Test Directory

25-Hydroxyvitamin D2 and D3, Serum

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Updated Test Information:

Test Description
25-Hydroxyvitamin D2 and D3, Serum
Synonym(s)
25-Hydroxyvitamin D2 and D3
Test ID
25HDN
General Information
Useful for:
Diagnosis of vitamin D deficiency
Differential diagnosis of causes of rickets and osteomalacia
Monitoring vitamin D replacement therapy
Diagnosis of hypervitaminosis D
Specimen Type
Serum
Specimen Requirements
Red Top
Stability
Refrigerated (preferred) 14 days
Frozen 30 days
Ambient 7 days
Unacceptable Specimen Conditions
Gross hemolysis OK
Gross lipemia OK
Gross icterus OK
Methodology
Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS)
Estimated TAT
2-5 days
Testing Schedule
Monday-Friday
CPT Code(s)
82306
Minimum Sample Volume
0.25 mL
Reference Range

TOTAL 25-HYDROXYVITAMIN D2 AND D3 (25-OH-VitD)
<10 ng/mL (severe deficiency)*
10-19 ng/mL (mild to moderate deficiency)**
20-50 ng/mL (optimum levels)***
51-80 ng/mL (increased risk of hypercalciuria)****
>80 ng/mL (toxicity possible)*****

*Could be associated with osteomalacia or rickets

**May be associated with increased risk of osteoporosis or secondary hyperparathyroidism

***Optimum levels in the healthy population, patients with bone disease may benefit from higher levels within this range

****Sustained levels >50 ng/mL 25OH-VitD along with prolonged calcium supplementation may lead to hypercalciuria and decreased renal function

*****80 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 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-OHVitD is impaired or absent.

These reference ranges represent clinical decision values, based on the 2011 Institute of Medicine report, that apply to males and females of all ages, rather than population-based reference values. Population reference ranges for 25-OH-VitD vary widely depending on ethnic background, age, geographic location of the studied populations, and the sampling season. Population-based ranges correlate poorly with serum 25-OH-VitD concentrations that are associated with biologically and clinically relevant vitamin D effects and are therefore of limited clinical value.

Performing Lab
Mayo
LOINC Code(s)
49054-0, 1989-3, 62292-8