Short-term vitamin D receptor activation increases serum creatinine due to increased production with no effect on the glomerular filtration rate.

Vitamin D receptor activation has been associated with increased serum creatinine and reduced estimated glomerular filtration rates, raising concerns that its use may be detrimental to kidney function. Here we studied the effect of vitamin D receptor activation on serum creatinine, creatinine generation, and its clearance. We measured baseline serum creatinine and 24-h urine creatinine in 16 patients with chronic kidney disease.