scholarly journals The variation in free 25-hydroxy vitamin D and vitamin D-binding protein with season and vitamin D status

2017 ◽  
Vol 6 (2) ◽  
pp. 111-120 ◽  
Author(s):  
Göran Oleröd ◽  
Lillemor Mattsson Hultén ◽  
Ola Hammarsten ◽  
Eva Klingberg

Purpose Serum 25-hydroxy vitamin D [25(OH)D] varies greatly with season at northern latitudes. The purpose of this study was to determine if the seasonal variations in serum total 25(OH)D are followed by a concomitant variation in free 25(OH)D or if the variation is damped by alterations in the binding capacity of DBP. Methods Serum was collected from 540 healthy blood donors (60% men; mean age 41 ± 13 years) during 12 months and analyzed for total 25(OH)D, directly measured free 25(OH)D, vitamin D-binding protein (DBP) and albumin. Calculated free 25(OH)D was estimated. Results The UV-B radiation during the sampling month was positively correlated with the serum levels of total 25(OH)D (r = 0.355, P < 0.001), directly measured free (r = 0.336, P < 0.001) and calculated free 25(OH)D (r = 0.275, P < 0.001), but not with DBP and albumin. The percentage of free 25(OH)D was higher during the winter months than that during the summer months (0.020 ± 0.005% vs 0.019 ± 0.004%; P = 0.007) and higher in participants with a serum 25(OH)D below 25 nmol/L than that in participants with a serum 25(OH)D above 75 nmol/L (0.031 ± 0.007% vs 0.017 ± 0.003%; P < 0.001). iPTH was correlated with directly measured free 25(OH)D (r = −0.226; P < 0.001), but only weakly with calculated free 25(OH)D (r = −0.095; P = 0.027). Conclusions Directly measured free serum 25(OH)D was highly correlated with total serum 25(OH)D and followed the same seasonal variation, whereas the serum concentrations of DBP and albumin were stable. The fluctuation in free 25(OH)D was only marginally damped with an increase in the percentage of free 25(OH)D during the winter months and in participants with vitamin D deficiency.

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Elif Börekci ◽  
Mahmut Kılıç ◽  
Zeynep Ozan ◽  
Hasan Börekci ◽  
Tekin Yıldırım ◽  
...  

Abstract Objectives There is no reliable and valid biomarker to identify Irritable bowel syndrome (IBS) and its subtypes. The aim of this study is to explore potential serum biomarkers that may be associated with IBS subtypes, particularly in the vitamin D pathway. Methods The study population comprised 75 IBS patients and 79 controls. Patients divided into IBS subtypes. Routine biochemical parameters, 25-OH-vitamin D, vitamin D binding protein (VDBP) and vitamin D receptor (VDR) serum levels were compared between IBS subtypes and controls. Factors related to IBS subtypes were examined by multivariate logistic regression analysis. Results Vitamin D levels were lower; VDBP and VDR were higher in all IBS patients than in controls (p<0.001; 0.047 and 0.029, respectively). According to logistic regression analysis, VDBP was a disease-related parameter as much as vitamin D in all IBS subtypes. C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) were higher especially in diarrhea-dominant IBS (IBS-D) (p=0.041; 0.046) and vitamin B12 were significantly lower in constipation-dominant IBS (IBS-C) (p=0.001). Conclusions Increased VDBP levels were associated with all IBS subtypes. Patients, especially in IBS-D, had higher serum levels of VDBP, CRP and ESR. Vitamin B12 deficiency, which we consider as a result of the disease, was more common in IBS-C.


BMC Neurology ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Zhila Maghbooli ◽  
Abolfazl Omidifar ◽  
Tarlan Varzandi ◽  
Tayebeh Salehnezhad ◽  
Mohammad Ali Sahraian

Abstract Background In this study, we aimed to determine the risk association between vitamin D binding protein (VDBP) polymorphism in patients with multiple sclerosis (MS) in a MS biobank and the difference in VDBP serum levels in MS patients who were recently diagnosed. Method The current case-control study was performed on 296 MS patients and 313 controls. Thereafter, two common missense VDBP polymorphisms, named rs7041and rs4588, were evaluated in all the participants. Serum levels of vitamin D and vitamin D binding protein were assessed in 77 MS patients who were diagnosed since one year ago and in 67 healthy people who were matched in terms of age and sex. Result The frequency distributions of VDBP genotypes and alleles of SNP rs7041 and rs4588 were observed to be similar in both the MS and control groups (p > 0.05). The VDBP haplotypes, as Gc2/Gc2, Gc1/Gc1, and Gc1/Gc2, were found to be similar in the MS and control groups (p > 0.05). In subgroup analysis, circulating VDBP was lower in MS patients (Ln-VDBP (μgr/ml): 3.64 ± 0.91 vs. 5.31 ± 0.77, p = 0.0001) even after adjusting for vitamin D levels, body mass index, and taking vitamin D supplement. There was no significant association between VDBP haplotypes and vitamin D levels in the two groups. Conclusion The present study suggested an association between lower levels of circulating VDBP and multiple sclerosis in newly diagnosed patients. However, the VDBP causative role in the development of MS is still unclear, so it needs more studies.


2014 ◽  
Vol 68 (10) ◽  
pp. 1272-1277 ◽  
Author(s):  
A. Celikbilek ◽  
A. Y. Gocmen ◽  
G. Zararsiz ◽  
N. Tanik ◽  
H. Ak ◽  
...  

2014 ◽  
Vol 2014 ◽  
pp. 1-12
Author(s):  
James Freeman ◽  
Kimberly Wilson ◽  
Ryan Spears ◽  
Victoria Shalhoub ◽  
Paul Sibley

Vitamin D status in different populations relies on accurate measurement of total serum 25-hydroxyvitamin D [25(OH)D] concentrations [i.e., 25(OH)D3and 25(OH)D2]. This study evaluated agreement between the ADVIA Centaur Vitamin D Total assay for 25(OH)D testing (traceable to the NIST-Ghent reference method procedure) and a liquid chromatography tandem mass spectrometry (LC-MS/MS) method for various populations with different levels of vitamin D binding protein (DBP). Total serum 25(OH)D concentrations were measured for 36 pregnant women, 40 hemodialysis patients, and 30 samples (DBP-spiked or not) from healthy subjects. ELISA measured DBP levels. The mean serum DBP concentrations were higher for pregnancy (415 μg/mL) and lower for hemodialysis subjects (198 μg/mL) than for healthy subjects and were highest for spiked serum (545 μg/mL). The average bias between the ADVIA Centaur assay and the LC-MS/MS method was −1.4% (healthy), −6.1% (pregnancy), and 4.4% (hemodialysis). The slightly greater bias for samples from some pregnancy and hemodialysis subjects with serum DBP levels outside of the normal healthy range fell within a clinically acceptable range—reflected by analysis of their low-range (≤136 μg/mL), medium-range (137–559 μg/mL), and high-range (≥560 μg/mL) DBP groups. Thus, the ADVIA Centaur Vitamin D Total assay demonstrates acceptable performance compared with an LC-MS/MS method for populations containing different amounts of DBP.


Diagnostics ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 278
Author(s):  
Alina Grama ◽  
Lucia Burac ◽  
Cornel Olimpiu Aldea ◽  
Bogdan Bulata ◽  
Dan Delean ◽  
...  

This study aimed to analyse vitamin D-binding protein (Gc-globulin) serum levels in acute liver failure (ALF) in children in relation to disease outcomes and correlations with other known markers used to evaluate the severity of ALF. Our study included 34 children (mean age 4.87 ± 5.30 years) with ALF of different causes (metabolic, 26.47%; autoimmune, 23.53%; toxic, 20.59%; infection, 17.65%; unknown, 11.76%) and 30 children without any liver injury (mean age 6.11 ± 4.26 years). The outcome was poor in 14 patients (41.18%), including one child with liver transplantation (2.94%). Serum Gc-globulin levels were significantly lower in ALF patients compared to the control group (151.57 ± 171.8 mg/L vs. 498.63 ± 252.50 mg/L; p < 0.000001), with an optimum cut-off of 163.5 mg/L (Area Under the Curve, AUC, 0.8921; sensitivity, 76.50%; specificity, 100%). Levels were also lower in patients with poor outcomes compared to survivors (59.34 ± 33.73 mg/L vs. 216.12 ± 199.69 mg/L; p < 0.0001), with an optimum cut-off 115 mg/L (AUC, 0.7642; sensitivity, 100%; specificity, 50%). Gc-globulin serum levels were variable according to ALF aetiology, i.e., lower in metabolic, infectious, or unknown causes compared to autoimmune and toxic causes. Gc-globulin serum levels were decreased in children with ALF and lower in those with poor outcomes compared with survivors. Gc-globulin serum levels were correlated with other known parameters used to evaluate the severity of ALF and could help to identify patients at high risk for poor outcomes.


1990 ◽  
Vol 122 (6) ◽  
pp. 715-721 ◽  
Author(s):  
Dorthe Hartwell ◽  
Christian Hassager ◽  
Kirsten Overgaard ◽  
Bente Juel Riis ◽  
Jan Pødenphant ◽  
...  

Abstract. We assessed the effects of a continuous oral combination of estradiol and norethisterone acetate, nandrolone decanoate, or salmon calcitonin on the vitamin D endocrine system. One hundred and nineteen postmenopausal women, aged 55-75 years, with at least one osteoporotic fracture, were randomly allocated to one year of treatment with estradiol and norethisterone acetate, nandrolone decanoate, or calcitonin, all drugs with a beneficial effect on bone. All three trials were double-blind and placebo-controlled; 104 women (87%) completed the study. We measured the total serum concentration of 1,25-dihydroxyvitamin D (1,25(OH)2D) and vitamin D-binding protein, and estimated the free 1,25(OH)2D index and the "24-hydroxylase activity" initially, and at 6 and 12 months. Furthermore, the 24-h urinary excretions of calcium, phosphate, and adenosine 3'-5'-cyclic monophosphate were assessed initially and at 12 months. The serum concentration of vitamin D-binding protein and 1,25(OH)2D increased transiently during estradiol and norethisterone acetate treatment and vitamin D-binding protein decreased transiently during nandrolone decanoate treatment. None of the other parameters were significantly affected by any of the three treatments. The risk of type II errors was below 10 per cent for all vitamin D measurements. We conclude that the vitamin D metabolites are unlikely to be of major importance for the mechanism by which these drugs exert their positive skeletal effects.


2011 ◽  
Vol 38 (10) ◽  
pp. 2224-2229 ◽  
Author(s):  
KYONG-HEE JUNG ◽  
TAE-HWAN KIM ◽  
DONG-HYUK SHEEN ◽  
MI-KYOUNG LIM ◽  
SANG-KWANG LEE ◽  
...  

Objective.Genetic factors account for more than 90% of overall susceptibility to ankylosing spondylitis (AS), and recent studies have focused on non-major histocompatibility complex genes. Vitamin D binding protein (DBP) is a highly polymorphic protein that transports vitamin D and its metabolites. In addition to its sterol binding capacity, DBP has many other roles in the inflammatory and immune systems, and has been reported to be associated with autoimmune diseases. We investigated the association between DBP polymorphisms and susceptibility to AS.Methods.This case-control study was conducted in 223 patients with AS and 239 ethnically matched controls who were genotyped for 8 single-nucleotide polymorphisms (SNP) in the DBP and its promoter. Genomic DNA was isolated from peripheral blood leukocytes using the standard phenolchloroform method, and the GoldenGate assay was used for genotyping.Results.No significant association was found between the susceptibility to AS and DBP polymorphisms. In a subgroup analysis of patients with AS, G alleles at rs222016 and rs222020 (OR 0.63, 95% CI 0.42–0.95, p = 0.03; OR 0.63, 95% CI 0.42–0.95, p = 0.03, respectively) and A allele at rs3733359 (OR 0.59, 95% CI 0.39–0.90, p = 0.01) showed the decreased risk of peripheral arthritis. G allele at rs4752 showed increased risk of uveitis (OR 2.04, 95% CI 1.12–3.72, p = 0.02). On the haplotype analyses, haplotype 2 (AGGA) protected against the development of peripheral arthritis (p = 0.01) and haplotype 3 (GAAG) was associated with an increased likelihood of uveitis (p = 0.02).Conclusion.DBP gene polymorphisms are associated with the development of peripheral arthritis and uveitis in Korean patients with AS. Given the influence of different DBP variants on the immune system, larger-scale studies are warranted to elucidate the role of DBP in the pathogenesis of AS.


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