[Nutrient content in human milk: protein, lactose, minerals, trace elements, and thiamin (author's transl)]

Human milk from different periods of lactation was analysed. The following constituents of 100 g human milk decrease from the 1st week to the 2nd-3rd month of lactation: protein from 1.57 to 0.81 g, ash from 0.36 to 0.21 g, sodium from 54.4 to 13.1 mg, potassium from 63.6 to 48.1 mg, chloride from 109.8 to 39.1 mg and sulfur from 28.0 to 11.9 mg. There are no significant changes during lactation for calcium with 28.8-25.6 mg and for magnesium with 3.3 mg. The concentration of phosphorus increases during the first week of lactation from 8 to 12 mg/100 g and remains at this level. Zinc decreases from 642 to 166 micrograms milk during lactation. The concentration of manganese is between 1.1 to 1.8 micrograms. The almost similar concentration of iron and copper increases during the first 14 days of lactation from 48.4 to 62.2 micrograms and 45.8 to 66.9 micrograms respectively, and then decreases to 26.0 and 30.7 micrograms respectively in the 2nd-3rd month of lactation. During the period of lactation there is an increase for lactose from 4.9 to 6.1 g and for total-thiamin from 10.1 to 284 micrograms/100 ml.