Effects of Dietary Vitamin D Levels on the in Vitro Mineralization of Chick Metaphyses 1 2

Summary

Chicks fed a rachitogenic diet became hypocalcemic and formed hypomineralized bones compared with chicks fed a control diet. Undemineralized metaphyseal slices from rachitic chicks incubated for five days in media with four different Ca-P concentration products had significantly less mineral deposited than slices from control chicks or chicks fed the rachitogenic diet supplemented with Ca. The latter chicks formed normally mineralized bones and had serum Ca values intermediate between those of the rachitic and control chicks. The data support the concept that hypomineralization of rachitic bone in vivo is mainly due to reduced serum Ca levels, but in addition show that hypomineralized rachitic bone, when tested in vitro, has lost some of its ability to serve as a calcification matrix.