PTH and chronic kidney disease: 1,25 (OH)2 Vitamin D3 supplementation, commonly employed to suppress parathyroid hormone in CKD, has also been implicated as a cause of VC.[8] Other promoters (such as bone morphogenetic protein and osteocalcin) and inhibitors (such as matrix Gla protein and fetuin-A) of VC have been identified.[9–12] While their role in clinical management remains to be established, these proteins are potential therapeutic targets in CKD-associated VC.