[Vitamin D sterol in human milk, cow's milk and baby food].

A review is given of the results of vitamin D determinations in human and cow's milk using physico-chemical methods. Thereby only parent vitamin D is determined. Further, the results obtained with protein-binding assays are discussed in detail. With the aid of these newer methods the concentrations of hydroxylated vitamin D derivatives can also be measured. A comparison of the concentration of these vitamin D metabolites in human milk and infant formulas based upon cow's milk suggests that the higher anti-rachitic activity of human milk is connected with its higher concentration of 25-hydroxy-vitamin D.