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Test Code LAB535 Vitamin D, 25-Hydroxy

Additional Codes

VIT D25

Notes:

If the patient is supplemented with Ergocalciferol (Vitamin D2) and the result is <25 ng/mL, LC-MS/MS test is recommended since it may be better suited for Vitamin D2 measurement.

Collection:

Specimen: Blood 

Container: SST or Red Top.

Specimen Volume: 6 mL; Minimum 4 mL

 

Pediatric Collection:

Two Gold or Red Top microtainer filled to 600 uL.

Stability:

Once serum is separated from cells:

 

Ambient: 8 Hours

Refrigerated (preferred): 1 Week

Frozen: 2 Weeks

Turnaround Time (TAT):

STAT: 2 HOURS

Routine: 4 HOURS

Test Availability:

Daily / 24 Hours 

Performing Laboratory Section:

Chemistry / UMC MAIN LABORATORY

Reference Interval:

25.0 - 80.0 ng/mL

 

Interpretive Data:

Value Interpretation
<10 ng/mL Severe Deficiency - Could be associated with osteomalacia or rickets
10 - 24 mg/mL Mild to Moderate Deficiency - May be associated with increased risk of osteoporosis or secondary hyperparathyroidism.
25 - 80 ng/mL Optimum level - Optimum level in the normal population
>80 ng/mL Toxicity Possible -  80.0 ng/mL is the lowest reported level associated with toxicity in patients without primary hyperparathyroidism who have normal renal function. Most patients with toxicity have levels >150.0 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.