St. Luke's Hospital
Main Number: 314-434-1500 Emergency Dept: 314-205-6990 Patient Billing: 888-924-9200
Find a Physician Payment Options Locations & Directions
Follow us on: facebook twitter Mobile Email Page Email Page Print Page Print Page Increase Font Size Decrease Font Size Font Size
America's 50 Best Hospitals
Meet the Doctor
Spirit of Women
Community Health Needs Assessment
Home > Health Information

Multimedia Encyclopedia

    Print-Friendly
    Bookmarks

    25-hydroxy vitamin D test

    25-OH vitamin D test; Calcidiol; 25-hydroxycholecalciferol test

    The 25-hydroxy vitamin D test is the most accurate way to measure how much vitamin D is in your body.

    In the kidney, 25-hydroxy vitamin D changes into an active form of the vitamin. The active form of vitamin D helps control calcium and phosphate levels in the body.

    This article discusses the blood test used to measure the amount of 25-hydroxy vitamin D.

    How the Test is Performed

    A blood sample is needed. For information on how this is done, see: Venipuncture

    How to Prepare for the Test

    Usually you will not need to fast. However, this depends on the laboratory on the testing method used.

    How the Test Will Feel

    When the needle is inserted to draw blood, some people feel moderate pain, while others feel only a prick or stinging sensation. Afterward, there may be some throbbing.

    Why the Test is Performed

    This test is done to determine if you have too much or too little vitamin D in your blood.

    Normal Results

    The normal range is 30.0 to 74.0 nanograms per milliliter (ng/mL).

    The examples above are common measurements for results of these tests. Normal value ranges may vary slightly among different laboratories. Some laboratories use different measurements ortest different samples.Talk to your doctor about the meaning of your specific test results.

    What Abnormal Results Mean

    Lower-than-normal levelscan be due toa vitamin D deficiency, which can result from:

    • Lack of exposure to sunlight
    • Lack ofenough vitamin D in the diet
    • Liver and kidney diseases
    • Poor food absorption
    • Use of certain medicines, including phenytoin, phenobarbital, and rifampin

    Low vitamin D levels are more common in African-American children (especially in the winter), as well as in infants who are breastfed only. Low vitamin D levels have also been associated with an increased risk of developing cancer. For more information, see the article on vitamin D deficiency.

    Higher-than-normal levelsmay be due toexcess vitamin D, a condition called hypervitaminosis D.

    Risks

    Veins and arteries vary in size from one patient to another and from one side of the body to the other. Obtaining a blood sample from some people may be more difficult than from others.

    Other risks associated with having blood drawn are slight but may include:

    • Excessive bleeding
    • Fainting or feeling light-headed
    • Hematoma (blood accumulating under the skin)
    • Infection (a slight risk any time the skin is broken)

    References

    Weng FL, Shults J, Leonard MB, Stallings VA, Zemel BS. Risk factors for low serum 25-hydroxyvitamin D concentrations in otherwise healthy children and adolescents. Am J Clin Nutr. 2007;86(1):150-158.

    Lappe JM, Travers-Gustafson D, Davies KM, Recker RR, Heaney RP. Vitamin D and calcium supplementation reduces cancer risk: results of a randomized trial. Am J Clin Nutr. 2007;85(6):1586-1591.

    Specker BL, Valanis B, Hertzberg V, Edwards N, Tsang RC. Sunshine exposure and serum 25-hydroxyvitamin D concentrations in exclusively breast-fed infants. J Pediatr 1985;107(3):372-376.

    BACK TO TOP

    • Blood test

      illustration

      • Blood test

        illustration

      A Closer Look

        Self Care

          Tests for 25-hydroxy vitamin D test

          Review Date: 7/19/2012

          Reviewed By: Shehzad Topiwala, MD, Chief Consultant Endocrinologist, Premier Medical Associates, The Villages, FL. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M. Health Solutions, Ebix, Inc.

          The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. © 1997- A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.
          adam.com

          A.D.A.M. content is best viewed in IE9 or above, Fire Fox and chrome browser.


          Back  |  Top
          About Us
          Contact Us
          History
          Mission
          Locations & Directions
          Quality Reports
          Annual Reports
          Honors & Awards
          Community Health Needs
          Assessment

          Newsroom
          Services
          Brain & Spine
          Cancer
          Heart
          Maternity
          Orthopedics
          Pulmonary
          Sleep Medicine
          Urgent Care
          Women's Services
          All Services
          Patients & Visitors
          Locations & Directions
          Find a Physician
          Tour St. Luke's
          Patient & Visitor Information
          Contact Us
          Payment Options
          Financial Assistance
          Send a Card
          Mammogram Appointments
          Health Tools
          My Personal Health
          mystlukes
          Spirit of Women
          Health Information & Tools
          Clinical Trials
          Health Risk Assessments
          Employer Programs -
          Passport to Wellness

          Classes & Events
          Classes & Events
          Spirit of Women
          Donate & Volunteer
          Giving Opportunities
          Volunteer
          Physicians & Employees
          For Physicians
          Remote Access
          Medical Residency Information
          Pharmacy Residency Information
          Physician CPOE Training
          Careers
          Careers
          St. Luke's Hospital - 232 South Woods Mill Road - Chesterfield, MO 63017 Main Number: 314-434-1500 Emergency Dept: 314-205-6990 Patient Billing: 888-924-9200
          Copyright © St. Luke's Hospital Website Terms and Conditions  |  Privacy Policy  |  Patient Notice of Privacy Policies PDF Sitemap St. Luke's Mobile