hydroxyprogesterone caproate + vitamin d3

Hydroxyprogesterone caproate + vitamin d3 is a combination product consisting of hydroxyprogesterone caproate, a synthetic progestin, and vitamin D3 (cholecalciferol), a fat-soluble secosteroid. Hydroxyprogesterone caproate acts as a selective agonist of the progesterone receptor, mimicking endogenous progesterone to help maintain pregnancy and reduce the risk of preterm birth in women with singleton pregnancies and prior spontaneous preterm delivery[5][7][8]. Vitamin D3 is essential for calcium homeostasis and bone metabolism; it also plays roles in immune modulation. The rationale for combining these agents may be to address both hormonal support for pregnancy maintenance (via progestin) and maternal/fetal bone health or immune function (via vitamin D3), though no specific combination product with this exact formulation appears widely marketed or approved.