Method for the preparation of dairy products with a lactose content less than 0.1 % by weight, which is characterized in that the starting milk or its hydrolysis product before further treatment is subjected to a step in which the predominant amount of calcium is precipitated, comprising the following steps: heating a starting milk to 55 to 65 °C over a period of 5 to 25 minutes; ultrafiltration of the precipitation product of step to produce a first permeate P1 and a first retentate R1; reverse osmosis of the first permeate P1 to produce a second permeate P2 and a second retentate R2; decalcifying the second retentate R2; ultrafiltration of the decalcified product of step to produce a third permeate P3 (lactose concentrate) and a third retentate R3 (mineral concentrate); mixing the first retentate R1 with in each case such an amount of the third permeate P3 and the third retentate R3 to obtain a standardized milk product with a defined concentration of lactose and salts and hydrolysing the standardized milk product from step adding such an amount of lactase that the amount of lactose contained in the product is completely cleaved into glucose and galactose; or Hydrolysis of a starting milk with the addition of lactase; heating the hydrolysis product of step to about 55 to about 65 °C over a period of about 5 to about 25 minutes; nanofiltration of the precipitation product of step to produce a first permeate P1 and a first retentate R1; reverse osmosis or nanofiltration of the first permeate P1 to produce a second permeate P2 and a second retentate R2; mixing the first retentate R1 with in each case such an amount of the second permeate P2 and second retentate R2 to obtain a standardized milk product whose content of proteins and minerals corresponds to that of the starting milk, and optionally hydrolysis of the standardized milk product from step with addition of such an amount of lactase that the remaining amount of lactose still contained in the product is completely cleaved into glucose and galactose; oder heating a starting milk to 55 to 65 °C over a period of 5 to 25 minutes; ultrafiltration of the precipitation product of step to produce a first permeate P1 and a first retentate R1; nanofiltration of the first permeate P1 to produce a second permeate P2 and a second retentate R2; hydrolysis of the second retentate R2 with the addition of lactase; mixing the first retentate R1 with in each case such an amount of the second permeate P2 and of the hydrolysis product from step, so that a standardized milk product is obtained whose content of proteins and minerals corresponds to that of the starting milk and optionally hydrolysis of the standardized milk product from step with addition of such an amount of lactase that the remaining amount of lactose still contained in the product is completely cleaved into glucose and galactose. heating a starting milk to 55 to 65 °C over a period of 5 to 25 minutes; ultrafiltration of the precipitation product of step to produce a first permeate P1 and a first retentate R1; reverse osmosis of the first permeate P1 to produce a second permeate P2 and a second retentate R2; decalcifying the second retentate R2; ultrafiltration of the decalcified product of step to produce a third permeate P3 (lactose concentrate) and a third retentate R3 (mineral concentrate); mixing the first retentate R1 with in each case such an amount of the third permeate P3 and the third retentate R3 to obtain a standardized milk product with a defined concentration of lactose and salts and hydrolysing the standardized milk product from step adding such an amount of lactase that the amount of lactose contained in the product is completely cleaved into glucose and galactose; or Hydrolysis of a starting milk with the addition of lactase; heating the hydrolysis product of step to about 55 to about 65 °C over a period of about 5 to about 25 minutes; nanofiltration of the precipitation product of step to produce a first permeate P1 and a first retentate R1; reverse osmosis or nanofiltration of the first permeate P1 to produce a second permeate P2 and a second retentate R2; mixing the first retentate R1 with in each case such an amount of the second permeate P2 and second retentate R2 to obtain a standardized milk product whose content of proteins and minerals corresponds to that of the starting milk, and optionally hydrolysis of the standardized milk product from step with addition of such an amount of lactase that the remaining amount of lactose still contained in the product is completely cleaved into glucose and galactose; oder heating a starting milk to 55 to 65 °C over a period of 5 to 25 minutes; ultrafiltration of the precipitation product of step to produce a first permeate P1 and a first retentate R1; nanofiltration of the first permeate P1 to produce a second permeate P2 and a second retentate R2; hydrolysis of the second retentate R2 with the addition of lactase; mixing the first retentate R1 with in each case such an amount of the second permeate P2 and of the hydrolysis product from step, so that a standardized milk product is obtained whose content of proteins and minerals corresponds to that of the starting milk and optionally hydrolysis of the standardized milk product from step with addition of such an amount of lactase that the remaining amount of lactose still contained in the product is completely cleaved into glucose and galactose.