mRNA expression levels of genes involved in calcium-promoting mechanism as determined using real-time PCR. Transient receptor potential cation V6 (TRPV6) (A), Transient receptor potential cation V5 (TRPV5) (B), calcium-binding protein-D9k (CaBP-D9K) (C), plasma membrane Ca-ATPase (PMCA1b) (D). Note: control, normal group; model, low calcium group; HCaCO3, high dosage of CaCO3 group; HGCa, high dosage of calcium gluconate group; LCPPH + LCaCO3, low dosage of CPPH supplemented with low dosage of CaCO3 group; MCPPH + MCaCO3, model dosage of CPPH supplemented with model dosage of CaCO3 group; HCPPH + HCaCO3, high dosage of CPPH supplemented with high dosage of CaCO3 group; LCPPH-Ca, low dosage of CPPH-Ca group; MCPPH-Ca, model dosage of CPPH-Ca group; HCPPH-Ca, high dosage of CPPH-Ca group. Data are expressed as the mean ± SD (n = 10). One-way ANOVA with Tukey’s test. Different letters indicate significant effect with p < 0.05.