Pathology tests database

Sample and container requirements

Serum

Minimum volume required

Special requirements

None

Patient preparation

None

Sample viability

Turnaround time

This assay is run throughout the day and night. The in-lab turnaround time is normally less than 24 hours.

Reference range

<15 nmol/L: Severe vitamin D deficiency 15 – 25 nmol/L: Vitamin D deficiency 25 – 50 nmol/L: Vitamin D insufficiency ≥50 nmol/L: Adequate vitamin D status Signs of vitamin D toxicity maybe seen at levels greater than 250 nmol/L

Clinical guidance

Vitamin D plays a major role in calcium homeostasis. It increases calcium absorption from the gut, promotes bone mineralisation by provision of calcium, reduces 1a hydroxylase activity in the kidneys and reduces PTH production by the parathyroid glands. Vitamin D is measured by the Abbott 2nd generation 25-OH vitamin D immunoassay. Paediatric samples (<10 years) and patients identified as being on vitamin D2 supplements will be analysed by mass spectrometry for vitamin D. Routine measurement of vitamin D is not recommended in asymptomatic patients. There is a minimum retesting interval for vitamin D of 3 months. Please refer to LabTestsOnlineUK to learn more about vitamin D. https://labtestsonline.org.uk/tests/vitamin-d

Notes