We investigated whether @ candidate single nucleotide polymorphisms ( SNPs ) in vitamin D and calcium pathway genes ( GC , DHCR@ , CYP@R@ , CYP@B@ , CYP@A@ , VDR , and CASR ) are associated with -LSB- @ ( OH ) D -RSB- or modify the increase in -LSB- @ ( OH ) D -RSB- from vitamin D@ supplementation .