Principal component analysis (PCA) score plots of rats in the low-calcium group (LCG) and normal-calcium group (NCG). (A-C) Week 2, n = 48 (for two components, R2Y = 45.0%, Q2 = 24.1%); week 4, n = 32 (for three components R2Y = 54.6%, Q2 = 27.6%) and week 9, n = 16 (for three components R2Y = 58.3%, Q2 = 32.1%). The R2Y value represents the goodness of fit of the model, and the Q2 value represents the predictability of the models. LCG rats are indicated by black squares and NCG rats by red triangles. Each data point represents one subject. Comp, component. t, component 1; t, component 2.