What is it?

Calcitriol or alfacalcidol are prescription forms of vitamin D.

Why did my doctor prescribe or recommend it?

Calcitriol or alfacalcidol are used to lower a hormone called parathyroid hormone or PTH. This hormone is released by the parathyroid glands in the neck and is often high in people with kidney disease. The purpose of PTH in the body is to control calcium and phosphate levels. We measure the level of PTH from a blood test. High levels of PTH for long periods of time can cause calcium to be removed from the bones and weaken them.

How does it work?

Calcitriol or alfacalcidol tell the parathyroid glands to stop making so much parathyroid hormone (PTH).

Calcitriol and alfacalcidol are different than the vitamin D you can buy over-the-counter. Over-the-counter vitamin D needs to be activated by the kidneys in order to work in the body. People with kidney disease may not be able to do this kidney activation so we prescribe calcitriol or alfacalcidol, which already have the kidney activation done.

How long will I be on it?

Prescription vitamin D is usually taken long-term to keep the parathyroid hormone (PTH) level under control. Do not stop taking unless you talk to your kidney doctor, nurse, dietitian or pharmacist.

What doses are recommended?

The dose is based on your blood test results. These capsules may be taken every day or three times per week. It is usually recommended to take these capsules at bed time. These capsules can be taken with or without food and should be swallowed whole.

What if I miss a dose?

If you miss a dose, take one as soon as you remember. If it is almost time for your next dose, skip the missed dose and go back to your regular schedule. Do not double up on doses or “catch up” by taking extra doses.

Are there any side effects?

Calcitriol or alfacalcidol may increase your calcium and phosphorus (phosphate) levels in your blood. We check your blood tests to make sure these do not go too high. It is important to follow any food recommendations from your kidney dietitian such as a low phosphate diet.