Rowland et al.'s study of African Americans and Whites showed that low calcium intake (<604 mg/day) was inversely related to PCa risk among men with the VDR Cdx2 GG genotype that has been linked to low calcium absorption 42.It is possible therefore, that the increased risk observed in this study may be related to factors such as the genetic variation in CaSR genes that control serum calcium levels 43. This evidence concerns the gene CDX2 and posterior cortical atrophy.