Figure 2 Calcitriol uptake study by B16–F10 cells by HPLC. (A) Detection of calcitriol content after time-dependent treatment in B16–F10 cells and medium. In the medium, calcitriol content was detected at 0 and 30 min. Although low, calcitriol was still detected at 60 and 120 min, while in the cell, the calcitriol content was detected at 30 and 60 min. (B) Compilation of representative peak curve HPLC of control baseline at 0 min, 30 min, 60 min, and 120 min showed calcitriol content detection inside the medium. (C) Compilation of representative peak curve HPLC of control baseline at 0 min, 30 min, 60 min, and 120 min showed calcitriol content detection inside the medium.