The effect of casein phosphopeptides on calcium utilization in young ovariectomized rats.

The effect of casein phosphopeptides (CPPs) on Ca utilization in ovariectomized (OVX) rats was studied. A mixture of CPPs corresponding to the amino acid sequences 1-25 and 1-28 in the beta-casein was isolated from the tryptic digest of beta-casein (beta CPP). After being fed a low Ca diet for 30 days, OVX rats were fed experimental diets of which the Ca level was 0.1%, 0.3% or 0.5% with or without 0.15% beta CPP for 28 days. During days 1-3 of the Ca refeeding period, rats fed beta CPP with 0.5% Ca showed a higher Ca absorption than control rats not supplemented with beta CPP. During days 7-9 and 26-28, there were no significant differences in Ca and P balances between the beta CPP group and the control group for each dietary Ca level. Femoral Ca and P contents from rats fed beta CPP tended to be higher than those from control rats. These results suggest that beta CPP supplementation could have an effect on Ca absorption at a certain degree of Ca deficiency.