Test Results For:
Vitamin D (25(OH))
Test Overview
- Test Name
-
Vitamin D (25(OH))
- Test Code
- VITD
Short Description
Vit D
Test Name
Vitamin D (25(OH))
Test Code
VITD
Category
Immunoassay
TAT
Main Lab:
6,
Hour(s)
Family Site:
<6hrs, <8hrs
Specimen(s)
1 x Venous blood - 5 mL Tube - Gold - SST-Serum Separator Tube
Specimen Type
SST-Serum Separator Tube
Specimen Format
Tube
Specimen Colour
Gold
Specimen Volume
5 mL
Sampling Order
2
Origin
Venous blood
Collection Time after baseline
-
Transport Temperature
2-8°C
Accepted Other Specimens
Serum
TAT
Main Lab:
6,
Hour(s)
Family Site:
<6hrs, <8hrs
Test Stability
Room Temp:
3 Hour(s)
2–8°C:
6 Hour(s)
Methodology
-
Specimen Type
SST-Serum Separator Tube
Other Type of Specimen Accepted
Serum
Delay before pre-treatment
3
Transport temperature
2-8°C
Test stability at room temperature
3 Hour(s)
Test stability at 2–8°C
6 Hour(s)
Haemolysis interference
No
Clinical Interest
The measurement of 25-hydroxyvitamin D (25 (OH)D) is indicated to confirm deficiency in cases of musculoskeletal symptoms (bone pain, muscle weakness, atypical fractures, rickets, or osteomalacia), or in at-risk populations: elderly individuals, people with pigmented skin, low sun exposure, obesity (BMI > 30), malabsorption (celiac disease, IBD), chronic renal or hepatic failure, pregnant or breastfeeding women.
It is routinely performed as part of osteoporosis screening, particularly in cases of fragility fractures or before starting anti-osteoporotic treatment. It also helps distinguish between secondary hyperparathyroidism (related to vitamin D3 deficiency, with high PTH and low 25(OH)D) and primary hyperparathyroidism. Finally, it is used for therapeutic monitoring during supplementation, especially at high doses, or in patients receiving interfering treatments (antiepileptics, glucocorticoids, antiretrovirals).
The interpretation thresholds used are:
- deficiency (< 20 ng/mL or < 50 nmol/L), insufficiency (20–29 ng/mL or 50–74 nmol/L),
- and a therapeutic target between 30 and 50 ng/mL (75–125 nmol/L).
A level above 100 ng/mL (> 250 nmol/L) exposes the patient to a risk of hypercalcemia.
Clinical Information Required
-
Patient Collection Note
-
LOINC Code
89-3, 1989-3,
Outwork
No