Vitamin D, 25 Hydroxy

Overview

  • EPIC Code:
  • IMO70
  • Soft Test Code:
  • VD251
Alternate Names
  • 25 Hydroxy Vitamin D
  • 25-Hydroxy D2
  • 25-Hydroxy D3
  • 25-Hydroxy Vitamin D
  • 25-Hydroxycholecalciferol
  • 25-Hydroxycholecalciferol (25OHD3)
  • 25-Hydroxyergocalciferol
  • 25-Hydroxyergocalciferol (25OHD2)
  • 25-Hydroxyvitamin D2
  • 25-Hydroxyvitamin D3
  • 25-OH D2
  • 25-OH D3
  • 25-OH-D2
  • 25-OH-D3
  • 25HDN
  • 25ODH
  • Calcidiol
  • Calcifidiol
  • Cholecalciferol
  • Colecalciferol
  • D2
  • D2 Vitamin
  • D3
  • D3 Vitamin
  • Ergocalciferol
  • Vit D
  • Vit D 25 OH
  • Vitamin D
  • Vitamin D 25 Hydroxy
  • Vitamin D, 25 OH
  • Vitamin D, 25 OH Total, D2, D3
  • Vitamin D, 25-Hydroxy
  • Vitamin D, 25-OH
  • Vitamin D, Total
  • Vitamin D2
  • Vitamin D2, 25-hydroxy
  • Vitamin D3
  • Vitamin D3, 25-hydroxy
Clinical Significance

Vitamin D is obtained from food and supplements or made in the skin by exposure to sunlight.  25-OH Vitamin D is formed from these Vitamin D sources and stored in the liver.  25-OH Vitamin D is then changed to its active form, 1,25-dihydroxy Vitamin D, in the kidney.  1,25-dihydroxy Vitamin D keeps normal levels of calcium and phosphate in the blood through its actions on the intestines, kidneys, and bones. 
 
The most reliable clinical indicator of Vitamin D status is 25-OH Vitamin D because serum or plasma levels reflect the body’s storage levels of Vitamin D.  25-OH Vitamin D levels correlate with the clinical symptoms of Vitamin D deficiency.
 
Abnormal 1,25-dihydroxy Vitamin D levels may be seen in primary hyperparathyroidism, physiologic hyperparathyroidism secondary to low calcium or vitamin D intake, hypoparathyroidism, and chronic renal failure.  1,25-dihydroxy Vitamin D levels may be needed to adequately assess Vitamin D status in the presence of renal disease.
 
25-OH Vitamin D level is performed by PHL and should be ordered as test code VD251.  1,25-dihydroxy Vitamin D is performed by Quest Diagnostics and should be ordered as test code VITD2.


Specimen Collection & Preparation

Patient Preparation

12 hours fasting is preferred but not required

Patient should discontinue taking Biotin, Vitamin B7, or Vitamin H 48 hours before getting blood drawn.


Specimen Requirements:

-OR-

1.0 mL Serum in a SST Gold Top Tube
Minimum Volume:
0.2 mL Serum*

* This volume does not allow for repeat testing

Rejection Criteria:

Plasma from/in a PST Mint Green Top Tube - Li Heparin


Transport and Storage:
  • Ambient (18-24°C): 8 Hours
  • Refrigerated (2-8°C): 4 Days
  • Frozen (-20° C or colder): 24 Weeks

    Avoid storage in frost-free freezers to avoid repeated freeze/thaw cycles

Clinical Interpretation

Reference Range:

30 - 100 ng/mL


Test Comments:

Values < 30 ng/mL:

25-OH Vitamin D levels below 20 ng/mL are indicative of a deficiency. Levels between 20 and 30 ng/mL are indicative of an insufficiency.

Patients taking vitamin supplements containing high doses of biotin (> 5 mg/day) may have falsely increased test results generated.


Methodology:
  • Enzyme Immunoassay (EIA)
Clinical Significance

Vitamin D is obtained from food and supplements or made in the skin by exposure to sunlight.  25-OH Vitamin D is formed from these Vitamin D sources and stored in the liver.  25-OH Vitamin D is then changed to its active form, 1,25-dihydroxy Vitamin D, in the kidney.  1,25-dihydroxy Vitamin D keeps normal levels of calcium and phosphate in the blood through its actions on the intestines, kidneys, and bones. 
 
The most reliable clinical indicator of Vitamin D status is 25-OH Vitamin D because serum or plasma levels reflect the body’s storage levels of Vitamin D.  25-OH Vitamin D levels correlate with the clinical symptoms of Vitamin D deficiency.
 
Abnormal 1,25-dihydroxy Vitamin D levels may be seen in primary hyperparathyroidism, physiologic hyperparathyroidism secondary to low calcium or vitamin D intake, hypoparathyroidism, and chronic renal failure.  1,25-dihydroxy Vitamin D levels may be needed to adequately assess Vitamin D status in the presence of renal disease.
 
25-OH Vitamin D level is performed by PHL and should be ordered as test code VD251.  1,25-dihydroxy Vitamin D is performed by Quest Diagnostics and should be ordered as test code VITD2.


Production Schedule

Sites Performed
  • Parkview Regional Medical Center
Days Performed
Sunday
Monday
Tuesday
Wednesday
Thursday
Friday
Saturday
Departments
  • Chemistry
Turn Around Time

Same Day/1 to 2 days


Coding & Compliance

CDM

01421010


CPT Coding

82306


Medical Necessity May Apply
Medical Necessity Documentation

ICD 10 Diagnosis codes that support medical necessity.

Vitamin D Assay Testing