Vitamin D (25- Hydroxyvitamin D) - Black Country Pathology Services

Investigation Name:Vitamin D (25- Hydroxyvitamin D)

Alias or Abbreviation:Vitamin D, 25-hydroxyvitamin D3, 25-hydroxyvitamin D2

Accreditation:UKAS Accredited ISO15189:2022, on scope

Intro:

Vitamin D plays an important role in bone metabolism and calcium homeostasis. It may have other roles in immune modulation and development of different disease states. Vitamin D occurs in two forms, cholecalciferol (vitamin D3), which is produced in the skin by action of UV radiation and is present in dairy productions and egg yolk, and ergocalciferol (vitamin D2), a semi-synthetic form, present in foods fortified with vitamin D.

Vitamin D deficiency causes rickets in children and osteomalacia in adults, which may present with bone pain, tenderness and myopathy. Individuals with low exposure to sunlight are particularly at risk of vitamin D deficiency, particularly if compounded by dietary deficiency/malabsorption. Vitamin D excess usually occurs as a result of supra-physiological supplementation and may lead to hypercalcaemia and metastatic calcification.

When monitoring treatment for vitamin D deficiency, it is preferable to measure both 25-hydroxyvitamin D3 and D2, as vitamin D2 is less potent, and patients may respond more slowly than expected to treatment. Furthermore, many immunoassay methods for total 25-hydroxyvitamin D significantly under-recover 25-hydroxyvitamin D2.

Pathology Laboratory:Clinical Chemistry/ Biochemistry

Requestable Seperately?No

Units:nmol/L

Minimum Sample Volume:For internal work (immunoassay method): 1 mL.
For external work (mass spectrometry method): 250 µL erum/plasma preferred, absolute minimum: 75 µL

Expected Turnaround Time:7 working days

Sample Type:

Serum (Gold top), lithium heparin or EDTA plasma

Complex Reference Range:<25 nmol/L Vitamin D deficient
25-50 nmol/L Vitamin D insufficient
50.1-220 nmol/L Vitamin D sufficient
>220 nmol/L Increased risk of vitamin D toxicity

Referred to Another Laboratory?No

Storage Requirements:Store separated plasma/serum at 4°C prior to dispatch.

Posting Address / Requirements:1st class post at ambient temperature
Sandwell Health Campus
Specialist Chemistry
Pathology Department
Lyndon B71 4HJ

NPEX / PDF Reporting Available:NPEX and PDF reporting available.

EQA Scheme:UK NEQAS for Vitamin D

Further information:Please note that referred in work only is analysed by mass spectrometry.
Internal BCPS samples are analysed for total 25-hydroxyvitamin D by immunoassay on the Architect Alinity analysers.

Lead Contact Details:Helen Duce, Principal Clinical Scientist,
Email: h.duce@nhs.net

Email Address For Chasing Results:rwh-tr.bcpsspecialistchemistryenquiries@nhs.net

Site Sample Tested:Sandwell Health Campus

Cost:Please email: bcpspathology.info@nhs.net for further details

Contact Number:Tel: 0121 507 5162