Lab Information Manual

Laboratory:

Clinical Biochemistry (SPECIAL CHEMISTRY)

Test Name:

VITAMIN D (25-HYDROXY) - (S)

Test Code: VD25

Clinical Information:

Test Indications: Screening for vitamin D deficiency in healthy individuals is not recommended.

25-OH vitamin D should only be ordered in the following clinical conditions:
- Metabolic bone disease (recurrent fractures, rickets, osteomalacia, osteopenia, osteoporosis).
- Abnormal blood calcium, magnesium, or phosphate concentrations.
- Parathyroid disease
- Malabsorption syndrome (celiacs disease, cystic fibrosis, small bowel surgery, medications that interfere with vitamin D absorption such as cholestyramine, orlistat, etc).
- Anticonvulsant agents.
- Chronic renal disease.
- Chronic liver disease.
- Intake of high doses of vitamin D combined with symptoms suggestive of hypervitaminosis D

See F10-50-45D Approved Physicians for Specialist Endocrinology Requisition

Choose Wisely Manitoba Clinical Practice Change - Vitamin D 25-OH_Effective Feb 1, 2016

Clinical Practice Change - Endocrine Testing and Specialized Endocrinology Requisition Update 15-May-24

Clinical Practice Change General-Endocrinology-Requisition-and-Endocrine-Testing-Update 15-May-24

Collection Devices:

Preferred Device:	1 - Serum Tube(s), NO GEL - Full Tube Collection Serum Tube(s), NO GEL - Full Tube Collection Manufacturer: Becton Dickinson Catalogue #: 366430
Alternate Device:	1 - Microtainer(s) - Plain Serum, NO GEL (0.5 mL) to fill line Microtainer(s) - Plain Serum, NO GEL (0.5 mL) to fill line Manufacturer: Becton Dickinson & Company Catalogue #: 365963

Alternate Device: Serum Separator (SST) Tube(s) - Full Tube Collection
Plasma is not acceptable.

Specimen Required:

Serum: 0.5 mL

Pediatric Serum: 0.25 mL

Special Processing: Spin down and separate serum within 1 hour of collection.
Specimen Stability:
Ambient: 72 hours
Refrigerated: 5 days
Frozen: 6 months

Referral:

Specimen Type: Serum
Shipping & Storage: Store and ship frozen.
Testing Laboratory (MB): MS5-Health Science Centre

Requisition:

_SH General Endocrinology Requisition (R250-10-76)

_SH Specialized Endocrinology Requisition (R250-10-77)

Reference Values:

Category	Result (nmol/L)
Deficiency: Insufficiency: Sufficiency: Potentially harmful:	<25 27 – 74 75 – 249 ≥ 250

Method of Analysis: DiaSorin Liaison XL chemiluminescent competitive immunoassay (effective August 8, 2023)

Reference Value Document Links: Osteoporosis Canada Recommendations
- Hanley DA, Cranney A, Jones G, Whiting SJ, Leslie WD; Guidelines Committee of the Scientific Advisory Council of Osteoporosis Canada. Vitamin D in adult health and disease: a review and guideline statement from Osteoporosis Canada (summary). CMAJ. 2010 Sep 7;182(12):1315-9. doi: 10.1503/cmaj.091062.

Availability:

Within 1 Week