Testing Service for 25-hydroxy Vitamin D

  • Home test kit for Vitamin D using dried blood spot technology.

  • NHS laboratory - one of the largest providers of Vitamin D testing in the UK.

  • Direct to the public test service since 2011

  • Order online with our eCommerce partner in Birmingham or use our telephone order-line.

  • International orders - We send test packs across the world. Order online using the link below

Online Sales

  • After six years of telephone sales we now have 24 hour secure website ordering. Much more convenient for international orders.

  • Order online here......

  • eCommerce orders are passed to us and we send you the kit.
  • Follow the instructions on how to take the sample and return in envelope supplied
  • Results usually returned within 5 working days from sample receipt. Sent as a pdf attached to an email with a clear interpretation. Example report here.....
  • Please note we can not give refunds for kits that have been sent to you.
  • International orders sent by air mail with results sent by email.


How much does it cost?

  •  £28 to UK and £34 Overseas

  • Bulk Orders : Discount for orders of 10 or more kits of £23 UK and £28 Overseas. Order online here.....

What do we measure?

We use state of the art LC-MS/MS methods to measure Vitamin D in your blood. We report total and D2 and D3 results together with a clear interpretation.


Results are sent to the email address provided on the consent form. If you would prefer, we can post results to you.

Our result form has a clear interpretation of your Vitamin D level. Results are expressed as nmol/L. See our Questions and Answers page for how to convert nmol/L to ng/mL which are the older units still used in the US and some laboratories in the UK.

Continuous Quality Improvement

The process of continuous quality improvement is key to all we do. We welcome feedback on any aspect of our Vitamin D Blood Spot Service. Our laboratory has been accredited by CPA for many years and has recently been assessed by UKAS to the ISO 15189 standards.

You can contact us at: vitd@cityassays.org.uk


Ordering a Test Kit

  • Tel: +44 (0)121 507 4278 Mon-Fri 09.00 - 17.00 UK time. Telephone orders and enquiries/help line

  • 24 hour eShop orders here.....

Video showing how to do the test:

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