Clinical Usefulness of Bioavailable Vitamin D and Impact of <i>GC</i> Genotyping on the Determination of Bioavailable Vitamin D in a Korean Population

Kim, Sujeong; Kim, Jin Hyun; Jung, Myeong Hee; Cho, In Ae; Kim, Young‐Jin; Cho, Min-Chul

doi:10.1155/2019/9120467

Cited by 12 publications

(18 citation statements)

References 34 publications

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“…VMR was calculated by dividing serum 24,25(OH) 2 D concentration by serum 25(OH)D concentration and then multiplying by 100 [ 25 ]. Based on total 25(OH)D, VDBP, and albumin concentrations, bioavailable 25(OH)D concentration was calculated using the equations from previous studies [ 20 , 29 ]. According to our previous research [ 20 ], genotype-independent VDBP binding affinity (0.7 × 10 9 M −1 ) was used for calculation of bioavailable 25(OH)D concentration.…”

Section: Methodsmentioning

confidence: 99%

“…It has been reported that the affinity of VDBP for 25(OH)D depends on the polymorphic isoform, therefore, the GC genotype may also play a role in determining the concentration of bioavailable 25(OH)D [ 16 , 17 , 19 ]. However, in our previous study, we found that the GC genotype did not significantly affect the concentration of bioavailable 25(OH)D in the Korean population [ 20 ].…”

Section: Introductionmentioning

confidence: 95%

“…It has been reported that vitamin D-related metabolism varies according to race, and research has been conducted to assess the potential of bioavailable 25(OH)D and 25(OH)D as biomarkers of vitamin D status in general Korean population [ 20 , 26 ]. However, research related to 24,25(OH) 2 D and VMR has not yet been conducted in Asians, including Koreans.…”

Section: Introductionmentioning

confidence: 99%

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Serum 24,25-dihydroxyvitamin D level in general Korean population and its relationship with other vitamin D biomarkers

et al. 2021

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Background Vitamin D status is presently assessed by measuring total serum concentration of 25-hydroxyvitamin D [25(OH)D]. However, 25(OH)D concentration alone might not accurately reflect vitamin D status owing to its weak relationship with various clinical indices and inconsistency across races. Recently, 24,25-dihydroxyvitamin D [24,25(OH)2D] and vitamin D metabolite ratio [VMR; ratio of 24,25(OH)2D to 25(OH)D] have emerged as vitamin D biomarkers. The present study aimed to determine the values of 24,25(OH)2D and VMR in healthy Koreans and compare them with other vitamin D biomarkers, including 25(OH)D and bioavailable 25(OH)D. Methods Serum samples and medical information were collected from 200 individuals (100 females and 100 males) who underwent general health checks without self-reported symptoms. We measured 24,25(OH)2D concentration using liquid chromatography–tandem mass spectrometry, and concentrations of 25(OH)D and vitamin D binding protein using immunoassays. VMR and bioavailable 25(OH)D concentration were calculated using the above data. Serum parathyroid hormone level, and bone mineral density (BMD) data were collected as clinical outcomes, and the effects of the vitamin D markers on them were tested using multiple linear regression models. Results The mean values of 25(OH)D, 24,25(OH)2D, VMR, and bioavailable 25(OH)D were 24.3 ± 8.5 ng/mL, 1.9 ± 1.1 ng/mL, 7.6 ± 2.5, and 3.2 ± 1.2 ng/mL, respectively. The concentration of 25(OH)D closely correlated with 24,25(OH)2D (R = 0.868, P < 0.001) and bioavailable 25(OH)D (R = 0.862, P < 0.001). No significant effects of 24,25(OH)2D, VMR, and bioavailable 25(OH)D were observed on the prediction of PTH and BMD in the multiple linear regression models. Conclusion Our study presents the distribution of 24,25(OH)2D concentration and VMR in Korean population for the first time. Overall, our data reaffirm that 25(OH)D is the primary marker for determining vitamin D status in the general population.

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Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 95%

Section: Introductionmentioning

confidence: 99%

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Serum 24,25-dihydroxyvitamin D level in general Korean population and its relationship with other vitamin D biomarkers

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“…Previous studies have consistently demonstrated that vitamin D deficiency has been considered an associated factor for tuberculosis (TB) [ 17 , 18 , 19 ]. However, studies of vitamin D status in patients with NTM-PD have been scanty and showed inconclusive results [ 20 , 21 ].…”

Section: Introductionmentioning

confidence: 99%

A Prospective Cohort Study of Bioavailable 25-Hydroxyvitamin D Levels as a Marker of Vitamin D Status in Nontuberculous Mycobacterial Pulmonary Disease

et al. 2021

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Research on vitamin D in patients with nontuberculous mycobacterial (NTM) pulmonary disease (PD) is limited. We aimed to compare the vitamin D parameters of patients with NTM-PD to those of a healthy control group, and to assess the possible predictive markers for a clinical response. We prospectively enrolled 53 patients with NTM-PD between January 2014 and December 2016. The clinical data and vitamin D indices, including total, free, bioavailable 25-(OH)D, and vitamin D binding protein (VDBP) genotyping, were measured at baseline and six months after enrollment. An external dataset of 226 healthy controls was compared with the NTM-PD group. The mean age of subjects was 53 years; 54.5% were male. The NTM-PD group was older, predominantly female, and had a lower body mass index (BMI) than the controls. The proportion of patients with vitamin D concentration <50 nmol/L was 52.8% in the NTM-PD group and 54.9% in the control group (p = 0.789). The bioavailable 25-(OH)D concentrations of the NTM-PD group and the controls were similar (6.9 nmol/L vs. 7.6 nmol/L, p = 0.280). In the multivariable analysis, bioavailable 25-(OH)D concentrations were associated with NTM-PD, adjusting for age, sex, BMI, and VDBP levels. Bioavailable 25-(OH)D concentrations were significantly associated with susceptibility to NTM-PD, but not with treatment outcomes. Lower bioavailable 25-(OH)D might be a risk factor for NTM-PD.

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“…Bioavailable and free 25(OH)D concentrations were calculated using equations reported in previous studies and based on a total 25(OH)D, VDBP, and albumin concentrations derived from the medical records. [ 27 , 28 ]…”

Section: Methodsmentioning

confidence: 99%

Correlational analysis of bone health status and vitamin D-related biomarkers in women working in agriculture

et al. 2021

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The purpose of this study was to investigate the status of bone health in women working in agriculture and analyze the associations between bone health and various vitamin D-related biomarkers. This observational study enrolled women working in agriculture (n = 210) and control occupations (n = 180). The concentration of serum total 25-hydroxy vitamin D [25(OH)D] was measured using the Elecsys Vitamin D Total Kit, and serum vitamin D-binding protein (VDBP) was measured by enzyme-linked immunosorbent assay. Along with albumin, 25(OH)D and VDBP were used to calculate the concentrations of bioavailable and free 25(OH)D. Bone mineral density (BMD) and T-score were measured at lumbar 1 to 4 and the femur neck using dual-energy X-ray absorptiometry. To identify factors affecting BMD, log-linear model and linear regression analysis were performed for statistical analysis. Agricultural women workers showed higher serum concentrations of bioavailable 25(OH)D (12.8 ± 3.7 vs 8.7 ± 5.1 ng/mL) and lower VDBP concentrations (201.8 ± 45.0 vs 216.0 ± 68.2 μg/mL) than control women. The association between these 2 vitamin D related-biomarkers and femur neck BMD were confirmed through univariable and multivariable linear model analysis. Although lumbar BMD did not differ between groups, the agricultural group displayed a lower femur BMD and a 4.3-fold increase in the risk of osteoporosis compared with the control group. Women working in agriculture showed lower femur BMD than the control group. Of the vitamin D-related biomarkers tested, bioavailable 25(OH)D and VDBP were associated with BMD. As bioavailable 25(OH)D levels are affected mainly by VDBP levels, VDBP may play a role in the lower femur neck BMD values observed in the agricultural group. Thus, the measurement of VDBP concentration might be considered a simple and non-invasive method for measuring bone health status.

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Clinical Usefulness of Bioavailable Vitamin D and Impact of GC Genotyping on the Determination of Bioavailable Vitamin D in a Korean Population

Cited by 12 publications

References 34 publications

Serum 24,25-dihydroxyvitamin D level in general Korean population and its relationship with other vitamin D biomarkers

Serum 24,25-dihydroxyvitamin D level in general Korean population and its relationship with other vitamin D biomarkers

A Prospective Cohort Study of Bioavailable 25-Hydroxyvitamin D Levels as a Marker of Vitamin D Status in Nontuberculous Mycobacterial Pulmonary Disease

Correlational analysis of bone health status and vitamin D-related biomarkers in women working in agriculture

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