Routine Isotope-Dilution Liquid Chromatography–Tandem Mass Spectrometry Assay for Simultaneous Measurement of the 25-Hydroxy Metabolites of Vitamins D2 and D3

Maunsell, Zoë; Wright, D. J.; Rainbow, S

doi:10.1373/clinchem.2005.052936

Cited by 351 publications

(279 citation statements)

References 26 publications

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“…A similar set-up was used for negative controls, except that the reverse transcriptase was omitted and no PCR products were detected under these conditions. Assays Plasma 25OHD levels were analyzed by isotope dilution liquid chromatography-tandem mass spectrometry (LC-MS/MS), using a method adapted from Maunsell et al 46 The method quantifies 25OHD 2 and 25OHD 3 , including the 3-epimer form, which is not separated from 25OHD 3 . Calibrators traceable to NIST SRM 972 (Chromsystems, GmbH, Munich, Germany) were used.…”

Section: Real-time Reverse Transcriptase-pcr For Mrna Analysismentioning

confidence: 99%

Expression of vitamin D-metabolizing enzymes in human adipose tissue—the effect of obesity and diet-induced weight loss

et al. 2012

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OBJECTIVE: Low vitamin D (VD) levels are common in obesity. We hypothesized that this may be due to metabolism of VD in adipose tissue (AT). Thus, we studied (1) whether the VD-metabolizing enzymes were expressed differently in AT of lean and obese individuals and in visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT), and (2) whether their expression was influenced by weight loss. METHODS: Samples of SAT and VAT were analyzed for expression of the vitamin-D-25-hydroxylases CYP2R1, CYP2J2, CYP27A1 and CYP3A4, the 25-vitamin-D-1a-hydroxylase CYP27B1, the catabolic vitamin-D-24-hydroxylase CYP24A1, and the vitamin D receptor, using reverse transcriptase-PCR. Moreover, plasma 25-hydroxy-vitamin D (25OHD) level was measured and related to the expression of these enzymes. Samples of SAT and VAT from 20 lean women and 20 obese women, and samples of SAT from 17 obese subjects before and after a 10% weight loss were analyzed. RESULTS: A plasma 25OHD level o50 nmol l À 1 was highly prevalent in both lean (45%) and obese (90%) women (Po0.01). Plasma 25OHD increased by 27% after weight loss in the obese individuals (Po0.05). Expression levels of the 25-hydroxylase CYP2J2 and the 1a-hydroxylase CYP27B1 were decreased by 71% (Po0.0001) and 49% (Po0.05), respectively, in SAT of the obese. CYP24A1 did not differ between lean and obese women, but the expression was increased by 79% (Po0.05) after weight loss. CONCLUSION: Obesity is characterized by a decreased expression of the 25-hydroxylase CYP2J2 and the 1a-hydroxylase CYP27B1 in SAT, whereas the catabolic CYP24A1 does not differ between lean and obese women. However, the expression of CYP24A1 is increased after weight loss. Accordingly, AT has the capacity to metabolize VD locally, and this can be dynamically altered during obesity and weight loss. INTRODUCTIONLow levels of circulating 25-hydroxy-vitamin D (25OHD) are associated with increased fat mass and body mass index, 1-5 but the underlying mechanism for this association is not fully elucidated. 6 Vitamin D (VD) is stored in adipose tissue (AT), and release of VD from AT is proposed to serve as an endogenous source of VD during the winter, when cutaneous production is low or absent in several parts of the world. 7 As low circulating levels of 25OHD are common in association with the obese state, 8 several studies have examined the effect of weight loss on circulating levels of 25OHD. However, results are inconsistent. After diet-and exercise-induced weight loss, both increased 9-11 and unaltered 12,13 circulating levels of 25OHD have been reported. Likewise, after major weight loss by bariatric surgery, both temporary 14-16 and long-term increases [16][17][18] in circulating levels of 25OHD have been reported, along with reports of no changes one year after surgery. 13,19 Taken together, these findings indicate that body weight is an important factor for circulating 25OHD levels. Several other explanations for the low levels of 25OHD in obesity have been proposed: a decreased exposure to sun light, 20 ...

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Section: Real-time Reverse Transcriptase-pcr For Mrna Analysismentioning

confidence: 99%

Expression of vitamin D-metabolizing enzymes in human adipose tissue—the effect of obesity and diet-induced weight loss

et al. 2012

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“…We analyzed plasma 25OHD levels by isotope dilution liquid chromatography-tandem mass spectrometry according to a method adapted from Maunsell et al 32 and described earlier in detail. 33 The method quantifies both 25OHD 2 and 25OHD 3 .…”

Section: Biochemistrymentioning

confidence: 99%

Maternal and infant vitamin D status during the first 9 months of infant life—a cohort study

et al. 2013

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BACKGROUND/OBJECTIVES: The objective of this study was to assess vitamin D status and possible consequences of low plasma 25-hydroxyvitamin D (25OHD) levels in a population of healthy mothers and their infants. SUBJECTS/METHODS: A total of 107 women aged 24-41 years gave birth to 108 infants. They were followed up three times during 9 months. RESULTS: Cord blood 25OHD level (43.3 ± 20.4 nmol/l) on average was 62 ± 16% of maternal levels (73.3 ± 30.7 nmol/l), measured 1-2 weeks postpartum. Cord blood 25OHD correlated positively with maternal 25OHD levels (r ¼ 0.83, Po0.001). At birth, 23% of mothers and 61% of infants had 25OHD o50 nmol/l. Vitamin D deficiency (25OHDo25 nmol/l) was present in 66% of the children born by mothers with 25OHD levels below 50 nmol/l (Po0.01), whereas only one child was born with deficiency among mothers with 25OHD 450 nmol/l. During follow-up, most of the children (485%) had 25OHD levels 450 nmol/l, which most likely was attributable to the use of supplements, as more than 95% of the children were given daily vitamin D supplements of 10 mg of vitamin D. Cord blood parathyroid hormone levels were very low (median 0.21; interquartile range 0.11-0.33 pmol/l), with increasing levels (Po0.01) reaching 3.08 (2.67-3.92 pmol/l) at the last visit. Vitamin D levels were not associated with anthropometric indices of the newborn infant or their growth during follow-up. CONCLUSIONS: Vitamin D deficiency is widespread in newborn. Maternal 25OHD levels above 50 nmol/l are needed to prevent vitamin D deficiency among newborn.

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“…Two phospholipids (lyso-phosphotidylcholine C16:0 and C18:0) were monitored for potential coelution. Since 1aOHD3 has the same molecular weight as 25OHD3 and was noted in a previous publication (28) as a possible interferent, we performed testing by injecting an ethanolic solution containing both 1aOHD3 and 25OHD3.…”

Section: Validation Methodsmentioning

confidence: 99%

“…Attention should be given to the late elution peaks which might interfere with the analysis of succeeding samples (25). Although LC-MSMS is considered the most accurate technology for 25OHD quantification (17,27), 1a-hydroxyvitamin D 3 (1aOHD3) (28) and the C3 epimer of 25OHD (3-epi 25OHD) (29) could be significant interferents due to the same molecular weight if not separated by LC. Most LC-MSMS methods employ deuterated 25OHD3 as internal standard.…”

Section: Introductionmentioning

confidence: 99%

“…For direct measurement, sample preparation could be cumbersome. In general, sample preparation includes protein precipitation followed by solid-phase extraction (32)(33)(34) or liquid-liquid extraction (28,35,36). Turbulent flow technology is a robust and rapid online purification tool for high efficiency extraction (37,38), and has been used for online sample cleaning for serum 25OHD quantification (29).…”

Section: Introductionmentioning

confidence: 99%

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Development and validation of a liquid chromatography-tandem mass spectrometry assay for serum 25-hydroxyvitamin D2/D3 using a turbulent flow online extraction technology

Bunch

Miller

Wang

2009

Clinical Chemistry and Laboratory Medicine

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Background: Vitamin D is important to health and disease. Liquid chromatography-tandem mass spectrometry (LC-MSMS) is considered the most accurate technology for quantification of serum 25-hydroxyvitamin D (25OHD) which is the best biomarker for estimating vitamin D nutritional status. Methods: Serum was mixed with acetonitrile containing hexadeuterated 25-hydroxyvitamin D 3 (d 6 -25OHD3) and centrifuged 10 min at 15,634=g. The supernatant was injected onto a turbulent flow preparatory column then transferred to a polar endcapped C18 analytical column. The mass spectrometer was set for positive atmospheric pressure chemical ionization. Results:The analytical cycle time was 5.5 min. Interand intra-assay CV for both analytes across three concentrations ranged from 3.8% to 14.2%. The method was linear from 3.0 to 283.6 nmol/L for 25-hydroxyvitamin D 3 (25OHD3) and 4.6 to 277.9 nmol/L for 25-hydroxyvitamin D 2 (25OHD2), with an accuracy of 88.7%-118.7% and 90.7%-100.3%, respectively. No carryover or ion suppression was observed. Comparison with a radioimmunoassay using patient specimens (ns527) showed a mean difference of 5.

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Routine Isotope-Dilution Liquid Chromatography–Tandem Mass Spectrometry Assay for Simultaneous Measurement of the 25-Hydroxy Metabolites of Vitamins D2 and D3

Cited by 351 publications

References 26 publications

Expression of vitamin D-metabolizing enzymes in human adipose tissue—the effect of obesity and diet-induced weight loss

Expression of vitamin D-metabolizing enzymes in human adipose tissue—the effect of obesity and diet-induced weight loss

Maternal and infant vitamin D status during the first 9 months of infant life—a cohort study

Development and validation of a liquid chromatography-tandem mass spectrometry assay for serum 25-hydroxyvitamin D2/D3 using a turbulent flow online extraction technology

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