The invention relates to a process for separating milk components, wherein proteins, sugars and minerals are separated into different fractions. The lactose of milk is first hydrolyzed completely or partially, after which proteins, minerals and sugars are separated into fractions in a phased nanofiltration. The obtained fractions may also be further processed by chromatography, membrane techniques, and/or evaporation to further improve the separation of said components. The invention also relates to a low-lactose or lactose-free milk composed of these fractions. By means of the invention, calcium and protein losses can be minimized. Also, the energy content of the product can be reduced.