p Calcitriol is a man-made active form of vitamin D. Most people get enough vitamin D from exposure to the sun and from fortified food products (e.g., dairy products, vitamins). Vitamin D helps control parathyroid hormone and the levels of certain minerals (e.g., calcium, phosphorus) that are needed for building and keeping strong bones. Before regular vitamin D can be used by the body, it needs to be changed to the active form by the liver and kidneys. Calcitriol is used in patients with kidney disease who can't make enough of the active form of Vitamin D. This medication is also used to prevent and treat certain types of calcium/phosphorus/parathyroid problems that can happen with long-term kidney dialysis or hypoparathyroidism. Calcitriol is usually used along with specific diet recommendations and sometimes other medications. /p