General Description

A Certified Spiking Solution? of 25-Hydroxyvitamin D3, a prohormone whose blood serum levels are used to determine Vitamin D nutritional status. This solution standard is suitable for critical quantitative applications in research and clinical environments including: for use in preparation of controls and calibrators for LC/UV and LC-MS/MS assays; as system tuning/suitability standards; linearity verification; internal proficiency testing; and for OEM use in preparation of reagents, development of assays and instrument IQ/OQ. The stable, quantitative solution format provides significant benefits to the user including material savings, increased efficiency of labor, and convenience of use. The shelf stable Snap-N-Spike? format allows laboratories to eliminate painstaking weighing operations and provides the ability to spike a known concentration of analyte into their matrix of choice just before use.

Biochem/physiol Actions

Cholecalciferol is an inactive form of vitamin D3 which undergoes various levels of hydroxylation to form active vitamin D3 analogs. 1α-Hydroxyvitamin D3 (alfacalcidol) is a synthetic analog that is metabolized to 1,25-dihydroxycholecalciferol, the biologically active form of vitamin D3. Other analogues of cholecalciferol result from different hydroxylations. 25-dihydroxycholecalciferol is a the major circulating form of vitamin D3 and a physiological precursor of 1α,25-Dihydroxycholecalciferol. The conversion is catalyzed by 25-Hydroxyvitamin D3 1-α-hydroxylase (VD3 1A hydroxylase) also known ascytochrome p450 27B1 (CYP27B1).