Ceruloplasmin concentration in human colostrum and mature milk.

The concentration of ceruloplasmin (CP) in human milk was obtained by measuring the increased absorbance of a solution containing apotransferrin and Fe2+ at 460 nm after adding the milk. The CP concentrations in colostrum and mature milk at less than 1 month after parturition were 4.45 +/- 1.23 mg and 4.09 mg +/- 1.47 mg/100 ml, respectively. In mature milk after more than one month, the CP concentration had decreased to 1.72 +/- 0.91 mg/100 ml.