LRP2 and chronic kidney disease: If 1α,25(OH)2D3 promotes megalin expression, and if megalin is essential for the renal delivery of 25OHD3, then diminished renal 1α,25(OH)2D3 synthesis, such as in chronic kidney disease (CKD) (Bosworth and de Boer, 2013), would reduce renal access of 25OHD3 and result in further reductions in 1α,25(OH)2D3 synthesis and progressively deteriorating vitamin D status.