Within the PCa tissue samples in the abovementioned randomized clinical trial by Wagner et al. [97], the expression of CYP24A1—as a characteristic indicator of VDR and calcitriol function—did not statistically differ between the subdivided samples regarding tertile calcitriol concentrations in the ranges of 15–24, 25–33, and 34–79 pmol/kg [21]. Here, CYP24A1 is linked to posterior cortical atrophy.