesirable accumulation of salt and protein waste products in the bloodstream would result. It is to prepare for such contingencies in non-breast-fed infants that we modify cow’s milk before we give it to infants. Mainly, we want to reduce the concentrations of protein and salts in early infancy (three to four months) .
Such a modification is known as a formula. You can think of the formula your doctor will prescribe as a recipe for modifying cow’s milk to a better approximation of human breast milk. There are three basic types, the first two of which you can make in your own kitchen. The first uses canned evaporated milk, which is cow’s milk boiled to remove a certain amount of water. In the process, the protein is altered to produce a softer, better tolerated curd. The second uses fresh whole (usually homogenized) milk straight out of the dairy bottle. In both formulas water is added to reduce the concentrations of salts and protein.
This dilution also cuts the calorie concentration, and it becomes necessary then to restore the proportion by adding sugar of some kind. The final result with either the evaporated milk or the whole milk is a product much closer to human milk than to the cow’s milk with which we started. The third principal formula, also based on cow’s milk, differs from the others in being the product of a commercial factory.
The protein. fat, and salts of cow’s milk are altered to make it more like human breast milk. Vegetable fats arc substituted for the animal fats of the cow . Vitamins and usually iron are added. The final preparation is packaged for sale as a canned liquid concentrate or powder to which water must be added, or as an already diluted, bottled formula all ready for the baby. Like beer, the bottle formula is offered in convenient, tidy six-packs, one more illustration of how the merchandiser’s long arm reaches into our lives. There are three major brands of the commercial formulas.
your doctor will have his own recommendation to make, there does not appear to be any significant difference among them. Indeed, in respect to nutrition, science has not been able to demonstrate any significant difference between these formulas and human breast milk. The average baby will thrive on any of them.. This does not mean, however, that your own doctor will automatically prescribe a commercial formula for your baby. He may have his own reasons to prefer something else, or he may find that a particular baby does not tolerate standard formulas and needs something special.