define the indications for assessing 1,25-dihydroxyvitamin D (most biologically active form of vitamin D). (vitamindwiki.com)
The main source of the more biologically active 25-hydroxy-Vitamin D3 (25OHVitD3) comes from the action of ultraviolet light on the skin.Aim: To determine if there are differences in concentrations of 25OHVitD3, calcium and PTH in school-aged children throughout. (eurospe.org)
Concentrations9
Measurements of serum concentrations of 25(OH)D were performed as part of the nutrition biomarker component of NHANES III (1988-1994) and in NHANES 2001-2006. (cdc.gov)
1 Serum 25(OH)D concentrations were measured at the National Center for Environmental Health, CDC, Atlanta, GA using the DiaSorin RIA kit (Stillwater MN). (cdc.gov)
Subjects were randomly assigned into two groups by the corresponding author, including intervention (intramuscular injection of 50,000 units of 25(OH) D three days before delivery) and control (with no injection of 25(OH) D). Serum concentrations of 25(OH) D were measured after offspring, including RDS, were collected and recorded in a checklist. (researchsquare.com)
analyze the 2 main methods (immunoassay, liquid chromatography/ tandem mass spectrometry) used for measuring 25-hydroxyvitamin D serum/plasma concentrations and how they may produce different results (including obtaining fractionated vs total 25-hydroxyvitamin D concentrations). (vitamindwiki.com)
If 25-hydroxyvitamin D2 and D3 serum concentrations are separately measured and reported as compared with receiving only a total 25-hydroxyvitamin D concentration, how do the additional fractionated data for vitamin D2 and D3 aid clinical interpretation? (vitamindwiki.com)
What are the methods for measuring 25-hydroxyvitamin D serum concentrations, and how do they differ from one another? (vitamindwiki.com)
The most common laboratory test to assess vitamin D nutritional status is total 25-hydroxyvitamin D serum concentrations. (vitamindwiki.com)
Laboratory professionals are often confronted with challenges related to vitamin D testing, including controversy over optimal and target vitamin D concentrations, variable reference ranges across marketed assays and reference laboratories, lack of standardization of vitamin D assays, and misordering of 1,25-dihydroxyvitamin D testing. (vitamindwiki.com)
Besides analytical problems (hydrophobicity, low circulating concentrations, ability to bind to lipids, albumins and vitamin D binding protein, presence of multiple vitamin D metabolites and variable ratios of 25(OH)D 2 and 25(OH)D 3 in the blood), vitamin D shows great preanalytical variability, since its concentration is drastically influenced by seasonal changes, exposure to sun, type of clothes or sun block creams. (biochemia-medica.com)
Standardization1
This standardization was done so that researchers could use 25(OH)D data that are equivalent to 25(OH)D measurements assayed with a LC-MS/MS method that is traceable to the NIST reference materials. (cdc.gov)
Metabolites2
Ultra high-performance liquid chromatographic (UHPLC) separation of Vitamin D Metabolites― 3-epi-25-hydroxyvitamin D2 and 25-hydroxyvitamin D2, using Supel™ Carbon LC column with baseline separation, excellent peak shape, and sensitivity. (sigmaaldrich.com)
The upgrade to MassChrom® 25-OH-vitamin D3/D2 analysis allows for the separation of the main metabolites of vitamins D3 and D2, 25-Hydroxycholecalciferol and 25-Hydroxyergocalciferol, from their epimeric forms 3-epi-25-OH-vitamin D3 and 3-epi-25-OH-vitamin D2, hence allowing for separate quantification by LC MS/MS. (zskck.com)
Derivatives1
The structure of both the monoacetylated epimers, i.e., 5- O -acetyl-4- C -hydroxymethyl-1,2- O -isopropylidene-α-D-ribo- and xylofuranose obtained by enzymatic acetylation, has been confirmed by an X-ray study on their corresponding 4- C - p -toluenesulfonyloxymethyl derivatives. (beilstein-journals.org)
Compound3
it is the precursor of the physiologically most active compound 1,25-(OH)2-Vitamin D3. (zskck.com)
The synthesis of the ribo - trihydroxy sugar derivative starting from diacetone-D-glucose led to the formation of an inseparable 1:1 mixture of the required compound and its C-3 epimer, i.e., 4- C- hydroxymethyl-1,2- O -isopropylidene-α-D-xylofuranose [10] . (beilstein-journals.org)
Assays2
The aim of this study is to apply accurate assays of vitamin D forms (single hydroxylated (25(OH)D2, 25(OH)D3), double-hydroxylated (1α,25(OH)2D2, 1α,25(OH)2D3), epimers (3-epi-25(OH)D2, 3-epi-25(OH)D3)) in mothers (serum) and neonates (umbilical cord) i) to expl. (endocrine-abstracts.org)
How are 25-hydroxyvitamin D reference ranges (or target values) established, and how do they vary across marketed assays and reference laboratories? (vitamindwiki.com)
Measurement5
As a result, the 25(OH)D measurement has now been standardized using a LC-MS/MS method, which allows laboratories and surveys to compare 25(OH)D measurements. (cdc.gov)
Here, we performed a comparison in samples of healthy donors between the currently routinely used 25(OH)D LC-MS/MS methods in the Netherlands and the Ghent University reference measurement procedure to address this issue (n = 40). (cdc.gov)
In conclusion, five diagnostic centers have performed a comparison with the 25(OH)D Ghent University reference measurement procedure in healthy donor serum samples and a comparison among themselves in patient serum samples. (cdc.gov)
When is measurement of a 1,25-dihydroxyvitamin D serum concentration clinically indicated? (vitamindwiki.com)
If it measurement is clinically relevant and should be considered to classify Vitamin D status is still unknown.Objective: To measure 25OHD3, 25-hydroxy-Vitamin D2 (25OHD2) and Epi25OHD3 and to compare them with PTH and calcemia.Method: Subjects: Children between 5 and 8 years of age born very. (eurospe.org)
Methods4
Concurrent with the recognition of quality control issues for the RIA data from NHANES, an increasing number of publications in the vitamin D field began to describe excessive method bias and imprecision in the methods to measure 25(OH)D available at that time. (cdc.gov)
The variety of LC-MS/MS methods measuring total 25(OH)D used today is vast and the comparability among these methods is still not well assessed. (cdc.gov)
information about the accuracy of routinely used liquid chromatography-tandem mass spectrometry (LC-MS/MS) 25(OH)D methods is very limited. (cdc.gov)
To address this matter, we performed a method comparison study between the currently used routine 25(OH)D LC-MS/MS methods in the Netherlands and the UGhent RPM using healthy donor serum samples and an inter-laboratory method comparison to assess agreement between the different laboratories using routine patient serum samples. (cdc.gov)
Measurements1
The purpose of this analytical note is to inform researchers that serum 25-hydroxyvitamin D (25(OH)D) data from NHANES III (1988-1994) and NHANES 2001-2006 have been converted by using regression to equivalent 25(OH)D measurements from a standardized liquid chromatography-tandem mass spectrometry (LC-MS/MS) method. (cdc.gov)
Vitamin5
What are the clinical implications of misordering 1,25-dihydroxyvitamin D in place of 25-hydroxy-vitamin D? (vitamindwiki.com)
To check vitamin D status, the physician selected a vitamin D panel that includes 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D serum levels. (vitamindwiki.com)
This reagent kit allows for the specific analysis of 25-OH-vitamin D3 and 25-OH-vitamin D2 in serum and plasma by tandem mass spectrometry. (zskck.com)
MassChrom ® Integrated kit for the LC-MS/MS analysis of 25-OH-Vitamin D3 and D2 in serum/plasma, For the automated sample preparation with 96 well filter plates. (zskck.com)
Background: The C3 epimer of 25-hydroxi-vitamin D3 (Epi25OHD3) is present in the pediatric and adult population and varies according to age. (eurospe.org)
Clinical2
This clinical trial aimed to evaluate the consequences of a single-course of antenatal intramuscular injection of 25(OH) D for pregnant women at risk of preterm delivery on the incidence and severity of neonatal respiratory distress syndrome. (researchsquare.com)
The 25-hydroxyvitamin D serum concentration was determined at the medical center central clinical laboratory by enzyme immunoassay, and results were 29 ng/mL (72 nmol/L), which is in the "insufficiency" range according to the reference ranges on the package insert for the assay. (vitamindwiki.com)
Optimal1
25 ng/mL 62 nmol/L defined as "optimal" in the reference range). (vitamindwiki.com)
Laboratory2
To assess the magnitude of changes associated with the reformulated assay, which might impact any observed trends in serum 25(OH)D in the population, the CDC laboratory reanalyzed a subset of banked serum samples from NHANES III using the reformulated version of the RIA. (cdc.gov)
In addition to the DiaSorin assay reformulation, the CDC laboratory observed drifts in the serum 25(OH)D assay performance (as reflected in QC pool shifts in the mean, up or down, by up to 10%) over the period of NHANES 2003-2006. (cdc.gov)
Separately1
The epimers are carried out separately. (synarchive.com)
Structure2
Isolation and structure elucidation of 24-epiclerosterol [24( R )-stigmasta-5, 25-dien-3β-ol], 24( R )-5α-stigmasta-7, 25-dien-3β-ol, 5α-stigmast-24-en-3β-ol and 25-methyl-5α-ergost-24 (28)-en-3β-ol from aerial parts was done 10 . (ijpsr.com)
Compounds that have different structure and same chemical formulas are called as PDF with isomers, carbohydrates, epimers, and isotopes choices for online university classes. (mcqslearn.com)
Analysis1
The LC-MS/MS method was used in the analysis of the newly released NHANES 2007-2010 25(OH)D data. (cdc.gov)
Results1
Several approaches were attempted for harmonizing the 2003-2006 25(OH)D. A model based on RIA quality control pool data was selected because the results should be independent of any empirical trend in the sample participant data. (cdc.gov)
Active form1
Because of relatively poor absorption by the gastrointestinal tract, around 25-75% or even 70-90% of the TCs administrated to animals are excreted in their active form [ 6 ]. (hindawi.com)
Compare1
The LC-MS/MS-equivalent data for NHANES III (1988-1994) and NHANES 2001-2006 are needed to compare with 25(OH)D data from NHANES 2007-2010, which were obtained using the LC-MS/MS method. (cdc.gov)
Data4
It is highly recommended that researchers use the LC-MS/MS-equivalent data for all analyses, but especially to analyze secular trends for 25(OH)D involving 1988-1994, 2001-2006 and 2007-2010 data. (cdc.gov)
As a result, the NHANES 2003-2004 25(OH)D data were generally adjusted to lower values and the 2005-2006 data were generally adjusted to higher values. (cdc.gov)
Use of the LC-MS/MS-equivalent data is strongly recommended for correct interpretation of trends in 25(OH)D data from NHANES III and 2001-2006 when compared with NHANES 2007-2010. (cdc.gov)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). (thcscience.wiki)
Single1
According to this study, a single dose of 50,000 units of intramuscular 25(OH) D in pregnant women at risk of preterm delivery can reduce the incidence of RDS in the newborn. (researchsquare.com)
Study1
The present study aimed to evaluate the effect of 25 - hydroxyvitamin D [25(OH)D] administration in pregnant women at risk of preterm delivery on the incidence of RDS in their preterm neonates. (researchsquare.com)
Control2
The mean 25(OH) D level in neonates was 17.7 ± 10.5 and 23.7 ± 13.5 ng/mL in the intervention and control groups, respectively. (researchsquare.com)
MassCheck® 3- epi -25-OH-D3/D2 and 25-OH- D3/D2 Serum Control, Bi-Level (I + II) (lyoph. (zskck.com)
Week1
the highest incidence being in the 22nd to 24th week of gestation which reduces to 25% at the neonatal weight of 1251 to 1500 grams. (researchsquare.com)
Values1
The variation in 25(OH)D values appeared to be due to method variation that probably resulted from reagent and calibration lot-to-lot variation. (cdc.gov)
Variety1
It is the C-2 epimer of glucose and a component of a variety of polysaccharides in plants. (sdlifesciences.com)