Mineral content of brands of milk for infant feeding

The amounts of sodium, potassium, phosphorus, and nitrogen in several brands of milk used for infant feeding have been measured, and the concentrations of these substances in the reconstituted milks calculated. The known variation in the electrolyte content of cows' milk and the addition of minerals in the manufacture of many types of milk foods may account for the variation in the content of these substances, but the addition of neutralized whey in the manufacture of Trufood Formula 4 increased the concentration of sodium to a level twice that found in undiluted cows' milk. We think that details of all mineral additions to milks used for infant feeding should be made readily available and that the mineral content of the powders or liquids should be printed on the containers and expressed both in mg/100 g and mEq/kg. Milks reconstituted to a composition close to that of cows' milk present large osmotic loads to the kidneys, and may endanger water balance in some circumstances. This risk can be reduced by a greater dilution with water.