The results were analyzed using SPSS 17.0 software.



SPSS
PCR-RFLP method was used to genotype 3 SNPs of the VDR gene (rs1544410, rs7975232 and rs731236). 
PCR-RFLP method
ELISA method was used to detect the amount of 1,25(OH)2D3 in the plasma. 
ELISA method