A 56-year-old man with end-stage renal disease comes to the physician for a follow-up examination. 8 months ago, he received a cadaveric renal transplant. Current medications are tacrolimus, nifedipine, metoprolol, and vitamin D. Laboratory findings show:
Hemoglobin 14 g/dL
Blood urea nitrogen 20 mg/dL
Creatinine 1.2 mg/dL
Calcium 11.5 mg/dL
Which of the following is the most likely explanation for these findings?
Acquired vitamin D resistance
Drug adverse effect
Glandular hyperplasia
Hypervitaminosis D
Vitamin D resistance
