Vitamin D

Test Alias / Common Abbreviations

Vitamin D (total)

Department

 

Biochemistry
Royal Stoke University Hospital, County Hospital, Leighton Hospital, Macclesfield District General Hospital 


Pre-analytical information  

 

Add-on requests: accepted up to 48 hours post sampling

Minimum Retest Interval: 6 months (180 days)

 

Sample  Collection instructions:

 

Collect the blood sample using normal venepuncture technique into a serum gel/plain serum tube (gold/red-top).

 

Sample Transport & Stability Information:

 

Samples should be sent to the laboratory on the same day as collection to ensure sample integrity is maintained.  If a delay in receipt of the sample is anticipated, please contact the laboratory to discuss storage requirements.

Stable in separated serum for 24 hours at room temperature and 7 days at 4-8oC.

For generic information on test requesting, sample labelling and packaging, and sample transport – see the frequently asked questions here.

 

Sample Type, Container & Volume

Adult sample type:

 

 

 

 

 

 

 

 

 

 

 

 

 

Paediatric sample type:

Plain serum

 

Turnaround Time

Based on receipt at testing site.

Within 24 hours.

 

 

 

 

 

Age

Vitamin D

Reference Range (nmol/L)

All

50.1 - 200.0

<25 nmol/L:     Deficiency
25-50 nmol/L:    Insufficiency
>50 nmol/L:    Normal

For more guidance on vitamin D requesting and interpretation in adults please see NICE Clinical Knowledge Summary (“Vitamin D deficiency in adults”).

For users in the Staffordshire and Stoke-on-Trent region, local guidance can be found at: Staffordshire and Stoke on Trent Vitamin D guidelines v1.0 October 2024.pdf

Results outside the reference range do not necessarily indicate disease. Similarly, results within the reference range do not preclude abnormality. Please contact the Duty Biochemist for discussion of individual patient results.

Investigation of vitamin D deficiency/toxicity in selected patients. See NICE CKS for more details.

For users in the Staffordshire and Stoke-on-Trent region, local guidance can be found at: Staffordshire and Stoke on Trent Vitamin D guidelines v1.0 October 2024.pdf

In most cases, re-testing after treatment of vitamin D deficiency is not required.

Indications for testing:

  • Suspected osteomalacia
  • Chronic widespread pain with other features of osteomalacia (such as proximal muscle weakness)
  • Known bone disease, where correction of vitamin D deficiency is needed prior to specific treatment

Do NOT test:

  • Asymptomatic people at higher risk of vitamin D deficiency
  • Symptoms of tiredness alone

There are a number of non-pathological factors that can influence levels of specific analytes, giving falsely elevated or reduced levels. If you require more information regarding the effects of these factors on the individual test results, please contact the Duty Biochemist.

Serum/plasma samples are routinely screened for the presence of haemolysis, icterus and lipaemia. Results are not reported if one or more of these has been detected at levels deemed to have had a significant impact on the accuracy of the test.

For more information, please see the following: https://labtestsonline.org.uk/tests/vitamin-d

Reviewed / Updated On: 02/12/2025