Vitamin D: are all compounds equal?

Vitamin D is a pre-hormone essential for maintaining mineral homeostasis and also plays significant roles in bone, cardiovascular and renal health. Vitamin D deficiency is prevalent in the general population, and even more so in chronic kidney disease (CKD) patients, in which it contributes to the development and progression of mineral and bone disorder. The landscape of vitamin D treatment has evolved, with several analogues now available, each possessing distinct pharmacokinetic and pharmacodynamic properties, efficacies and safety profiles. This diversity allows for tailored, personalized approaches to treatment in CKD patients. This review aims to provide a comprehensive overview of vitamin D, including its natural sources and metabolism, and examines the main available pharmacological vitamin D products. Particular emphasis is placed on their application in CKD management, highlighting how these compounds can be strategically used to address both vitamin D deficiency and secondary hyperparathyroidism, while also acknowledging the ongoing debate about their impact on bone health and other clinical outcomes.