About This Test
Vitamin D is essential for bone health and many metabolic processes. The body derives it from sunlight and food sources. Many people do not get enough sunlight or do not consume enough vitamin D rich foods. This test is important to determine if you need vitamin D supplementation or if your current supplementation is effective.
25-Hydroxyvitamin D (25OHD) is the major circulating form of vitamin D and the precursor of the active form (1,25-dihydroxyvitamin D). Because of its long half-life, measurements are useful for assessing vitamin D status in patients. This test measures 25OHD using liquid chromatography, the most accurate test to determine Vitamin D blood levels.