Test Background 25-hydroxy vitamin D3 is the storage form of vitamin D3 from which 1,25-dihydroxy vitamin D3 is synthesised. 1,25-dihydroxy vitamin D acts as a hormone and stimulates intestinal calcium/phosphate absorption and increased bone resorption.
Clinical Indications Investigation of vitamin D deficiency 25-hydroxy vitamin D3 and 25-hydroxy vitamin D2 concentrations to assess treatment efficacy in established vitamin D deficiency Differential diagnosis of bone disease Investigations of hyperparathyroidism secondary to chronic kidney disease
Reference Range Replete: 70-150 nmol/L Insufficient: 40-70 nmol/L Deficient: <40 nmol/L
Sample Required Serum (red top)
Sample Volume 0.5 mL
For referred samples:
Stable at 2-8oC for 72 hours. Please freeze pending dispatch for analysis.
Sample can be sent by first class post.
Turnaround Time 1 week
Grossly haemolysed samples are unsuitable for this assay.