Description
General description
Determining total 25-hydroxy vitamin D [25(OH)D] concentration in serum, the sum of 25-hydroxyvitamin D₂ [25(OH)D₂] and 25-hydroxyvitamin D₃ [25(OH)D₃] is generally considered a reliable indicator of vitamin D status. Measurement of 24R, 25(OH)₂D₃ in serum is considered a catabolism marker and an indicator of kidney disease. A unit of SRM 972a contains 1 mL of four vials (levels 1 through 4) of frozen serum with different concentration levels of 25-hydroxyvitamin D [25(OH)D] and 24R, 25-dihydroxy vitamin D₃ [24R,25(OH)₂D₃].
NIST972A_Cert
NIST972A_SDS
Application
This vitamin D metabolite standard reference material (SRM) is intended for use as an accuracy control in the evaluation of methods for determining the amount-of-substance concentration of vitamin D metabolites in human serum. This SRM can also be used as a quality assurance tool for assigning values to in-house control materials for these constituents.
Vitamin D metabolites in frozen human serum has been used as a reference material for the calibration and standardization of 25-hydroxyvitamin D (25(OH)D) from dried blood spot samples by liquid chromatography-tandem mass spectrometry (LC-MS/MS).
Biochem/physiol Actions
Vitamin D known as cholecalciferol exists as vitamin D₃. It is taken in the diet through fortified dairy products and fish oils. It is synthesized in the skin from 7-dehydrocholesterol by ultraviolet irradiation. The biologically active form of vitamin D, 25(OH)₂D₃, is essential for mineral metabolism, and for other physiological functions like inhibition of growth of cancer cells and protection against certain immune mediated disorders.
Preparation Note
The vials should be stored in the dark at a temperature between –20 °C and –80 °C.
Before use, the vial/s must be thawed at room temperature for about 30 mins in subdued light.
Other Notes
Information on expiry, storage, and usage is provided in the NIST certificate.
Notes on Biomaterials, disposal, and transport are available on NIST MSDS.
Legal Information
NIST is a registered trademark of National Institute of Standards and Technology
SRM is a registered trademark of National Institute of Standards and Technology
