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COVID-19 (Coronavirus info)

Information and guidance for public, NHSGGC staff, and community-based services.  Hospital visiting restrictions now in place.

1,25 - dihydroxy Vitamin D

1,25-dihydroxy vitamin D (1,25DHD) is the active form of vitamin D, produced primarily by the kidney by hydroxylation of 25-hydroxy vitamin D. 1,25DHD is the form of vitamin D that stimulates resorption of calcium from bone, intestinal absorption and renal reabsorption.

NB. 1,25DHD should not be used to determine vitamin D status; 25-hydroxy vitamin D is the best marker for this purpose.

Indications for 1,25DHD are limited. Measurement may be useful in the investigation of possible vitamin D-dependent rickets and in patients with hypercalcaemia to investigate possible excess 1,25DHD production e.g. granulomatous diseases (sarcoidosis, TB or lymphoma). 

Sample Requirements and Reference Ranges

Sample type  Serum
Container  SST
Precautions  None
Minimum volume 250 ul
Reference range  20 - 120 pmol/L (interim range pending further evaluation)
Turnaround time  35 days
Method  IDS iSYS                                                          
Quality Assurance
Last Updated: 01 April 2021