Vitamin D

Vitamin D testing measures the level of this essential substance in your blood. It is used to diagnose vitamin D deficiencies or to monitor treatment for a known deficiency.

The main function of vitamin D is to aid in the absorption of calcium during bone formation. Maintaining adequate levels of vitamin D supports healthy bones. In addition, vitamin D has anti-inflammatory and other properties that play a role in maintaining normal muscle, immune, and nervous system functions.

Vitamin D blood testing can be used to check your levels so a deficiency can be corrected. Less commonly, vitamin D testing may be used to detect vitamin D toxicity, a condition in which there is an excess of vitamin D in the body.