SOST and vitamin D deficiency: Zittermann et al. (2007) Calcitriol regulation of osteocyte sclerostin production is a factor in its actions on vascular calcification (Figure 3). Nguyen-Yamamoto et al. (2019) Osteocyte specific calcitriol deficiency blocked CKD stimulation of sclerostin levels, increased BMP2 in the skeleton, and increased CKD stimulated VC. Recent studies suggest that vitamin D deficiency in CKD induces reductions in aortic microRNA-145 stimulating osteogenic differentiation along with hyperphosphatemia (Figure 4). Carrillo-López et al. (2022).