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Epic Test Code LAB3107 Vitamin D, Total Nutritional (In-House)

Performing Location(s)

BMC

Synonyms

25-Hydroxy D2

25-Hydroxy D3
25-Hydroxy Vitamin D
25-Hydroxycholecalciferol

25-Hydroxyergocalciferol

25-OH Vitamin D

D2
D3
Vitamin D Assay

Specimen Type

Serum

Preferred Container

Gold or Red top tube

Blood Tube Draw Volume

Min 50% draw volume  

Minimum Volume to Submit for Testing

1.0 mL Serum

  • Multiple test can be performed from this volume. For question please contact the lab at 547-3975.  

Storage Requirements

Sample tubes should be centrifuged within 2 hours of collection 

Gold tops DO NOT ALIQUOT

Aliquot Red tops

See Causes of Rejection for temperature requirements.

Transportation Needs

 Deliver specimen to laboratory within 1 hour of collection if unspun. If not possible see "storage Requirements". 

Causes for Rejection

Mislabeled or unlabeled specimen
Less than 50% draw for Vacutainer tubes

> 7 day Refrigerated
> 3 days Room Temperature
> 1 year Frozen
Hemolysis > 50 mg/dL HgB
Lipemia > 3280 mg/dL Trig
Bilirubin > 40 mg/dL Bili
EDTA,Citrate,NaF,Oxalate
TP >9.0 g/dL

Limitations

Heterophilic antibodies in human serum can react with reagent immunoglobulins. Patients routinely exposed to animals or animal serum products can be prone to this interferent and anomalous values may be observed.

 

Hemolyzed samples may be falsely depressed.

 

Vitamin D status may be variable depending upon the patients D Binding Protein (DBP) concentration and/or its isoforms. DBP values are altered in pregnancy, dialysis, sepsis, and significant organ dysfunction. If any of the above conditions apply, consider retesting at a later date or by a different method (eg. LC-MS/MS).

Reference Values

Result Units Interpretation
< 8 - 19 ng/mL

Deficiency*
20 - 30 ng/mL

Insufficient
31 - 100 ng/mL Sufficient **
> 100 ng/mL Toxicity ***

 

*Could be associated with osteomalacia or rickets or increased risk of osteoporosis or secondary hyperparathyroidism
**Optimum levels in the normal population 
***Most patients with toxicity have levels >150 ng/mL. Patients with renal failure can have very high 25-OH-VitD levels without any signs of toxicity as renal conversion to the active hormone 1,25-OH-VitD is impaired or absent.

Available STAT

No

Days of Analysis

M-F

Additional Information

Additional Information:

Vitamin D assays measure the 25 hydroxy metabolites of vitamin D: 25 (OH) Vitamin D2 and 25 (OH) Vitamin D3. It is the sum of these two metabolites that most reliably reflects a patient’s vitamin D status. Although there is only a minor difference in molecular structure, the two forms have been shown to have very different efficacy in suplementation and treatment of bone density. Supplementation with D3 is more effective than D2.

 

There are two types of vitamin D: vitamin D2 (ergocalciferol) from plants, and vitamin D3 (cholecalciferol) from sunlight, and also from fatty fish as herring and mackerel.

 

Vitamin D assays measure metabolites of vitamin D2 and vitamin D3: 25 (OH) vitamin D2 and 25 (OH) Vitamin D3. There are other metabolites of vitamin D; however it is the sum of 25 (OH) vitamin D2 and 25 (OH) Vitamin D3 levels (total vitamin D) that most reliably reflects a patient’s vitamin D status.

The BMC assay detects equimolar amounts of D2 and D3. It is traceable to the gold standard 25(OH) Vitamin D reference measurement procedure.

Methodology

Beckman AU/Dx Series

CPT Code

82306

Last Updated

29-NOV-24 MS