Test Code VITD Vitamin D, 25-OH, Total
Additional Codes
Epic: LAB8614
Specimen Required
Specimen Type: Serum
Collection Container/Type
Preferred: Serum gel
Acceptable: Green top (Lithium heparin)
Submission Container/Tube: Plastic
Specimen Volume: 3 mL
Collection Instructions: Centrifuge and separate cells after clot formation and within 4 hours of collection.
Specimen Minimum Volume
0.2 mL
Specimen Stability
Room temperature: 3 days
Refrigerated (on gel): 3 days
Refrigerated (off gel): 12 days
Frozen: 3 months
Reference Range
<20 ng/mL (deficiency)
20 - 30 ng/mL (insufficiency)
≥ 30 ng/mL (Optimal)
Vitamin D, 25-OH, Total: Testing performed using ABBOTT Architect chemiluminescent microparticle immunoassay methodology. Method-dependent minor difference may exist based on the test platform used.
Rejection Due To
Unlabeled, mislabeled, wrong tube type, hemolyzed, QNS, exceeds specimen stability requirements.
Report Available
Same day
Clinical Significance
Vitamin D is a fat-soluble steroid prohormone mainly produced photochemically in the skin from 7-dehydrocholesterol.
Two forms of vitamin D are biologically relevant – Vitamin D3 (Cholecalciferol) and Vitamin D2 (Ergocalciferol). Both Vitamins D3 and D2 can be absorbed from food, with Vitamin D2 being an artificial source, but only an estimated 10-20% of vitamin D is supplied through nutritional intake. Vitamins D2 and D3 can be found in vitamin supplements. Vitamin D is converted to the active hormone 1,25-(OH)2-vitamin D(calcitriol) through two hydroxylation reactions. The first reaction occurs in the liver, converting Vitamin D into 25-OH vitamin D. The second reaction, occurring in the kidneys, converts 25-OH vitamin D into the biologically active 1,25(OH)2-vitamin D. The major storage form of vitamin D is 25-OH vitamin D(half-life of 2-3 weeks) and is present in the blood at up to 1,000 fold higher concentration compared to the active 1,25(OH)2-vitamin (half-life of 4 hours).This assay measures 25-OH Vitamin D.
Measurement of Vitamin D status provides opportunities for preventive and therapeutic interventions for Vitamin D insufficiencies and deficiencies.
Vitamin D deficiency is a cause of secondary hyperparathyroidism, rickets, osteoporosis, osteomalacia. Reduced 25-OH vitamin D concentrations in blood have been associated with an increasing risk of chronic diseases, including common cancers, autoimmune or infectious diseases or cardiovascular problems.
Method Name
Chemiluminescent microparticle immunoassay (CMIA)
Aliases
25-Hydroxy D2
25-Hydroxy D3
25-Hydroxy Vitamin D
25-Hydroxycholecalciferol
25-Hydroxyergocalciferol
25-OH Vitamin D
Day(s) Performed
Daily
LOINC
62292-8