The University of Iowa (UIHC)
Department of Pathology
LABORATORY SERVICES HANDBOOK


Vitamin D, 25-Hydroxy
Order Code: VITD25
Epic Lab Code: LAB535
Order Form: A-1a Miscellaneous Request or Epic Req
  Commercial "Mail-out" Laboratory
6240 RCP
356-3527
Specimen:
Plasma
Collection Medium:
Plasma separator tube
Alternate
Collection Media:
Lavender top tube (EDTA), Light Green top tube (Lithium Heparin), Red 
top tube, Green top tube (Na Heparin), Pink top tube (EDTA sprayed)
Minimum:
Preferred Minimum: 1.0 mL plasma
Absolute Minimum: 0.3 mL plasma
Rejection Criteria:
Grossly hemolyzed or lipemic specimens.
Analytic Time:
4 working days
Reference Range:
Deficiency:  Less than 20 ng/mL
Insufficiency:  20-29 ng/mL
Optimum Level:  30-80 ng/mL
Possible Toxicity:  Greater than 80 ng/mL
Interpretive Data:
This is the appropriate screening test for routine assessment of 
vitamin D nutritional status.  This assay accurately quantifies the sum 
of vitamin D3, 25-Hydroxy and vitamin D2, 25-Hydroxy.  Optimum 
25-hydroxy vitamin D concentration is 35 ng/mL or higher.  For workup 
of hypercalcemia, vitamin D status in renal failure patients, and 
certain malignancies, "Vitamin D (1,25-dihydroxy)" may be indicated.
Methodology:
Chemiluminescent Immunoassay
CPT Code:
82306

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Updated: 09/24/2009

Note: The information contained in this handbook is for use by personnel of University of Iowa Health Care. No other use is implied or intended.