Test Database

Description

A Gerstel Multi Purpose Sampler coupled with liquid chromatography and electrospray ionisation tandem mass spectrometry (LC-ESI-MS/MS) for the determination of 25 OH vitamin D2 and D3 Due to the relocation of the Nutristasis service to the Blackfriars Hub site, this test is not currently accredited by UKAS to ISO15189.

Clinical details

Vitamin D is converted into 25-OH vitamin D in the liver. This is the major storage form of vitamin D and is the analyte of choice for determination of the vitamin D status. Hypocalcaemia can result from vitamin D deficiency or disorders of vitamin D metabolism such as renal failure. Hyper and hypo-phosphataemia can each be caused by vitamin D excess and deficiency respectively. Vitamin D deficiency prevents normal absorption of calcium from the gut leading to increased mobilisation of calcium from the bone in order to maintain blood concentrations. The resulting demineralisation of bone leads to bone weakness known as rickets in children, or osteomalacia in adults. Vitamin D deficiency can occur secondary to various diseases that cause fat malabsorption. These include cystic fibrosis, primary biliary cirrhosis, short bowel syndrome, pancreatic disease and Crohn's disease. Vitamin D toxicity is due to over-consumption of supplements and cannot be caused by excess exposure to sunlight.

Related condition

vitamin D deficiency, osteomalacia, rickets, hypocalcemia

Reference range

<25 nmol/L     – vitamin D deficiency

25-50 nmol/L  – vitamin D insufficiency

>50 nmol/L    – good vitamin D status

Units

nmol/L

Synonyms

cholecalciferol, ergocalciferol, vitamin D2 and D3

Testing site

Synnovis : Reference Services : Blackfriars Hub

Laboratory

Nutristasis Unit