Is Intact PTH a Sensitive Biochemical Indicator of Deranged Calcium Homeostasis in Vitamin D Deficiency?

Author(s):  
J P Ashby ◽  
D J Newman ◽  
M G Rinsler

Intact PTH was elevated in 38/40 Asians with reduced serum 25 hydroxyvitamin D [25(OH)D] including seven patients with normal serum calcium, phosphate and alkaline phosphatase. Changes in intact PTH were disproportionately greater than for other biochemical parameters, making it the most sensitive early indicator of deranged calcium homeostasis in vitamin D deficiency.

2019 ◽  
Vol 16 (4) ◽  
pp. 340-347
Author(s):  
Yuge Wang ◽  
Yanqiang Wang ◽  
Bingjun Zhang ◽  
Yinyao Lin ◽  
Sha Tan ◽  
...  

Background and Objective: Vitamin D deficiency is internationally recognized among the potentially modifiable risk factors for ischemic cardio-cerebrovascular diseases. However, the association between vitamin D deficiency and stroke morbidity or mortality remains insufficiently known. Our aim is to investigate their relevance to 25-hydroxyvitamin D [25(OH) D] levels and clinical severity and outcome after 3 months in first-ever ischemic stroke. Methods: Retrospective analysis of 356 consecutive patients in first-ever ischemic stroke between 2013 and 2015. Serum 25(OH) D levels were measured at baseline. Stroke severity was assessed at admission using the National Institutes of Health Stroke Scale (NIHSS) score. Functional outcome after 3 months of onset was evaluated using the modified Rankin scale (mRS). Results: Among the 356 enrolled patients, HbA1c was higher in insufficiency/deficiency group than that in the sufficiency group (6.3 ± 1.7 vs. 5.9 ± 1.1, p =0.015). The hospital stay was longer in insufficiency/deficiency group than that in the sufficiency group (11 (8-17) vs. 9.5 (7-13), p = 0.035). There was a significant inversed trend between serum 25(OH) D levels and hospital stay (OR 0.960, P = 0.031), using logistic regression. Conclusions: 25(OH)D levels are associated with glucose homeostasis, 25(OH) D contributes to increase the length of hospital stay. Low serum 25-OHD level is an independent predictor for hospital stay in first-ever ischemic stroke. Vitamin D deficiency did not predict functional outcome in the span of 3 months.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Jing Xiao ◽  
Jingyi Lv ◽  
Shiyu Wang ◽  
Yang Zhou ◽  
Lunwen Chen ◽  
...  

Abstract Background Vitamin D deficiency has been associated with type 2 diabetes (T2D) and metabolic syndrome (MS) and its components. However, it is unclear whether a low concentration of vitamin D is the cause or consequence of these health conditions. Thus, this study aimed to evaluate the association of vitamin D concentrations and its genetic risk scores (GRSs) with MS and its component diseases, such as T2D, in middle-aged and elderly participants from rural eastern China. Methods A subset of 2393 middle-aged and elderly individuals were selected from 70,458 participants of the Nantong Chronic Diseases Study of 2017–2018 in China. We used two 25-hydroxyvitamin D (25[OH]D) synthesis single-nucleotide polymorphisms (SNPs) (DHCR7-rs12785878 and CYP2R1-rs10741657) and two 25(OH) D metabolism SNPs (GC-rs2282679 and CYP24A1-rs6013897) for creating GRSs, which were used as instrumental variables to assess the effect of genetically lowered 25(OH) D concentrations on MS and T2D based on the Wald ratio. F statistics were used to validate that the four SNPs genetically determined 25(OH) D concentrations. Results Compared to vitamin D sufficient individuals, individuals with vitamin D insufficiency had an odds ratio (OR [95% confidence interval {CI}]) of MS of 1.30 (1.06–1.61) and of T2D of 1.32 (1.08–1.64), individuals with vitamin D deficiency had an ORs (95% CI) of MS of 1.50 (1.24–1.79) and of T2D of 1.47 (1.12–1.80), and those with vitamin D severe deficiency had an ORs (95% CI) of MS of 1.52 (1.29–1.85) and of T2D of 1.54 (1.27–1.85). Mendelian randomization analysis showed a 25-nmol/L decrease in genetically instrumented serum 25(OH) D concentrations using the two synthesis SNPs (DHCR7 and CYP2R1 genes) associated with the risk of T2D and abnormal diastolic blood pressure (DBP) with ORs of 1.10 (95%CI: 1.02–1.45) for T2D and 1.14 (95%CI: 1.03–1.43) for DBP. Conclusions This one sample Mendelian randomization analysis shows genetic evidence for a causal role of lower 25(OH) D concentrations in promoting of T2D and abnormal DBP in middle-aged and elderly participants from rural China.


2021 ◽  
Vol 53 (02) ◽  
pp. 105-111
Author(s):  
Dongdong Zhang ◽  
Cheng Cheng ◽  
Yan Wang ◽  
Yuan Xue ◽  
Yiming Liu ◽  
...  

AbstractThere is a paucity of data on the relation between serum 25-hydroxyvitamin D [25(OH)D] concentration and cardiometabolic biomarkers in the Chinese population. To comprehensively and quantitatively examine the association of 25(OH)D and cardiometabolic traits, we conducted a cross-sectional study in the Chinese rural population. Serum 25(OH)D and eight cardiometabolic biomarkers were measured in 1714 individuals from Henan province, China. Scatter plot was used to visualize the distribution and correlation of 25(OH)D and cardiometabolic indicators. Moreover, multivariate linear regressions and restricted cubic spline (RCS) functions were performed to examine the quantitative association between the serum 25(OH)D and cardiometabolic parameters. The median serum 25(OH)D level was 19.94 ng/ml in all participants, with an estimated 50.12% presenting vitamin D deficiency. Serum 25(OH)D level showed significantly modest association with cardiometabolic parameters (p<0.05) except for diastolic blood pressure (r=0.03, p=0.22). Multiple linear regression models showed that 25(OH)D concentration was positively associated with high-density lipoprotein cholesterol (HDL-C) and negatively associated with low-density lipoprotein cholesterol (LDL-C) and fasting serum glucose (GLU). The results of restricted cubic spline models indicated a positively linear association of 25(OH)D with HDL-C (p for overall<0.001, p for nonlinearity=0.191) and a negatively linear association with GLU (p for overall=0.024, p for nonlinearity=0.095). Overall, vitamin D deficiency was very common among Chinese rural population living near the 34 degrees north latitude. Besides, there were significant association between 25(OH)D concentrations and cardiometabolic biomarkers including HDL-C and GLU levels. Future longitudinal studies and randomized trials are warranted to clarify the causal relationship.


2005 ◽  
Vol 34 (1) ◽  
pp. 237-245 ◽  
Author(s):  
I Hendrix ◽  
P H Anderson ◽  
J L Omdahl ◽  
B K May ◽  
H A Morris

The enzyme 25-hydroxyvitamin D 1α-hydroxylase, or CYP27B1, is the key enzyme in the two-step activation process of vitamin D to 1,25-dihydroxyvitamin D (1,25D). While a number of regulators of the renal CYP27B1 enzyme activity have been recognized for some years, their underlying molecular mechanisms remain largely unknown, and the DNA regions involved in the in vivo regulation of gene expression by these factors have not been delineated. We have generated a transgenic mouse line that expresses 1501 bp of 5′ flanking region together with 44 bp of 5′ untranslated region of the human CYP27B1 gene fused to the firefly luciferase reporter gene. Animals expressing the luciferase gene demonstrated that both luciferase protein and mRNA for CYP27B1 were localized to proximal convoluted tubule cells of the kidney. In 2-week-old animals, the expression of the transgene and the endogenous CYP27B1 mRNA levels in the kidney were highest and fell with increasing age. Both reporter gene expression and CYP27B1 mRNA levels were downregulated in response to increasing amounts of dietary calcium in a dose-dependent manner. Vitamin D deficiency resulted in an increase in both the reporter gene and CYP27B1 expression. Interestingly, the increase in CYP27B1 mRNA levels was substantially higher than the increase in reporter gene expression, suggesting either that there is a post-transcriptional mechanism that increases the amount of CYP27B1 mRNA or that other regulatory elements are required to maximize the effect of vitamin D deficiency. These findings demonstrate that the 1501 bp 5′ flanking region of the CYP27B1 gene directs expression to the proximal convoluted tubules of the kidney and is responsible for increasing transcriptional activity when dietary calcium and vitamin D levels are depleted. It also responds in the kidney to the physiological regulators of development and ageing.


2020 ◽  
Vol 13 (1) ◽  
pp. 82
Author(s):  
Aidah Juliaty ◽  
Putri Lestari Gabrilasari ◽  
Dasril Daud ◽  
Johan Setyawan Lisal

INTRODUCTION: Obesity represents the major risk factor for development of insulin resistance during childhood and adolescents. In obesity, adipose tissue release free fatty acids, various hormones, and cytokines, resulting in insulin resistance. This study aimed to establish the correlation between vitamin D deficiency and the incidence of insulin resistance in obese children. DESIGN AND METHOD: This analytical cross-sectional study was arranged from December 2019 - February 2020 included 96 students aged 11 - 17 years old from junior and senior high school who met the criteria for obesity in Makassar. The study subjects were parted into two groups, obese children with vitamin D deficiency (levels of 25-hydroxyvitamin D &le; 20 ng/ml) and obese children without vitamin D deficiency group (levels of 25-hydroxyvitamin D &gt; 20 ng/ml). Data were analyzed using univariate and bivariate analysis. RESULTS: The frequency of insulin resistance in obese children with vitamin D deficiency was 28 (54.9%), while obese children without vitamin D deficiency was 10 (22.2%). Based on statistical analysis, the frequency of the occurrence of insulin resistance in vitamin D deficiency obese children was higher than in obese children without vitamin D deficiency with OR = 4.261 (95% CI 1.744 &ndash; 10.411), p = 0.001. CONCLUSION: The risk of insulin resistance in obese children with vitamin D deficiency is 4.261 times higher than obese children without vitamin D deficiency.


2021 ◽  
Vol 2021 ◽  
pp. 1-6
Author(s):  
Naowanit Nata ◽  
Jessada Kanchanasinitth ◽  
Pamila Tasanavipas ◽  
Ouppatham Supasyndh ◽  
Bancha Satirapoj

Background. Vitamin D deficiency is a common problem among patients on continuous ambulatory peritoneal dialysis (CAPD). Vitamin D supplementation leads to reduced serum parathyroid hormone levels and improved cardiovascular markers. Different doses and time intervals of oral vitamin D supplementation may differ in each patient on dialysis. The study aimed to evaluate the efficacy of weekly split and single dose of ergocalciferol at 60,000 IU on serum 25-hydroxyvitamin D (25(OH)D) among patients on CAPD. Methods. A randomized study was conducted among patients on CAPD with vitamin D deficiency or insufficiency (25(OH)D < 30 ng/mL). Patients were randomly assigned to two groups: the split dose group was given ergocalciferol 20,000 IU three times weekly and the single dose group was given ergocalciferol 60,000 IU once weekly for 8 weeks. Main outcomes measured serum 25(OH)D concentrations, serum calcium, serum phosphate, and intact parathyroid levels at 8 weeks after being enrolled. Results. Of 128 screened patients, 50 met the criteria for eligibility and were randomized. At 8 weeks after treatment, mean serum 25(OH)D concentrations significantly increased from baseline 22.7 ± 5.9 to 29.5 ± 9.5 ng/mL P = 0.004 in the split dose group and 22.9 ± 5.3 to 31.2 ± 12.3 ng/mL P = 0.003 in the single dose group. No significant change was found in increase of serum 25(OH)D between the two groups P = 0.561 . At the end of study, a similar proportion of patients in both groups reached the desirable serum concentration of 25(OH)D ≥ 30 ng/mL (60% in the single group vs. 40% in the split group, P = 0.258 ). No significant cases of hypercalcemia, hyperphosphatemia, or serious adverse events occurred during the study. Conclusion. Weekly single and split doses of ergocalciferol 60,000 IU achieved similar effects on serum 25(OH)D levels among patients on CAPD with vitamin D insufficiency or deficiency, suggesting that weekly single dose would be prescribed for adequate vitamin D repletion. This trial is registered with TCTR20200821005.


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