< Return to all Tests

Test Category: Specialist Biochemistry

Investigation Name:Blood spot 25-Hydroxyvitamin D

Alias or Abbreviation:Vitamin D, 25-hydroxyvitamin D3, 25-hydroxyvitamin D2, direct to the public blood spot service.

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.
25-hydroxyvitamin D3 and D2 may be measured in blood spots collected using capillary blood rather than serum. This means that samples may be collected by individuals and renders samples more convenient for postage to the laboratory.

Pathology Laboratory:Mass Spec Laboratory

Requestable Seperately?Yes

Units:nmol/L

Expected Turnaround Time:14 working days

Sample Type:

Blood spot collected onto blood spot device/Guthrie card

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

Collection Conditions / Other Information:Please note blood spot 25-hydroxyvitamin D measurement is only performed for referred in or direct to the public work. If you wish to order a blood spot vitamin D test kit, please go to our ordering website: https://www.vitamindtest.org.uk/

Referred to Another Laboratory?No

Storage Requirements:Store blood spots at room temperature or 4 °C prior to dispatch

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

NPEX / PDF Reporting Available:yes

EQA Scheme:None available. Comparisons are regularly made between capillary blood spot and serum 25-hydroxyvitamin D measurements.

Further information:None available. Comparisons are regularly made between capillary blood spot and serum 25-hydroxyvitamin D measurements.

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

Email Address For Chasing Results:bcpspathology.info@nhs.net

Methodology:Liquid chromatography tandem mass spectrometry

Site Sample Tested:Sandwell Health Campus

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

Contact Number:0121 507 5385