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