Version 2.77


24,25-dihydroxyvitamin D (24,25 DHD), also known as 24r-Hydroxycalcidiol, is an INactive metabolite produced by alternative hydroxylation of 25 hydroxyvitamin D (25HDN) by the CYP24A1 enzyme. The hydroxylation by CYP24A1 competes with hydroxylation to active form 1,25-dihydroxyvitamin D (1,25 DHD) by the CYP27B1 enzyme, and is an important process that prevents overproduction of 1,25 DHD and resulting vitamin D toxicity. Testing for an elevated ratio of 25HDN to 24,25 DHD can be used to reveal the likely presence of mutations in the CYP24A1 gene PMID: 22648296. Source: Regenstrief LOINC

Basic Part Properties

Part Display Name
25-Hydroxyvitamin D3+25-Hydroxyvitamin D2/24,25-dihydroxyvitamin D3+24,25-dihydroxyvitamin D2 ratio panel
Part Type
Component (Describes the core component or analyte measured)
Created On
Construct for LOINC Short Name
25D3+25D2/24,25D3+24,25D2 Pnl

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