Extraskeletal effects of vitamin D

Innovative Machine Learning Strategies for Early Detection and Prevention of Pregnancy Loss: The Vitamin D Connection and Gestational Health

Early pregnancy loss (EPL) is a prevalent health concern with significant implications globally for gestational health. This research leverages machine learning to enhance the prediction of EPL and to differentiate between typical pregnancies and those at elevated risk during the initial trimester. We employed different machine learning methodologies, from conventional models to more advanced ones such as deep learning and multilayer perceptron models. Results from both classical and advanced machine learning models were evaluated using confusion matrices, cross-validation techniques, and analysis of feature significance to obtain correct decisions among algorithmic strategies on early pregnancy loss and the vitamin D serum connection in gestational health. The results demonstrated that machine learning is a powerful tool for accurately predicting EPL, with advanced models such as deep learning and multilayer perceptron outperforming classical ones. Linear discriminant analysis and quadratic discriminant analysis algorithms were shown to have 98 % accuracy in predicting pregnancy loss outcomes. Key determinants of EPL were identified, including levels of maternal serum vitamin D. In addition, prior pregnancy outcomes and maternal age are crucial factors in gestational health. This study's findings highlight the potential of machine learning in enhancing predictions related to EPL that can contribute to improved gestational health outcomes for mothers and infants.

Association of rs2282679 polymorphism in vitamin D binding protein gene (GC) with the risk of vitamin D deficiency in an iranian population: season-specific vitamin D status

BACKGROUND

Genome-wide association studies in Western countries indicate a considerable impact of variations in vitamin D binding protein (GC) genes on serum concentrations of 25-hydroxyvitamin D (25(OH)D). We aimed to investigate an association between rs2282679 polymorphism in GC and vitamin D deficiency.

METHODS

A cross-sectional study conducted in the framework of the Tehran Cardio-Metabolic Genetic Study (TCGS) cohort. A total of 1568 participants aged > 18 years were randomly selected, and their 25(OH) D concentration was measured. Vitamin D deficiency was assessed concerning rs2282679 by descriptive and multivariate analysis, odds ratio (OR), and 95% confidence intervals (95%CI) calculated. Since the interaction term between rs2282679 and recruitment season was significant, we performed regression analysis separately for individuals whose blood was taken in high sunny and those whose blood was drawn in the low sunny season.

RESULTS

The rs2282679 polymorphism was in Hardy-Weinberg equilibrium (P > 0.05) in the studied population. The serum concentration of 25(OH) D median was 15.0 ng/mL, and the prevalence of VDD was 27.8%. The presence of the G allele in rs2282679 increases the risk of VDD in additive (OR = 1.35, 95% CI: 1.06-1.73) and dominant (OR = 1.33, 95% CI: 1.06-1.68) genetic models. After separating participants based on the recruitment season, the unfavorable association was observed in the additive and dominant only in the low sunny season.

CONCLUSION

The finding of the current study indicates that the GC rs2282679 SNP is associated with vitamin D deficiency. It seems that the impact of risk allele increased in the low sunny season when UV exposure has been declined.

Vitamin D deficiency and hyperglycemia in male rotating shift workers: A disturbed circadian rhythms influence

BACKGROUND

Shift work is related to several negative impacts on the health of workers. This study aimed to evaluate the association between vitamin D deficiency (VDD) and hyperglycemia in shift workers.

METHODOLOGY

This cross-sectional study included male rotating shift workers in an iron ore extraction company. Participants were classified as VDD when 25(OH)D < 20 ng/mL for a healthy population and 25(OH)D < 30 ng/mL for groups at risk for VDD. Hyperglycemia was classified when fasting glucose ≥100 mg/dL or HbA1c ≥ 5.7%. Data were compared using chi-square analysis with Cramer's V as effect size, and Bonferroni correction. Multivariate logistic regression, from a model of determination, was performed to investigate whether VDD was associated with hyperglycemia.

RESULTS

The study evaluated 1411 workers, most workers were aged 30-39 years (53.2%), and 77.5% self-declared as black, brown, with up to complete high school (71.4%) and working alternate shifts for more than 5 years (76.1%). Regarding glucose and vitamin D, 32.0% and 29.1% of the workers had hyperglycemia and VDD, respectively. In multivariate analysis, controlled for confounding factors, workers with VDD had a 119% increased chance of hyperglycemia (OR: 2.19; IC95%: 1.56-3.08). Furthermore, vitamin D levels in distribution quintiles showed a dose-response gradient in relation to hyperglycemia, where increased vitamin D values were associated with a reduction in the occurrence of hyperglycemia.

CONCLUSION

Rotating shift workers with vitamin D deficiency are more likely to have hyperglycemia.

Association of vitamin D levels and polymorphisms in vitamin D receptor with type 2 diabetes mellitus

Type 2 diabetes mellitus (T2DM) is a leading cause of death. The prevalence of T2DM in countries of the Middle East and North Africa (MENA) region, including Jordan, is among the highest worldwide. The reason(s) behind the epidemic nature of T2DM in Jordan are unknown but warrant further exploration. Studies have indicated that T2DM could be influenced by diet and/or genetic background. Evidence suggests that numerous patients with T2DM are deficient in vitamin D. The activity of vitamin D on its target tissues may be influenced by single nucleotide polymorphisms (SNPs) in the vitamin D receptor (VDR) gene. It was therefore hypothesized that SNPs in VDR could modify the risk of T2DM. To test this hypothesis, 125 patients with T2DM were recruited along with 125 controls. The study subjects were genotyped for variations in rs2228570, rs1544410, rs7975232, and rs731236 SNPs in the VDR. The levels of 25-hydroxyvitamin D [25(OH)D] were measured from the serum. The analysis revealed that reduced 25(OH)D and age were associated with the risk of T2DM (P<0.05). Moreover, under a dominant inheritance model, the GG genotype of rs2228570 was revealed to increase the risk of T2DM in univariate and multivariate analysis (P<0.05). Additionally, a chromosomal block containing the GAAG haplotype of VDR SNPs increased the risk of T2DM (OR=1.909; CI: 1.260-2.891; P=0.0021). Collectively, the present study revealed that low levels of serum 25(OH)D and rs2228570 of the VDR gene are associated with the risk of T2DM.

Effects of dietary vitamin D3 supplementation on the growth performance, tissue Ca and P concentrations, antioxidant capacity, immune response and lipid metabolism in Litopenaeus vannamei larvae

An 8-week feeding trial was conducted to investigate the effects of dietary vitamin D3 supplementation on the growth performance, tissue Ca and P concentrations, antioxidant capacity, immune response and lipid metabolism in Litopenaeus vannamei larvae. A total of 720 shrimp (initial weight 0·50 ± 0·01 g) were randomly distributed into six treatments, each of which had three duplicates of forty shrimp per duplicate. Six isonitrogenous and isolipidic diets were formulated to contain graded vitamin D3 (0·18, 0·23, 0·27, 0·48, 0·57 and 0·98 mg/kg of vitamin D3, measured) supplementation levels. The results revealed that L. vannamei fed diet containing 0·48 mg/kg of vitamin D3 achieved the best growth performance. Compared with the control group, supplementing 0·48 mg/kg of vitamin D3 significantly increased (P < 0·05) the activities of catalase, total antioxidative capacity, alkaline phosphatase and acid phosphatase in serum and hepatopancreas. Expression levels of antioxidant and immune-related genes were synchronously increased (P < 0·05). Carapace P and Ca concentrations were increased (P < 0·05) with the increased vitamin D3 supplementation levels. Further analysis of lipid metabolism-related genes expression showed that shrimp fed 0·48 mg of vitamin D3 per kg diet showed the highest value in the expression of lipid synthesis-related genes, while shrimp fed 0·98 mg of vitamin D3 per kg diet showed the highest value in the expression of lipolysis-related genes. In conclusion, the results of present study indicated that dietary supplementation of 0·48 mg/kg of vitamin D3 could increase Ca and P concentrations, improve antioxidant capacity and immune response, and influence lipid metabolism in L. vannamei.

Experimental study protocol of the project "MOtor function and VItamin D: Toolkit for motor performance and risk Assessment (MOVIDA)"

Musculoskeletal injuries, a public health priority also in the military context, are ascribed to several risk factors, including: increased reaction forces; low/reduced muscle strength, endurance, body mass, Vitamin D level, and bone density; inadequate lifestyles and environment. The MOVIDA Project-funded by the Italian Ministry of Defence-aims at developing a transportable toolkit (assessment instrumentation, assessment protocols and reference/risk thresholds) which integrates motor function assessment with biological, environmental and behavioural factors to help characterizing the risk of stress fracture, stress injury or muscle fatigue due to mechanical overload. The MOVIDA study has been designed following the STROBE guidelines for observational cross-sectional studies addressing healthy adults, both militaries and civilians, with varying levels of physical fitness (sedentary people, recreational athletes, and competitive athletes). The protocol of the study has been designed and validated and is hereby reported. It allows to collect and analyse anamnestic, diagnostic and lifestyle-related data, environmental parameters, and functional parameters measured through portable and wearable instrumentation during adapted 6 minutes walking test. The t-test, one and two-way ANOVA with post-hoc corrections, and ANCOVA tests will be used to investigate relevant differences among the groups with respect to biomechanical parameters; non-parametric statistics will be rather used for non-normal continuous variables and for quantitative discrete variables. Generalized linear models will be used to account for risk and confounding factors.

Vitamin D Supplementation Induces Cardiac Remodeling in Rats: Association with Thioredoxin-Interacting Protein and Thioredoxin

BACKGROUND

Vitamin D (VD) has been shown to play an important role in cardiac function. However, this vitamin exerts a biphasic "dose response" curve in cardiovascular pathophysiology and may cause deleterious effects, even in non-toxic doses. VD exerts its cellular functions by binding to VD receptor. Additionally, it was identified that the thioredoxin-interacting protein (TXNIP) expression is positively regulated by VD. TXNIP modulate different cell signaling pathways that may be important for cardiac remodeling.

OBJECTIVE

To evaluate whether VD supplementation lead to cardiac remodeling and if TXNIP and thioredoxin (Trx) proteins are associated with the process.

METHODS

A total of 250 Male Wistar rats were allocated into three groups: control (C, n=21), with no VD supplementation; VD3 (n = 22) and VD10 (n=21), supplemented with 3,000 and 10,000 IU of VD/ kg of chow respectively, for two months. The groups were compared by one-way analysis of variance (ANOVA) and Holm-Sidak post hoc analysis, (variables with normal distribution), or by Kruskal-Wallis test and Dunn's test post hoc analysis. The significance level for all tests was 5%.

RESULTS

TXNIP protein expression was higher and Trx activity was lower in VD10. The animals supplemented with VD showed increased lipid hydroperoxide and decreased superoxide dismutase and glutathione peroxidase. The protein Bcl-2 was lower in VD10. There was a decrease in fatty acid β-oxidation, tricarboxylic acid cycle and electron transport chain with shift to increase in glycolytic pathway.

CONCLUSION

VD supplementation led to cardiac remodeling and this process may be modulated by TXNIP and Trx proteins and consequently oxidative stress.

Overuse-Related Injuries of the Musculoskeletal System: Systematic Review and Quantitative Synthesis of Injuries, Locations, Risk Factors and Assessment Techniques

Overuse-related musculoskeletal injuries mostly affect athletes, especially if involved in preseason conditioning, and military populations; they may also occur, however, when pathological or biological conditions render the musculoskeletal system inadequate to cope with a mechanical load, even if moderate. Within the MOVIDA (Motor function and Vitamin D: toolkit for risk Assessment and prediction) Project, funded by the Italian Ministry of Defence, a systematic review of the literature was conducted to support the development of a transportable toolkit (instrumentation, protocols and reference/risk thresholds) to help characterize the risk of overuse-related musculoskeletal injury. The PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) approach was used to analyze Review papers indexed in PubMed and published in the period 2010 to 2020. The search focused on stress (overuse) fracture or injuries, and muscle fatigue in the lower limbs in association with functional (biomechanical) or biological biomarkers. A total of 225 Review papers were retrieved: 115 were found eligible for full text analysis and led to another 141 research papers derived from a second-level search. A total of 183 papers were finally chosen for analysis: 74 were classified as introductory to the topics, 109 were analyzed in depth. Qualitative and, wherever possible, quantitative syntheses were carried out with respect to the literature review process and quality, injury epidemiology (type and location of injuries, and investigated populations), risk factors, assessment techniques and assessment protocols.

Association Between Vitamin D, Frailty, and Progression of Frailty in Community-Dwelling Older Women

CONTEXT

Vitamin D (25OHD) is involved in many physiological functions that decline with age, contributing to frailty and increased risk for negative health outcomes. Whether 25OHD is a long-term risk marker for frailty over a longer time and whether it is consistent with advancing age is unclear.

OBJECTIVE

To investigate the association between 25OHD and frailty in older women followed for 10 years.

DESIGN AND SETTING

Prospective, population-based, cohort study in Malmö, Sweden.

PARTICIPANTS

Community-dwelling women, age 75 years (N = 1044) with reassessments at ages 80 (n = 715) and 85 (n = 382) years.

METHODS

Frailty was quantified using a 10-variable frailty index. Women were categorized as 25OHD insufficient (<50 nmol/L) or sufficient (≥50 nmol/L).

RESULTS

At ages 75 and 80 years, women with insufficient 25OHD were frailer than women with sufficient 25OHD (0.23 vs 0.18, P < 0.001; and 0.32 vs 0.25, P = 0.001, respectively). At age 80 years, 25OHD insufficiency was associated with subsequent frailty 5 years later (0.41 vs 0.32; P = 0.011). Accelerated progression of frailty was not associated with lower 25OHD levels, and 25OHD level >75 nmol/L was not additionally beneficial with regard to frailty. No association between 25OHD and frailty was observed at age 85 years. Within the frailty index, variables associated with 25OHD were related to muscle strength and function.

CONCLUSION

In this study, 25OHD insufficiency was associated with increased frailty in all but the oldest old. This study supports the value of maintaining sufficient 25OHD levels for healthy aging.

Serum vitamin D3 levels are not associated with thyroid cancer prevalence in euthyroid subjects without autoimmune thyroid disease

BACKGROUND/AIMS

Previous studies have suggested that elevated serum vitamin D levels might protect against thyroid cancer. Elevated serum thyroid stimulating hormone levels and autoimmune thyroid disease (AITD) are suggested to be thyroid cancer promoting factors but have not been well controlled in previous studies. We designed the present study to evaluate whether serum vitamin D levels are associated with thyroid cancer in euthyroid patients with no clinical evidence of AITD.

METHODS

This cross-sectional study included subjects who underwent routine health check-ups, including serum 25-hydroxy vitamin D3 (25(OH)D3) levels, anti-thyroid peroxidase antibody (TPO-Ab), and thyroid ultrasonography (US). Inclusion criteria were euthyroid, negative TPO-Ab, and no evidence of AITD by US findings. Thyroid cancer diagnoses were based on fine needle aspiration cytology and/or postsurgical histopathological findings.

RESULTS

We enrolled 5,186 subjects (64% male, 37% female) in this study, including 53 patients (1%) with a diagnosis of thyroid cancer (33 males, 20 females). Mean 25(OH)D3 levels were similar between the thyroid cancer and control groups (p = 0.20). Subgroup analysis according to sex or seasonal variation also revealed no differences in 25(OH)D3 levels between the two groups. Based on the levels of 25(OH)D3, there was no significant difference in the prevalence of thyroid cancer; the prevalence was 0.71%, 0.94%, 1.40%, and 0.82% in the deficient, insufficient, sufficient, and excess groups, respectively (p = 0.64).

CONCLUSIONS

The levels of serum 25(OH)D3 are not associated with thyroid cancer prevalence in euthyroid subjects with no clinical evidence of AITD.

Vitamin D Levels in Patients With Type 2 Diabetes Mellitus

BACKGROUND

Vitamin D may influence many diseases, including type 2 diabetes mellitus.

PATIENTS AND METHODS

We studied serum levels of 25-hydroxyvitamin D (25(OH)D) and associated characteristics in type 2 diabetic outpatients with pharmacologic treatment attended in internal medicine offices in a first-level hospital from Extremadura (Southern Spain).

RESULTS

We included a total of 103 patients. Seventy-two patients (69.9%) had serum levels of 25(OH)D lower than 20 ng/mL. There was inverse correlation between serum levels of 25(OH)D and glycosylated hemoglobin (r = -0.74, P = 0.01). In 78 patients without insulin therapy, we found inverse correlation between serum levels of 25(OH)D and fasting serum insulin (r = -0.82, P = 0.001) and Homeostasis Model Assessment-Insulin Resistance (r = -0.51, P < 0.001).

CONCLUSIONS

Vitamin D deficiency is common in type 2 diabetic patients. There are inverse correlations between vitamin D and metabolic control and insulin resistance.

Effect of a transcriptional inactive or absent vitamin D receptor on beta-cell function and glucose homeostasis in mice

Vitamin D deficiency is associated with beta-cell dysfunction and a higher risk of diabetes, but mice and humans with an absence of the vitamin D receptor (VDR) display normal glucose tolerance. Here, we investigated the direct effects of absence of VDR or absence of ligand activation of VDR on beta-cell function. For this purpose, we generated mice, with a mutation in the AF2 domain of Vdr (VDRΔAF2), preventing ligand-driven transcriptional activation of vitamin D responsive genes. VDRΔAF2 mice were compared to Vdr full knockout (VDR^-/-) and wild type (WT) mice. In order to avoid hypocalcemia, which has a direct effect on beta-cell function, mice were fed a high calcium, high lactose diet yielding comparable serum calcium in all mice. While VDR^-/- mice developed extensive alopecia by the age of 24 weeks, the fur of VDRΔAF2 remained normal. All VDRΔAF2 mice weighed significantly less than WT, while male but not female VDR^-/- mice had a lower body weight than WT mice. Dual-energy X-ray absorptiometry showed that both VDRΔAF2 (17.2% (females) and 16.6% (males)) and VDR^-/- (15.7% and 14.8%) mice have a lower percentage of body fat (vs 19.3% and 22.2% in WT). Serum 25(OH)D₃ concentrations were lower for both VDRΔAF2 (-4.55 fold, P<0.001) and VDR^-/- (-3.7 fold, P<0.001) as compared to 12 week old WT mice, while serum 1,25(OH)₂D₃ was increased for both strains 94.5 fold (P<0.01) and 92.8 fold (P<0.001) for VDRΔAF2 and VDR^-/- vs WT, respectively). In vivo glucose tolerance tests performed at 12 and 24 weeks of age, as well as ex vivo glucose stimulated insulin secretion on freshly isolated islets, revealed no major differences between the three strains. Microarray analysis on freshly isolated islets showed only 1 differentially expressed gene, phosphodiesterase 10a (Pde10a), which was 2.16 and 1.75 fold up-regulated in VDRΔAF2 and VDR^-/- islets as compared to WT islets, respectively (P≤0.001). We conclude that in the presence of normocalcemia, absence of VDR or its ligand-activated transcription of genes has no direct regulatory effect on murine glucose homeostasis or gene expression in islets of Langerhans.

Age, serum 25-hydroxyvitamin D and vitamin D receptor (VDR) expression and function in peripheral blood mononuclear cells

The relationship between age, vitamin D status, expression and functionality of the vitamin D receptor (VDR), and key genes in the vitamin D pathway in immune cells is unclear. We enrolled adults 50 to 69 years old (20 subjects) and 70+ (20 subjects) and measured: 1) 25(OH)D levels by liquid chromatography/mass spectrometry; and 2) mRNA expression of VDR, 1α-OHase, 1,25D3-MARRS, TREM-1, cathelicidin, RIG-I, and interferon-β by qRT-PCR. Mean serum 25(OH)D was 30 ± 4 ng/mL and was not associated with age. Baseline expression of VDR, 1α-OHase, 1,25D3-MARRS, TREM-1, and RIG-I also did not differ by age; IFN-β expression, however, was higher in the 70+ year old group. 25(OH)D3- and 1,25(OH)2D3-induced VDR, TREM-1 and cathelicidin expression were similar between age groups, as was LPS-induced expression of VDR and of 1α-OHase. Ligand-induced 1,25D3-MARRS expression was higher in subjects ≥ 70 years. Serum 25(OH)D was inversely associated with LPS-stimulated VDR expression and with baseline or vitamin D-induced TREM-1 expression, adjusting for age, self-rated health, and functional status. In healthy adults ≥ 50 years, the expression and functionality of the VDR, 1α-OHase and key vitamin D pathway genes were not consistently associated with age.

Metabolic effects of vitamin D supplementation in vitamin D deficient patients (a double-blind clinical trial)

BACKGROUND

Vitamin D has recently been given a lot of attention for its role in controlling insulin secretion. Many studies have spoken of its role in weight management, blood sugar control and many other metabolic variables.

PATIENT AND METHODS

In a randomized double-blind clinical trial, 210 people with vitamin D deficiency were randomly allocated into two groups receiving vitamin D (50,000 units per week) or placebo for 8 weeks.

RESULTS

Vitamin D levels were significantly increased in the group receiving vitamin D supplementation (13.7±5.2 unit increase versus 0.8±2.8). The increased levels of vitamin D lead to significant changes in fasting insulin levels (6.8±8.1 unit reduction versus 2.3±3.7), a 2-h insulin (31.1±34.9 unit reduction versus 4.5±24.6) and Homeostasis Model Assessment (HOMA) indices.

CONCLUSION

Correction of vitamin D deficiency leads to increased insulin sensitivity that was significantly able to maintain glucose in the normal range with lower levels of insulin.

Metabolic effects of supplementation with vitamin D in type 2 diabetic patients with vitamin D deficiency

AIM

Epidemiological studies suggest that vitamin D status influences type 2 diabetes mellitus. We investigate the metabolic effects of vitamin D.

MATERIAL AND METHODS

We studied consecutive type 2 diabetic patients without insulin therapy with vitamin D deficiency (serum 25-hydroxyvitamin D (25(OH)D) lower than 20ng/ml). They were treated with 16,000IU of calcifediol orally once a week for a minimum of 8 weeks.

RESULTS

Twenty eight patients were treated for a mean time of 84.1 days (range 56 to 120 days). All patients achieved serum levels of 25(OH)D higher than 20ng/ml. There was a significant reduction in fasting glucose (145.6±35.5 vs. 131.7±30.4mg/dl, p<0.001). There were small non-significant reductions in HbA1c, fasting insulin and Homeostasis Model Assesment (HOMA)-insulin resistance (IR). There were small non-significant increases in HOMA-insulin sensitivity (S) and HOMA-beta cell function (B) and a small significant increase in Quantitative Insulin Sensitivity Check Index (QUICKI).

CONCLUSIONS

Correction of vitamin D deficiency in type 2 diabetic patients decreases fasting glucose. Our results do not rule out improvements in metabolic control, insulin-resistance and function of the beta cell.

Polymorphic variants in the vitamin D pathway genes and the risk of ovarian cancer among non-carriers of BRCA1/BRCA2 mutations

Previous studies have produced inconsistent results regarding the contribution of single-nucleotide polymorphisms (SNPs) in the vitamin D receptor (VDR) gene to ovarian cancer (OC) in various ethnicities. Additionally, little has been established with regard to the role of SNPs located in the retinoid X receptor α (RXRA), vitamin D-binding protein [also know as group-specific component (GC)] and VDR genes in non-carriers of the breast cancer 1/2 early onset (BRCA1/BRCA2) gene mutations. All participating individuals in the present study were evaluated for BRCA1 mutations (5382incC, C61G and 4153delA) with HybProbe assays, and for BRCA2 mutation (5946delT) using high-resolution melting (HRM) analysis. The associations of 8 SNPs located in RXRA, GC and VDR were investigated in OC patients without the BRCA1/BRCA2 mutations (n=245) and healthy controls (n=465). Genotyping of RXRA rs10881578 and rs10776909, and GC rs1155563 and rs2298849 SNPs was conducted by HRM analysis, while RXRA rs749759, GC rs7041, VDR BsmI rs1544410 and FokI rs2228570 genotyping was performed by polymerase chain reaction-restriction fragment length polymorphism analysis. In addition, the gene-gene interactions among all tested SNPs were studied using the epistasis option in PLINK software. The lowest P-values of the trend test were identified for VDR rs1544410 and GC rs2298849 as P_trend=0.012 and P_trend=0.029, respectively. It was also found that, in the dominant inheritance model, VDR BsmI contributed to an increased risk of OC [odds ratio (OR), 1.570; 95% confidence interval (CI), 1.136-2.171; P=0.006; P_corr=0.048]. The gene-gene interaction analysis indicated a significant interaction between RXRA rs749759 and VDR FokI rs2228570 (OR for interaction, 1.687; χ²=8.278; asymptotic P-value=0.004; P_corr=0.032). In conclusion, this study demonstrated that certain VDR and RXRA SNPs may be risk factors for OC in non-carriers of BRCA1/BRCA2 mutations in the Polish population.

Effects on lipid profile of supplementation with vitamin D in type 2 diabetic patients with vitamin D deficiency

BACKGROUND

Epidemiological studies suggest that vitamin D status may have an influence on lipid profile.

PATIENTS AND METHODS

We studied consecutive type 2 diabetic patients with vitamin D deficiency (serum 25-hydroxyvitamin D (25(OH)D) lower than 20 ng/ml). They were treated with 16,000 IU of calcifediol orally once a week for a minimum of 8 weeks.

RESULTS

A total of 28 patients were treated for a mean time of 84.1 days (range 56-120 days). All patients achieved serum levels of 25(OH)D higher than 20 ng/ml. There was significant reduction in total cholesterol (172.1 ± 32.4 versus 164.4 ± 27.3 mg/dl, p = 0.04). There were nonsignificant reductions in low-density lipoprotein (LDL) cholesterol, non-high-density lipoprotein (non-HDL) cholesterol and triglycerides. There was no change in HDL cholesterol.

CONCLUSIONS

Correction of vitamin D deficiency in type 2 diabetic patients decreases total cholesterol. Our results do not rule out reductions in LDL cholesterol, non-HDL cholesterol and triglycerides.

The vitamin D status and its effects on life quality among the elderly in Jinan, China

A challenge for researchers is that vitamin D has many functions in the body, and vitamin D status across the world is not optimistic. There was little data regarding insufficient vitamin D status and its adverse effect on health of elderly Chinese people. So we selected 686 subjects (310 men and 376 women) aged 60-89 years to explore the correlation between vitamin D status and their life quality in a community-based osteoporosis prevention study at Qianfoshan Hospital of Shandong University from 2009 to 2010. All subjects were divided into three groups: vitamin D adequacy [serum 25(OH)D ≧ 75 nmol/L], hypovitaminosis D (50-74.9 nmol/L), and vitamin D insufficiency (<50 nmol/L). Participants were requested to complete SF-36 health survey. The regression models were used to evaluate respectively the association between 25(OH)D levels and parameters of SF-36. As a result, serum 25(OH)D levels were 58.60 nmol/L in male [95% confidence interval (95% CI): 56.7-60.5 nmol/L] and 54.17 nmol/L in female (95% CI: 52.8-55.8 nmol/L). Vitamin D adequacy was in 19.4% of male and 14.4% of female. With aging, proportions of insufficient vitamin D increased significantly in male (P=0.004), and in female (P<0.001). The elderly with hypovitaminosis D got lower scores than that with vitamin D adequacy (almost P<0.01). Regression analysis showed that vitamin D appeared a positive association with parameters of SF-36 (almost P<0.001). In conclusion, vitamin D status in the elderly was severely inadequate, which decreased their life quality and cause adverse effect on their health.

Maternal-fetal impact of vitamin D deficiency: a critical review

Research into the extra-skeletal functions of vitamin D has been expanding in recent years. During pregnancy, maternal vitamin D status may be of concern because of the key role of this vitamin in fetal skeletal development and due to the association between hypovitaminosis D and adverse maternal-fetal outcomes. Therefore, the objective of this manuscript was to review the maternal-fetal impact of gestational vitamin D deficiency and the benefits of vitamin D supplementation during pregnancy. A literature search was performed in PubMed and Embase employing the following keywords: vitamin D deficiency, pregnancy, 25-hydroxyvitamin D, and hypovitaminosis D. All relevant articles in English language published since 1980 were analysed by the two authors. Neonatal complications derived from vitamin D deficiency include low birth weight, growth restriction, and respiratory tract infection. In the mother, vitamin D deficiency has been associated with altered glucose homeostasis and increased incidence of gestational diabetes mellitus, pre-eclampsia, and bacterial vaginosis. However, the current state of the evidence is controversial for some other endpoints and the actual benefit of vitamin D supplementation in pregnancy remains unclear. Additional longitudinal studies may clarify the actual impact of vitamin D deficiency during pregnancy, and randomised trials are required to define the benefits of vitamin D supplementation in reducing the incidence of adverse outcomes in the mother and infant.

Vitamin D supplementation and testosterone concentrations in male human subjects

OBJECTIVE

A possible association between serum 25-hydroxyvitamin D and testosterone levels has been reported; however, contradictory results have emerged.

DESIGN

To investigate a causal link between vitamin D and testosterone status, we studied the effect of vitamin D supplementation on serum testosterone concentrations in three independent intervention studies including male patients with heart failure (study 1), male nursing home residents (study 2) and male non-Western immigrants in the Netherlands (study 3).

METHODS

In study 1, 92 subjects were randomized to either vitamin D (2000 IU cholecalciferol daily) or control. Blood was drawn at baseline, after 3 and 6 weeks. In study 2, 49 vitamin D deficient subjects received either vitamin D (600 IU daily) or placebo. Blood was drawn at baseline, after 8 and 16 weeks. In study 3, 43 vitamin D deficient subjects received either vitamin D (1200 IU daily) or placebo. Blood was drawn at baseline, after 8 and 16 weeks. Serum 25-hydroxyvitamin D levels were measured using LC-MS/MS or radioimmunoassay. Testosterone levels were measured using a 2nd generation immunoassay.

RESULTS

Serum 25-hydroxyvitamin D levels significantly increased in all treatment groups (median increase of 27, 30 and 36 nmol/l in studies 1, 2 3, respectively) but not in the control groups. The documented increase in 25-hydroxyvitamin D levels, however, did not affect mean testosterone concentrations at the end of the study (median increase of 0, 0.5 and 0 nmol/l in studies 1, 2 and 3, respectively).

CONCLUSIONS

In this post hoc analysis of three small clinical trials of limited duration in men with normal baseline testosterone concentrations, vitamin D supplementation was not associated with an increase in circulating testosterone concentrations.

Vitamin D Levels Decline with Rising Number of Cardiometabolic Risk Factors in Healthy Adults: Association with Adipokines, Inflammation, Oxidative Stress and Advanced Glycation Markers

INTRODUCTION

Hypovitaminosis D associates with obesity, insulin resistance, hypertension, and dyslipoproteinemia. We asked whether the presence of multiple cardiometabolic risk factors, and which particular combination, exerts additive negative effects on 25(OH)D3 levels; and whether 25(OH)D3 levels associate with markers of inflammation and oxidative stress.

SUBJECTS AND METHODS

In non-diabetic medication-free adults central obesity (waist-to-height ratio > 0.5); elevated blood pressure (systolic BP≥130 mm Hg and/or diastolic BP ≥85 mm Hg); increased atherogenic risk (log(TAG/HDL) ≥ 0.11); and insulin resistance (QUICKI < 0.322) were considered as cardiometabolic risk factors. 25(OH)D3 status was classified as deficiency (25(OH)D3 ≤20 ng/ml); insufficiency (levels between 20-to-30 ng/ml), or as satisfactory (>30 ng/ml). Plasma adipokines, inflammatory and oxidative stress markers, advanced glycation end-products, and their soluble receptor were determined.

RESULTS

162 subjects were cardiometabolic risk factors-free, 162 presented increased (i.e. 1 or 2), and 87 high number (i.e. 3 or 4) of cardiometabolic risk factors. Mean 25(OH)D3 decreased with rising number of manifested risk factors (36 ± 14 ng/ml, 33 ± 14 ng/ml, and 31 ± 15 ng/ml, respectively; pANOVA: 0.010), while prevalence of hypovitaminosis D did not differ significantly. Elevated blood pressure and insulin resistance appeared as significant determinants of hypovitaminosis D. Subjects presenting these risk factors concurrently displayed the lowest 25(OH)D3 levels (29 ± 15 ng/ml). Plasma adipokines, inflammatory and oxidative stress markers, advanced glycation end-products, and their soluble receptor generally differed significantly between the groups, but only advanced oxidation protein products and advanced glycation end-products associated fluorescence of plasma showed significant independent association with 25(OH)D3 levels.

CONCLUSION

In apparently healthy adults increasing number of cardiometabolic risk factors associates with poorer 25(OH)D3 status, while the association between 25(OH)D3 status and inflammatory or oxidative stress markers remains equivocal.

Administration of exogenous 1,25(OH)2D3 normalizes overactivation of the central renin-angiotensin system in 1α(OH)ase knockout mice

Previously, we reported that active vitamin D deficiency in mice causes secondary hypertension and cardiac dysfunction, but the underlying mechanism remains largely unknown. To clarify whether exogenous active vitamin D rescues hypertension by normalizing the altered central renin-angiotensin system (RAS) via an antioxidative stress mechanism, 1-alpha-hydroxylase [1α(OH)ase] knockout mice [1α(OH)ase(-/-)] and their wild-type littermates were fed a normal diet alone or with 1,25-dihydroxyvitamin D3 [1,25(OH)2D3], or a high-calcium, high-phosphorus "rescue" diet with or without antioxidant N-acetyl-l-cysteine (NAC) supplementation for 4 weeks. Compared with their wild-type littermates, 1α(OH)ase(-/-)mice had high mean arterial pressure, increased levels of renin, angiotensin II (Ang II), and Ang II type 1 receptor, and increased malondialdehyde levels, but decreased anti-peroxiredoxin I and IV proteins and the antioxidative genes glutathione reductase (Gsr) and glutathione peroxidase 4 (Gpx4) in the brain samples. Except Ang II type 1 receptor, these pathophysiological changes were rescued by exogenous 1,25(OH)2D3 or NAC plus rescue diet, but not by rescue diet alone. We conclude that 1,25(OH)2D3 normalizes the altered central RAS in 1α(OH)ase(-/-)mice, at least partially, through a central antioxidative mechanism.

Classic PCOS phenotype is not associated with deficiency of endogenous vitamin D and VDR gene polymorphisms rs731236 (TaqI), rs7975232 (ApaI), rs1544410 (BsmI), rs10735810 (FokI): a case-control study of lower Silesian women

CONTEXT

The role of endogenous vitamin D and vitamin D receptor (VDR) gene polymorphism in polycystic ovary syndrome (PCOS) is still controversial.

OBJECTIVE

The objective of this study was to investigate for the first time in women with "classic" PCOS phenotype and healthy controls the role of the serum endogenous vitamin D level and VDR gene polymorphisms in PCOS etiology.

DESIGN

Ninety-two women with "classic" PCOS phenotype and 85 controls from lower Silesia with comparable body mass index (BMI) were studied. In all women the waist circumference, android/gynoid fat deposit, parameters of lipid and glucose metabolism, testosterone, free androgen index, sex hormone binding globulin (SHBG) and vitamin D were evaluated. Also, VDR gene polymorphisms rs731236, rs7975232, rs1544410 and rs10735810 were assessed.

RESULTS

Serum vitamin D levels in both groups were comparable. Also high, comparable frequencies of hypovitaminosis and vitamin D deficiency in both groups were observed. Women with "classic" PCOS phenotype had statistically significantly higher values of all measured parameters, except serum SHBG and high-density lipoprotein (HDL)-cholesterol, which were lower. The frequency of VDR genotype polymorphism was also comparable in both groups.

CONCLUSIONS

For the first time, we show that endogenous vitamin D deficiency and VDR polymorphisms are not associated with homogeneous "classic" PCOS phenotype.

Mechanisms in endocrinology: vitamin D as a potential contributor in endocrine health and disease

OBJECTIVE

It has been suggested that vitamin D may play a role in the pathogenesis of several endocrine diseases, such as hyperparathyroidism, type 1 diabetes (T1DM), type 2 diabetes (T2DM), autoimmune thyroid diseases, Addison's disease and polycystic ovary syndrome (PCOS). In this review, we debate the role of vitamin D in the pathogenesis of endocrine diseases.

METHODS

Narrative overview of the literature synthesizing the current evidence retrieved from searches of computerized databases, hand searches and authoritative texts.

RESULTS

Evidence from basic science supports a role for vitamin D in many endocrine conditions. In humans, inverse relationships have been reported not only between blood 25-hydroxyvitamin D and parathyroid hormone concentrations but also with risk of T1DM, T2DM, and PCOS. There is less evidence for an association with Addison's disease or autoimmune thyroid disease. Vitamin D supplementation may have a role for prevention of T2DM, but the available evidence is not consistent.

CONCLUSIONS

Although observational studies support a potential role of vitamin D in endocrine disease, high quality evidence from clinical trials does not exist to establish a place for vitamin D supplementation in optimizing endocrine health. Ongoing randomized controlled trials are expected to provide insights into the efficacy and safety of vitamin D in the management of endocrine disease.

Vitamin D deficiency is associated with increased mortality in critically ill patients especially in those requiring ventilatory support

INTRODUCTION

Vitamin D (VitD) classically recognized for its role in the musculoskeletal system, has been implicated in myriad of conditions such as diabetes, immune dysfunction, cancers, heart disease, metabolic syndrome, etc. We studied the role of VitD in acute care setting and its correlation with mortality.

MATERIALS AND METHODS

A total of 85 consecutive consenting patients admitted in medical intensive care unit of tertiary care hospital who fulfilled the inclusion criteria were included. All patients were evaluated clinically, and blood samples were collected for hemogram, biochemical investigations including serum calcium, phosphorus, alkaline phosphatase, magnesium, along with 25(OH) VitD, 1,25(OH) VitD and intact parathormone levels. Simplified acute physiology score (SAPS II) was calculated for all patients.

RESULTS

VitD was deficient (<30 ng/ml) in 27 patients (32%). The overall mortality was more in VitD deficient group as compared to VitD sufficient group (74 vs. 41%; P < 0.05). The actual mortality in VitD deficient group was higher than the mortality predicted by SAPS II score (50 vs. 74%; P < 0.0507). VitD deficiency was also associated with more mortality among those requiring ventilator support (95% vs. 40%; P < 0.05) as well as with higher blood glucose (124.5 ± 29.7 vs. 94.8 ± 19.8: P < 0.01) levels.

CONCLUSION

VitD deficiency was associated with increased mortality, poor ventilator outcomes, and increased blood glucose in critically ill patients.

Calcitriol supplementation improves endothelium-dependent vasodilation in rat hypertensive renal injury

BACKGROUND/AIMS

Vitamin D increases renal expression of klotho in normotensive rats. Klotho reduces oxidative stress.

METHODS

In this study, we aimed to determine if vitamin D would suppress oxidative stress using 4 groups of hypertensive rats: uninephrectomized, stroke-prone, spontaneously hypertensive rats fed a high-salt (6%) diet (controls; C); those treated with irbesartan (I); those treated with calcitriol (V); and those treated with both irbesartan and calcitriol (I+V).

RESULTS

Systolic blood pressure was higher in the C group than in the I and I+V groups. Albuminuria was attenuated in groups I, V, and I+V. Renal angiotensin II (AngII) concentration was lower in groups I and I+V than in group C, and plasma AngII levels of groups I and V were higher and lower than those in group C, respectively. Compared with group C, renal klotho expression, 8-epi-prostaglandin F2α excretion, and acetylcholine-induced decrease in blood pressure improved in the V and I+V groups.

CONCLUSIONS

The data indicate that irbesartan effectively decreases blood pressure and renal AngII levels, and improves albuminuria. Our findings indicate that vitamin D enhances klotho expression, suppressing oxidative stress and albuminuria without substantial changes in renal AngII levels. These results suggest that the amelioration of endothelium function by vitamin D involves free klotho.

Administering 25-hydroxyvitamin D3 in vitamin D-deficient young type 1A diabetic patients reduces reactivity against islet autoantigens

BACKGROUND & AIMS

We investigated whether improving 25-hydroxyvitamin D status in young type 1A diabetic patients reduces reactivity of peripheral blood mononuclear cells against islet autoantigens and associates with beta-cell functional changes.

METHODS

Eight patients with 25-hydroxyvitamin D deficiency (<20 ng/ml), out of 15 consecutive young type 1A diabetic subjects received 25-hydroxyvitamin D3 to achieve and maintain levels above 50 ng/ml for up to one year. Peripheral blood mononuclear cell reactivity (Interferon-γ spots) against beta-cell autoantigens (glutamic acid decarboxylase 65-kD isoform, proinsulin and tyrosine phosphatase-like protein IA-2) and C-peptide during mixed meal were assessed before and after 25-hydroxyvitamin D3 replenishment.

RESULTS

Target 25-hydroxyvitamin D blood levels were safely reached and maintained. Peripheral blood mononuclear cell reactivity against glutamic acid decarboxylase 65-kD isoform (3.8 ± 4.0 vs. 45 ± 16) and proinsulin (3.5 ± 3.2 vs. 75 ± 51) decreased significantly (p < 0.001 and p < 0.02) upon 25-hydroxyvitamin D3 replenishment, which was correlated with 25-hydroxyvitamin D concentrations. C-peptide values remained stable after one year of treatment.

CONCLUSIONS

Safely restored and maintained 25-hydroxyvitamin D levels associated with reduced peripheral blood mononuclear cell reactivity against beta-cell autoantigens with no significant decrease of beta-cell function in this cohort of patients.

Should vitamin D supplementation be a regular part of asthma care?

Vitamin D (vitD3) deficiency occurs frequently and has profound effects on health, especially asthma. This article examines how current knowledge of vitD3 actions and the worldwide distribution of vitD3 deficiency influences everyday clinical allergy practice. Within the limits of current knowledge, the article concisely explains the molecular nature of vitD3 actions, reviews key vitD3 research as it applies to clinical care, answers questions about the potential clinical impact of low vitD3 levels, and discusses use and safety of vitD3 supplements.

Vitamin D Measurements — Facts and Fancies

Clinical laboratories have seen an increased interest in vitamin D measurements as new knowledge about the vitamin's pathobiology escalates. Clinicians now recognise that besides bone health, vitamin D insufficiency may be associated with potential health risks such as coronary artery disease, diabetes, depression, epilepsy, polycystic ovaries, musculoskeletal pain, autoimmune disease, multiple sclerosis, and cancers. While vitamin D testing and supplementation has been touted for these patients, benefit is evident only for the prevention of falls and fractures. The main form of vitamin D measured is 25-hydroxy-vitamin D (25OHD). While 25OHD assays have improved, they remain a work in progress.

Vitamin D3 levels and insulin resistance in papillary thyroid cancer patients

Both insulin resistance (IR) and vitamin D deficiency (VDD) are found to be associated with many cancer types. In this study, we evaluated the presence of IR and VDD in thyroid cancer patients based on controls. Total 344 papillary thyroid cancer and 116 controls were part of the study. Glucose, insulin, homeostasis model analysis-insulin resistance (HOMA-IR) (control group 2.12 ± 0.9 and patient group 3.6 ± 1.1; p < 0.0001), LDL were significantly high; HOMA-S and vitamin D3 levels (control group 19.11 ± 8 and patient group 17 ± 16; p = 0.004) were significantly low in the patient group. Vitamin D deficiency (64/108 in controls vs 166/235; p = 0.026) and insulin resistance (24/108; 115/235; p < 0.0001) were more frequent in papillary thyroid cancer patients. After regression analysis, tumor diameter showed significant association with log-HOMA-IR (B = 0.315; p = 0.017) and log-vitamin D3 (B = 0.207; p = 0.04). Vitamin D deficiency and insulin resistance frequencies show no difference between micro- and macropapillary thyroid cancers. Receiver operating characteristic curve shows the best cutoff point for tumor diameter showing that the presence of lymph node metastasis was 0.65 cm with 81.2 % sensitivity and 52 % specificity. Best cutoff point for the capsular invasion tumor diameter was 0.75 cm with 83.3 % sensitivity and 60.4 % specificity. No difference between follicular and classical type papillary thyroid carcinomas has been yet discovered. As a result, thyroid cancer patients are more insulin resistant and vitamin D3 deficient. Vitamin D3 levels and HOMA-IR index may affect tumor diameter. Tumor size that is lower than 1 cm (0.65-0.75 cm) may be related with capsular invasion and lymph node involvement.

Vitamin D receptor gene BsmI and FokI polymorphisms in relation to ovarian cancer risk in the Polish population

BACKGROUND

The role of vitamin D receptor (VDR) single-nucleotide polymorphisms (SNPs) in ovarian cancer has been studied in various populations; however, these results are discordant between different ethnicities.

METHOD

Using the polymerase chain reaction-restriction fragment length polymorphism method, we studied the prevalence of the VDR FokI (rs2228570) and BsmI (rs1544410) SNPs in women with ovarian cancer (n=168) and controls (n=182) in a Polish population.

RESULTS

We found a significant contribution of the BsmI SNP Bb+BB-versus-bb dominant inheritance model to ovarian cancer development (p=0.0221, p(corr)=0.0442, odds ratio [OR]=1.648 [95% confidence intervals, CI=1.073-2.532]). However, we did not observe an association of the BsmI SNP BB versus Bb+bb recessive inheritance model in patients (p=0.8059, OR=1.093 [95% CI=0.538-2.218]). Moreover, there was no association of FokI SNPs either in Ff+ff versus FF dominant or ff versus Ff+FF recessive inheritance models with ovarian cancer development (p=0.9924, OR=1.002 [95% CI=0.628-1.599] and p=0.1123, OR=1.542 [95% CI=0.901-2.638], respectively). The p-values of the trend test observed for the VDR BsmI and FokI SNPs in patients with ovarian cancer were p(trend)=0.0613 and p(trend)=0.3655, respectively.

CONCLUSION

Our study indicates that the VDR B gene variant might be a moderate risk factor of ovarian cancer development in the Polish population.