Vitamin D 25-Hydroxy (Calcidiol) Blood Test

The vitamin D 25-hydroxy (calcidiol) blood test is used to measure the level of vitamin D in your body. Vitamin D is important for maintaining strong bones, supporting immune function, and regulating cell growth.

Low levels of vitamin D can lead to issues such as osteoporosis, increased risk of fractures, and weakened immune system. Conversely, high levels of vitamin D can lead to toxicity and can cause symptoms such as nausea, vomiting, weakness, and kidney damage.

The test is usually ordered when there is a concern about a vitamin D deficiency or toxicity. It is typically performed as part of a routine check-up or if you are experiencing symptoms such as bone pain, muscle weakness, or fatigue.

The test involves drawing blood from a vein and measuring the levels of 25-hydroxy vitamin D. Results are typically reported in nanograms per milliliter (ng/mL) or nanomoles per liter (nmol/L).