Vitamin D (1, 25 Dihydroxy) Blood Test Marylebone
From 1 October 2026 — until then book at South Kensington or St Paul's. South Kensington · St Paul's
£171
+ £50 phlebotomy fee (per visit)
+ £50 phlebotomy (per visit)
Confidential Results
Secure online portal
Fast Results
5-8 days"
Professional Service
Experienced phlebotomists
Wimpole Street, Marylebone (opening 1 October 2026)
Opening hours from 1 October 2026
- Monday
- 9am – 6pm
- Tuesday
- 9am – 8pm
- Wednesday
- 9am – 6pm
- Thursday
- 9am – 8pm
- Friday
- 8am – 5pm
- Saturday
- 10am – 4pm
- Sunday
- Closed
- Bond Street — about 6 minutes (Central, Jubilee & Elizabeth lines)
- Oxford Circus — about 7 minutes (Central, Bakerloo & Victoria lines)
Wimpole Street, Marylebone
People looking into calcitriol and kidney function in Marylebone are usually looking for the Vitamin D (1, 25 Dihydroxy). It belongs to our vitamin D group and needs a venous blood sample (serum), which a nurse or phlebotomist collects at 22 Wimpole Street, Marylebone once the clinic opens on 1 October 2026. The laboratory typically returns a result in 5-8 days, and the standard price is £171 with no members’ tier.
Vitamin D (1, 25 Dihydroxy)’s place in vitamin D testing
- Sample
- venous blood sample (serum)
- Laboratory turnaround
- 5-8 days
- Appointment
- 20 minutes
- Standard price
- £171 + £50 phlebotomy per visit
Who considers Vitamin D (1, 25 Dihydroxy)
- People often consider this test if they spend most daylight hours indoors or cover their skin for cultural or medical reasons.
- Aching muscles, low mood through the winter months or frequent minor infections are common prompts.
- Those with darker skin living in the UK, or anyone over 65, may want a baseline because synthesis from sunlight is reduced.
- Anyone taking a high-dose supplement sometimes checks that levels have not climbed too far.
- It is frequently added to bone health, fatigue or fertility investigations.
What Vitamin D (1, 25 Dihydroxy) measures
Laboratories file the Vitamin D (1, 25 Dihydroxy) under calcitriol, kidney function and bone health. The following sections set out how a vitamin D test of this kind is measured and read.
The standard vitamin D test measures 25-hydroxyvitamin D, the storage form that most closely reflects what your skin has made and what you have eaten or taken as a supplement over the past few weeks. A less common assay, 1,25-dihydroxyvitamin D, measures the active hormone and is reserved for particular kidney or calcium questions. Neither is a general measure of bone strength on its own.
Preparing for your Vitamin D (1, 25 Dihydroxy)
- 1No fasting or special timing is needed; a sample at any hour of the day is suitable.
- 2Carry on with your usual supplement so the result reflects your actual intake, unless you have been asked to stop it.
- 3Mention recent travel to a sunny climate, because a fortnight of strong sun can lift the reading noticeably.
Sample for this test: venous blood sample (serum).
Understanding your Vitamin D (1, 25 Dihydroxy) results
Results are usually grouped into deficient, insufficient and adequate bands, with a very high band that can indicate excessive supplementation. Because levels swing with the seasons, a late-winter reading tends to be lower than the same person’s late-summer value, so bear the month in mind when you discuss the result with your GP or a clinician. Low results are typically addressed with a supplement plan and a recheck after around three months.
Vitamin D varies with season, skin tone, body weight and supplement use, so an isolated value is a snapshot rather than a verdict on your bone or immune health.
Related areas of testing at Wimpole Street: bone, calcium and parathyroid, nutrition, vitamins and trace elements, wellness and biochemistry profiles, kidney function and electrolytes.
Pricing
Vitamin D (1, 25 Dihydroxy)
Individual test
Phlebotomy Fee
Blood draw by qualified phlebotomist (per visit)
Total
£221Payment is collected at the clinic. The phlebotomy fee is charged once per visit, regardless of the number of tests booked.
From booking the Vitamin D (1, 25 Dihydroxy) to reading your result
- 1
Choose your test
Select the Vitamin D (1, 25 Dihydroxy) and any others you want run from the same visit. Until 1 October 2026 the identical test can be booked at South Kensington or St Paul’s.
- 2
Nurse-led sample
From 1 October 2026 the venous blood sample (serum) is taken at 22 Wimpole Street, Marylebone by our nursing team, led by Precious Agbonmamwen, Registered Adult Nurse (NMC 20H1641E). Identity is checked and any preparation questions answered first.
- 3
UKAS-accredited laboratory
The sample travels to a UKAS-accredited partner laboratory, whose methods and reference ranges match those used across the NHS and private sectors.
- 4
Laboratory report to your secure portal
The laboratory report is released to your secure portal — typically from 24 hours; the laboratory quotes 5-8 days for this test. It shows each value against the reference range and flags anything outside it; discuss the report with your GP or a clinician.
Why test at Wimpole Street
Wimpole Street Medical & Dental opens at 22 Wimpole Street on 1 October 2026. Medical services are for patients aged 16 and over; registration with the CQC is in progress ahead of opening.
Wimpole Street, Marylebone (opening 1 October 2026)
- Bond Street — about 6 minutes (Central, Jubilee & Elizabeth lines)
- Oxford Circus — about 7 minutes (Central, Bakerloo & Victoria lines)
- Repeat or additional tests can usually be added to the same visit rather than requiring a second appointment.
- The same catalogue already runs at South Kensington and St Paul’s, so you can test now and move your records to Marylebone later.
- Bond Street is about six minutes on foot and Oxford Circus about seven, so the clinic suits people working across the West End.
Other tests often considered alongside Vitamin D (1, 25 Dihydroxy)
Frequently Asked Questions
A venous blood sample (serum). A nurse or phlebotomist collects it at 22 Wimpole Street, Marylebone from 1 October 2026; the appointment allows time for identity checks and any preparation questions. The laboratory quotes 5-8 days for this test.
Ready to Book Your Test?
Wimpole Street opens 1 October 2026. Register your interest for the Marylebone diary, or book the same test now at South Kensington or St Paul's.
Important information about the Vitamin D (1, 25 Dihydroxy) at Wimpole Street
- Medical services at Wimpole Street Medical & Dental are for patients aged 16 and over.
- This is a self-referral service: you choose the test and book directly — no GP referral is needed.
- Nurse-led by Precious Agbonmamwen, Registered Adult Nurse (NMC 20H1641E), who oversees sample-taking standards, infection control and the patient pathway. The nursing team does not interpret results.
- A laboratory result is not a diagnosis and this page is not a substitute for medical advice. We do not provide clinical interpretation of results — please discuss your report with your GP or a clinician, particularly if a value is flagged or you have symptoms.
- CQC registration for Wimpole Street is in progress ahead of the opening on 1 October 2026; our South Kensington and St Paul’s clinics are CQC registered.
- Your results are held on a secure portal and treated as strictly confidential, except where disclosure is required by law.
- If you are seriously unwell, call 999. For urgent advice that is not an emergency, call NHS 111.
