22-Oxacalcitriol

Agonists of the vitamin D receptor are used to suppress parathyroid hormone (PTH) synthesis and secretion in the treatment of hyperparathyroidism associated with renal failure.{21563} 22-Oxacalcitriol is an analog of calcitriol that, like calcitriol, is a receptor-active form of vitamin D3 which effectively blocks PTH synthesis.{22231,22230} First reported to avoid hypercalcemia, an undesirable side effect of calcitriol, prolonged treatment with 22-oxalcalcitriol can be calcemic in humans.{22231,22230} Analogs of calcitriol, including 22-oxacalcitriol, inhibit human keratinocyte proliferation while inducing differentiation and is beneficial in treating psoriasis.{22227,22226} 22-Oxacalcitriol also blocks the proliferation while inducing differentiation and apoptosis of certain tumor cells.{22229}