Vitamin D and mortality: meta-analysis of individual participant data from a large consortium of cohort studies from Europe and the United States

Vitamin D deficiency and supplementation in critical illness-the known knowns and known unknowns

The burgeoning literature on vitamin D deficiency and supplementation over the past decade or so has generated a greater understanding of some areas but also an appreciation of the many areas of equipoise. This is particularly relevant in the field of critical care with the heterogeneous patient populations, the severity and duration of illness and the frequency of comorbid conditions.

This review aims to summarise the current knowledge base of vitamin D deficiency within the context of critical illness—“the known knowns”—and also highlight the areas of recognised uncertainty—“the known unknowns”. It acknowledges the fact that there may well be other knowledge gaps of clinical relevance of which we are currently unaware—“the unknown unknowns”.

Study on the association between vitamin D receptor gene fokI (T/C) polymorphisms and the susceptibility to type 2 diabetic kidney disease of Han nationality in south of China

AIMS

To investigate the distribution of vitamin D receptor fokI gene polymorphism in Yunnan Han population, and to explore the relationship between SNP of fokI and type 2 diabetic kidney disease.

METHODS

We included 276 individuals of Han population of Yunnan in this study: 91 type 2 diabetes patients without kidney disease (DM group), their duration of diabetes is more than 10 years, 89 type 2 diabetes patients with diabetic kidney disease (DKD group), their duration of diabetes is less than 10 years and 96 healthy controls (NC group). We compared the concentration of 25 hydroxy vitamin D in different groups and used taqman probe to detect the genotype and allele of fokI, then analysed the relationship between the polymorphisms of fokI and the susceptibility of diabetic kidney disease.

RESULTS

(1) NC group had a significantly higher plasma concentrations of 25 (OH) D than DKD group and DM group (P < 0.01); (2) 25 (OH) D and age, BMI, HbA1c, TG showed a weak negative correlation (P < 0.01); (3) Genotype of fokI showed no differences in DM group and DKD group, same as in DM group and NC group; FF genotype in DKD group is relatively lower than NC group (P < 0.05), and there is no difference in Ff and ff genotype (P > 0.05); In DKD group, f allele was 53.4%, higher than DM group (RR = 1.46, P < 0.05); (4) Logistic regression analysis showed that ff genotype may be a susceptible factor for DKD (P = 0.04, OR = 2.37).

CONCLUSION

FokI Ff genotype accounted for a larger proportion of the Han population in Yunnan, and ff genotype may be a susceptible factor for DKD in Yunnan Han population.

Nutritional Deficiencies and Clinical Correlates in First-Episode Psychosis: A Systematic Review and Meta-analysis

Objective

Diet is increasingly recognized as a potentially modifiable factor influencing the onset and outcomes of psychiatric disorders. Whereas, previous research has shown long-term schizophrenia is associated with various nutritional deficiencies, this meta-analysis aimed to determine the prevalence and extent of nutritional deficits in first-episode psychosis (FEP).

Method

A search of electronic databases conducted in July 2017 identified 28 eligible studies, examining blood levels of 6 vitamins and 10 minerals across 2612 individuals: 1221 individuals with FEP and 1391 control subjects. Meta-analyses compared nutrient levels in FEP to nonpsychiatric controls. Clinical correlates of nutritional status in patient samples were systematically reviewed.

Results

Significantly lower blood levels of folate (N = 6, n = 827, g = -0.624, 95% confidence interval [CI] = -1.176 to -0.072, P = .027) and vitamin D (N = 7, n = 906, g = -1.055, 95% CI = -1.99 to -0.119, P = .027) were found in FEP compared to healthy controls. Synthesis of clinical correlates found both folate and vitamin D held significant inverse relationships with psychiatric symptoms in FEP. There was also limited evidence for serum level reductions of vitamin C (N = 2, n = 96, g = -2.207, 95% CI = -3.71 to -0.71, P = .004). No differences were found for other vitamins or minerals.

Conclusions

Deficits in vitamin D and folate previously observed in long-term schizophrenia appear to exist from illness onset, and are associated with worse symptomology. Further research must examine the direction and nature of these relationships (ie, mediator, moderator, or marker) with clinical status in FEP. Future trials assessing efficacy of nutrient supplementation in FEP samples should consider targeting and stratifying for baseline deficiency.

Variability in genes regulating vitamin D metabolism is associated with vitamin D levels in type 2 diabetes

Mortality rate is increased in type 2 diabetes (T2D). Low vitamin D levels are associated with increased mortality risk in T2D. In the general population, genetic variants affecting vitamin D metabolism (DHCR7 rs12785878, CYP2R1 rs10741657, GC rs4588) have been associated with serum vitamin D. We studied the association of these variants with serum vitamin D in 2163 patients with T2D from the “Sapienza University Mortality and Morbidity Event Rate (SUMMER) study in diabetes”. Measurements of serum vitamin D were centralised. Genotypes were obtained by Eco™ Real-Time PCR. Data were adjusted for gender, age, BMI, HbA1c, T2D therapy and sampling season.

DHCR7 rs12785878 (p = 1 x 10–4) and GC rs4588 (p = 1 x 10–6) but not CYP2R1 rs10741657 (p = 0.31) were significantly associated with vitamin D levels.

One unit of a weighted genotype risk score (GRS) was strongly associated with vitamin D levels (p = 1.1 x 10–11) and insufficiency (<30 ng/ml) (OR, 95%CI = 1.28, 1.16–1.41, p = 1.1 x 10–7).

In conclusion, DHCR7 rs12785878 and GC rs4588, but not CYP2R1 rs10741657, are significantly associated with vitamin D levels. When the 3 variants were considered together as GRS, a strong association with vitamin D levels and vitamin D insufficiency was observed, thus providing robust evidence that genes involved in vitamin D metabolism modulate serum vitamin D in T2D.

Vitamin D insufficiency predicts mortality among older men, but not women: A nationwide retrospective cohort from Thailand

AIM

Previous studies on the association between low vitamin D level and increased mortality mainly came from high-income countries. The primary objective of the present study was to examine the effect of sex on the association between 25-hydroxyvitamin D₂ and D₃ and mortality among community-dwelling older people in Thailand.

METHODS

A cohort of individuals aged ≥60 years from the Thai 4th National Health Examination Survey carried out in 2008 were followed and linked to a vital registry in 2015. Data regarding comorbid diseases, physical activity and serum vitamin D were obtained at the baseline assessment. Factors associated with all-cause mortality were determined using Cox proportional hazards models.

RESULTS

A total of 1268 participants with a median age of 74.0 years (interquartile range 67.0-81.0) were included. The prevalence of vitamin D insufficiency was 24.5% and 43.9% in men and women, respectively. Vitamin D insufficiency was significantly associated with all-cause mortality only among men (adjusted HR 1.77, 95% CI 1.25-2.51), but not women. Analysis of 25-hydroxyvitamin D3 divided into tertiles also showed an association with an adjusted HR of 1.83 (95% CI 1.23-2.72) for the lowest tertile in men. Diabetes was an effect modifier for low serum vitamin D and male sex, with HR 3.34 (95% CI 1.76-6.33, P < 0.001) in diabetic men with vitamin D insufficiency.

CONCLUSIONS

Low serum vitamin D is an independent risk factor for increased mortality in community-dwelling Thai older men. Further randomized controlled study to investigate the benefit of vitamin D3 supplementation in older persons, particularly men, is warranted. Geriatr Gerontol Int 2018; 18: 1585-1590.

Calcitriol combined with calcium chloride causes apoptosis in undifferentiated adipose tissue-derived human mesenchymal stem cells, but this effect decreases during adipogenic differentiation

Calcitriol, the bioactive hormone of vitamin D, is currently linked to several diseases, such as obesity and gain of adipose mass, due to its liposolubility and, consequently, its sequestration by adipocytes. As rates of obesity continue to increase, research on the biology of weight gain should be encouraged. This study evaluated the effects of calcitriol combined with CaCl₂ on adipose tissue-derived human mesenchymal stem cells. We evaluated the cytotoxicity of the combination by MTT assays, in which undifferentiated cells and cells undergoing adipogenic differentiation were tested for 7 and 14 days. The results demonstrated that the combination of calcitriol at the IC₅₀ and CaCl₂ at the IC₂₀ was effective at reducing the viability of mesenchymal stem cells, but with the progression of cell differentiation towards adipocytes, cell resistance to the cytotoxic effects increased. The percentages of dead cells were 88.29, 57.45 and 28.81% for undifferentiated cells and cells exposed to differentiation medium for 7 and 14 days, respectively. Undifferentiated cells were evaluated for apoptosis in response to the same combination using Annexin V assays, and a possible onset of programmed cell death in undifferentiated cells was detected. Additionally, the combination of the compounds altered the membrane permeability of undifferentiated cells by 16 percentage points and induced cell cycle arrest in S phase due to the accumulation of damage. An evaluation of gene expression revealed the overexpression of the GADD45 and ATM genes and the underexpression of the P21, P53, ATR, BCL-2, EIF2 AK3, IGF1R, DNAse-2, ATF, MAP3K4, ENGO-G, CASP3, CASP7 and CASP8 genes. Our results provide valuable insights into the biology of obesity and may contribute to the development of new anti-obesity therapies focusing on the inhibition of adipose tissue mesenchymal stem cell hyperplasia and adipogenic differentiation.

Serum vitamin D deficiency and vitamin D receptor gene polymorphism are associated with increased risk of cardiovascular disease in a Chinese rural population

Several studies have reported a conflicting association between vitamin D deficiency, vitamin D receptor (VDR) polymorphism, and the risk of cardiovascular disease (CVD). We hypothesized that serum 25(OH)D concentrations and single nucleotide polymorphisms (SNPs) of the VDR were associated with and increased risk of CVD. A total of 2378 adults residing in rural parts of China participated in this study. Ultimately, 1142 individuals, including 638 CVD patients and 504 control subjects were included in the study. Logistic regression and restricted cubic spines regression were used to determine the correlation between 25(OH)D and the risk of CVD. Allele frequency and genotype distribution were analyzed between CVD patients and control subjects, and haplotype analysis was used to evaluate the combined effect of VDR SNPs on CVD pathogenesis. In the adjusted model, the odds ratio (95% confidence interval (CI)) of the CVD in the sufficient vitamin D group was 0.76 (0.60-0.96)when compared with the vitamin D deficient group. At 25(OH)D doses of less than 20 ng/mL, there was a dose-response relationship between 25(OH)D and CVD risk. Moreover, the rs3847987 SNP was associated with fasting plasma glucose (FPG) and triglyceride (TG) in CVD patients. In all models, there was a significant association between rs2189480 and CVD, especially in females and those aged ≥55 years. In these groups, rs3847987 SNPs were significantly different, especially in females. Compared with the ACA haplotype, the AAA and CCA haplotypes were associated with increased risk of CVD. In conclusion, our results suggested that serum 25(OH)D levels and VDR SNPs are closely related with CVD pathogenesis.

Effect of vitamin D supplementation on depressive symptoms and psychological wellbeing in healthy adult women: a double-blind randomised controlled clinical trial

Epidemiological evidence has linked low vitamin D status to a range of mood disorders. However, studies examining whether vitamin D supplementation can improve mood-related outcomes in healthy populations are limited. We investigated whether vitamin D supplementation over winter is beneficial for improving mood-related outcomes in healthy women. A total of 152 healthy women (18–40 years) in Dunedin, New Zealand were randomly assigned to receive 50 000 IU (1·25 mg) of oral vitamin D₃ or placebo once per month for 6 months. They completed the Center for Epidemiologic Studies Depression Scale, the anxiety subscale of the Hospital Anxiety and Depression Scale and the Flourishing Scale every month. Additionally, they reported their positive and negative mood each day for three consecutive days every 2 months. Participants provided a blood sample at the beginning and at the end of the study for 25-hydroxyvitamin D₃ analysis. ANCOVA was used to compare the outcome measures between the groups, controlling for baseline. We found no evidence of lower depression (P = 0·339), lower anxiety (P = 0·862), higher flourishing (P = 0·453), higher positive moods (P = 0·518) or lower negative moods (P = 0·538) in the treatment group compared with the control group at follow-up. Mood outcomes over the study period were similar for the two groups. We found no evidence of any beneficial effect of monthly vitamin D₃ supplementation on mood-related outcomes in healthy premenopausal women over the winter period, so recommendations for supplementations are not warranted in this population for mood-related outcomes.

Public health relevance of drug-nutrition interactions

The public health relevance of drug–nutrition interactions is currently highly undervalued and overlooked. This is particularly the case for elderly persons where multi-morbidity and consequently polypharmacy is very common. Vitamins and other micronutrients have central functions in metabolism, and their interactions with drugs may result in clinically relevant physiological impairments but possibly also in positive effects. On 12 April 2016, the University Medical Center Groningen (The Netherlands), as part of its Healthy Ageing program, organized a workshop on the public health relevance of drug–nutrient interactions. In this meeting, experts in the field presented results from recent studies on interactions between pharmaceuticals and nutrients, and discussed the role of nutrition for elderly, focusing on those persons receiving pharmaceutical treatment. This paper summarizes the proceedings of the symposium and provides an outlook for future research needs and public health measures. Since food, pharma and health are closely interconnected domains, awareness is needed in the medical community about the potential relevance of drug–nutrition interactions. Experts and stakeholders should advocate for the integration of drug–nutrition evaluations in the drug development process. Strategies for the individual patients should be developed, by installing drug review protocols, screening for malnutrition and integrating this topic into the general medical advice.

Vitamin D Supplementation, Serum 25(OH)D Concentrations and Cardiovascular Disease Risk Factors: A Systematic Review and Meta-Analysis

Background: Cardiovascular disease (CVD) risk factors are associated with low serum 25 hydroxyvitamin D (25(OH)D) concentrations in observational studies; however, clinical trial findings are inconsistent.

Objective: We assessed the effect of vitamin D supplementation and increased serum 25(OH)D concentrations on CVD risk factors in a systemic review and meta-analysis of randomized controlled trials (RCTs).

Design: MEDLINE, CINAHL, EMBASE, and Google Scholar were searched for RCTs that evaluated vitamin D supplementation and cardiovascular outcomes [blood pressure, parathyroid hormone (PTH), serum high-sensitivity C-reactive protein (hs-CRP), total cholesterol, high and low density lipoprotein (HDL and LDL, respectively), triglycerides, peak wave velocity (PWV) and Augmentation Index (AI)] from 1992 through 2017. Meta-analysis was based on a random-effects model and inverse variance method to calculate standardized mean difference (SMD) as effect sizes, followed by a leave-one-out method for sensitivity analysis. Risk of publication bias was assessed using Cochrane checklist and Begg funnel plots. The systematic review is registered as CRD42015025346.

Results: We identified 2341 studies from which 81 met inclusion criteria. The meta-analysis indicated a significant reduction in systolic blood pressure (SMD = −0.102 ± 0.04 mmHg, 95% confidence interval (CI), −0.20 to −0.03), diastolic blood pressure (SMD = −0.07 ± 0.03 mmHg, 95% CI, −0.14 to −0.006), serum PTH (SMD = −0.66 ± 0.08 ng/L, 95% CI, −0.82 to −0.49), hs-CRP (SMD = −0.20 ± 0.07 mg/L, 95% CI, −0.34 to −0.06), total cholesterol (SMD = −0.15 ± 0.06 mmol/L, 95% CI, −0.25 to −0.04), LDL (SMD = −0.10 ± 0.05 mmol/L, 95% CI, −0.20 to −0.003), triglycerides (SMD = −0.12 ± 0.06 mmol/L, 95% CI, −0.23 to −0.003) and a significant increase in HDL (SMD = 0.09 ± 0.04 mmol/L, 95% CI, 0.00 to 0.17) with vitamin D supplementation. These findings remained significant in sensitivity analyses for blood pressure, lipid profile, serum PTH, and serum hs-CRP. There was no significant effect of vitamin D supplementation on PWV (SMD = −0.20 ± 0.13 m/s, 95% CI, −0.46 to 0.06, p = 0.14) and AI (SMD = −0.09 ± 0.14%, 95% CI, −0.37 to 0.19, p = 0.52) for vitamin D supplemented groups.

Conclusion: These findings suggest that vitamin D supplementation may act to protect against CVD through improving risk factors, including high blood pressure, elevated PTH, dyslipidemia, and inflammation.

Vitamin D, DNA methylation, and breast cancer

BACKGROUND

Vitamin D has anticarcinogenic and immune-related properties and may protect against some diseases, including breast cancer. Vitamin D affects gene transcription and may influence DNA methylation.

METHODS

We studied the relationships between serum vitamin D, DNA methylation, and breast cancer using a case-cohort sample (1070 cases, 1277 in subcohort) of non-Hispanic white women. For our primary analysis, we used robust linear regression to examine the association between serum 25-hydroxyvitamin D (25(OH)D) and methylation within a random sample of the cohort ("subcohort"). We focused on 198 CpGs in or near seven vitamin D-related genes. For these 198 candidate CpG loci, we also examined how multiplicative interactions between methylation and 25(OH)D were associated with breast cancer risk. This was done using Cox proportional hazards models and the full case-cohort sample. We additionally conducted an exploratory epigenome-wide association study (EWAS) of the association between 25(OH)D and DNA methylation in the subcohort.

RESULTS

Of the CpGs in vitamin D-related genes, cg21201924 (RXRA) had the lowest p value for association with 25(OH)D (p = 0.0004). Twenty-two other candidate CpGs were associated with 25(OH)D (p < 0.05; RXRA, NADSYN1/DHCR7, GC, or CYP27B1). We observed an interaction between 25(OH)D and methylation at cg21201924 in relation to breast cancer risk (ratio of hazard ratios = 1.22, 95% confidence interval 1.10-1.34; p = 7 × 10-5), indicating a larger methylation-breast cancer hazard ratio in those with high serum 25(OH)D concentrations. We also observed statistically significant (p < 0.05) interactions for six other RXRA CpGs and CpGs in CYP24A1, CYP27B1, NADSYN1/DHCR7, and VDR. In the EWAS of the subcohort, 25(OH)D was associated (q < 0.05) with methylation at cg24350360 (EPHX1; p = 3.4 × 10-8), cg06177555 (SPN; p = 9.8 × 10-8), and cg13243168 (SMARCD2; p = 2.9 × 10-7).

CONCLUSIONS

25(OH)D concentrations were associated with DNA methylation of CpGs in several vitamin D-related genes, with potential links to immune function-related genes. Methylation of CpGs in vitamin D-related genes may interact with 25(OH)D to affect the risk of breast cancer.

Vitamin D deficiency and risk of cardiovascular diseases: a narrative review

Vitamin D, a fat-soluble prohormone, has wide-ranging roles in the regulation of many physiological processes through their interactions with the vitamin D receptors (VDR). It plays a major role in bones and calcium metabolism. Vitamin D deficiency is not uncommon and it has been associated with many health-related issues, including skeletal and non-skeletal complications. The association of low vitamin D and cardiovascular diseases and risk factors has been explored in both animal and human studies. However, studies and trials on the effect of vitamin D supplementation on cardiovascular risk factors and hypertension are conflicting with inconsistent results. Therefore, large, well-powered randomized controlled trials are warranted. If successful, supplementation with easy and low-cost vitamin D can impact our health positively. Here, we summarized the evidence for the association of vitamin D, cardiovascular diseases and risk factors, including coronary artery diseases, stroke, and hypertension, and mortality, with special consideration to resistant hypertension.

Vitamin D status and epigenetic-based mortality risk score: strong independent and joint prediction of all-cause mortality in a population-based cohort study

Background

Vitamin D deficiency and insufficiency have been established to be strongly associated with increased overall mortality and deaths from specific aging-related diseases. Recently, an epigenetic “mortality risk score” (MS) based on whole blood DNA methylation at the 10 most prominent mortality-related cytosine-phosphate-guanine (CpG) sites has also been found to be highly related to all-cause mortality. This study aimed to explore whether vitamin D status, defined by serum 25-hydroxyvitamin D [25(OH)D] concentrations, is associated with the MS and to what extent both indicators are individually and jointly capable of predicting all-cause mortality in a general population sample of older adults.

Results

The MS was derived from the blood DNA methylation profiles measured by Illumina Human Methylation 450K Beadchip, and serum 25(OH)D concentration was measured among 1467 participants aged 50–75 of the German ESTHER cohort study. There was no association between vitamin D status and the MS at baseline, but both metrics were prominently and independently associated with all-cause mortality during a median follow-up of 15.2 years. The combination of both indicators showed the potential to be a particularly strong prognostic index for all-cause mortality. Participants with vitamin D deficiency (< 30 nmol/L) and high MS (> 5 CpG sites with aberrant methylation) had almost sixfold mortality (hazard ratio 5.79, 95% CI 3.06–10.94) compared with participants with sufficient vitamin D (≥ 50 nmol/L) and a low MS (0–1 CpG site with aberrant methylation).

Conclusions

This study suggests that vitamin D and the MS are strong independent predictors of all-cause mortality in older adults.

Electronic supplementary material

The online version of this article (10.1186/s13148-018-0515-y) contains supplementary material, which is available to authorized users.

Effects of vitamin D supplementation on markers for cardiovascular disease and type 2 diabetes: an individual participant data meta-analysis of randomized controlled trials

Background

Evidence from randomized controlled trials (RCTs) for the causal role of vitamin D on noncommunicable disease outcomes is inconclusive.

Objective

The aim of this study was to investigate whether there are beneficial or harmful effects of cholecalciferol (vitamin D3) supplementation according to subgroups of remeasured serum 25-hydroxyvitamin D [25(OH)D] on cardiovascular and glucometabolic surrogate markers with the use of individual participant data (IPD) meta-analysis of RCTs.

Design

Twelve RCTs (16 wk to 1 y of follow-up) were included. For standardization, 25(OH)D concentrations for all participants (n = 2994) at baseline and postintervention were re-measured in bio-banked serum samples with the use of a certified liquid chromatography-tandem mass spectrometry method traceable to a reference measurement procedure. IPD meta-analyses were performed according to subgroups of remeasured 25(OH)D. Main outcomes were blood pressure and glycated hemoglobin (HbA1c). Secondary outcomes were LDL, HDL, and total cholesterol and triglycerides; parathyroid hormone (PTH); fasting glucose, insulin, and C-peptide; and 2-h glucose. In secondary analyses, other potential effect modifiers were studied.

Results

Remeasurement of 25(OH)D resulted in a lower mean 25(OH)D concentration in 10 of 12 RCTs. Vitamin D supplementation had no effect on the main outcomes of blood pressure and HbA1c. Supplementation resulted in 10-20% lower PTH concentrations, irrespective of the 25(OH)D subgroups. The subgroup analyses according to achieved 25(OH)D concentrations showed a significant decrease in LDL-cholesterol concentrations after vitamin D supplementation in 25(OH)D subgroups with <75, <100, and <125 nmol of -0.10 mmol/L (95% CI: -0.20, -0.00 mmol/L), -0.10 mmol/L (95% CI: -0.18, -0.02 mmol/L), and -0.07 mmol/L (95% CI: -0.14, -0.00 mmol/L), respectively. Patient features that modified the treatment effect could not be identified.

Conclusions

For the main outcomes of blood pressure and HbA1c, the data support no benefit for vitamin D supplementation. For the secondary outcomes, in addition to its effect on PTH, we observed indications for a beneficial effect of vitamin D supplementation only on LDL cholesterol, which warrants further investigation. This trial was registered at www.clinicaltrials.gov as NCT02551835.

Risk factors for vitamin D deficiency in sickle cell disease

Vitamin D deficiency (VDD), 25-OHD levels <20 ng/ml, is prevalent among patients with sickle cell disease (SCD) and is linked to acute and chronic pain and bone fracture in this population. There is limited literature regarding VDD-associated risk factors for SCD. We examined potential clinical and genomic parameters associated with VDD in 335 adults with SCD in a cross-sectional study. VDD was present in 65% of adult SCD patients, and 25-OHD levels independently and positively correlated with older age (P < 0·001) and vitamin D supplementation (P < 0·001). 25-OHD levels were higher in SCD patients over 40 years of age compared to the general African-American population. Both lower 25-OHD levels and increased pain frequency were associated with increased expression of SLC6A5 encoding glycine transporter-2 (GlyT2), a protein involved in neuronal pain pathways. Lower 25-OHD levels were also associated with increased expression of CYP3A4, and with decreased expression of GC (also termed DBP) and VDR, three genes involved in vitamin D metabolism. We conclude that vitamin D supplementation should be an almost universal feature of the care of young adults with SCD, and that further research is warranted into genomic factors that regulate vitamin D metabolism in SCD.

Effect of Vitamin D Serum Levels and GC Gene Polymorphisms in Liver Fibrosis Due to Chronic Hepatitis C

INTRODUCTION AND AIM

Vitamin D has been associated with chronic liver diseases and low vitamin levels may contribute to progression of chronic hepatitis C. The aim of this study was to evaluate the influence of vitamin D serum levels and GC gene polymorphisms in the severity of liver fibrosis in patients with chronic hepatitis C genotype 1.

MATERIAL AND METHODS

Cross-sectional study that enrolled 132 adult patients with chronic hepatitis C genotype 1 attended at the outpatient Clinic of Gastroenterology Division at Hospital de Clínicas de Porto Alegre. At the time of enrollment patients had a blood withdraw for serum 25(OH)D determination and genotypic analysis of rs7041 and rs4588 polymorphisms in GC gene. None/mild fibrosis was considered as METAVIR F0, F1 and F2 and severe fibrosis as METAVIR F3 and F4.

RESULTS

Median 25(OH)D levels in the sample were 19.9 ng/mL (P25-P75: 14.0-29.4). Fifty percent of patients presented vitamin D deficiency (< 20 ng/mL). In stepwise multiple linear regression the variables associated with 25(OH)D levels were blood withdrawn in Winter/spring season, the haplotypes AT/AT + AG/AT of rs7041 and rs4588 and female sex. For evaluation of severe fibrosis, variables associated in logistic regression were age, vitamin D severe deficiency (< 10 ng/mL), glucose levels, BMI and platelets count.

CONCLUSIONS

Vitamin D levels are associated with severity of liver fibrosis in chronic hepatitis C genotype 1 patients. Although the rs7041 and rs4588 GC polymorphisms are strong predictors of vitamin D levels, they do not play a direct role in liver fibrosis.

Emerging Evidence of Thresholds for Beneficial Effects from Vitamin D Supplementation

Publications from clinical trials of vitamin D supplementation have increased substantially over the last 15 years. Yet, despite the growing number of randomized controlled trials, meta-analyses of these studies have drawn inconsistent conclusions. Many meta-analyses assume that vitamin D is a pharmacological agent, and give scant consideration of it being a nutrient. This limits their potential to detect beneficial effects in participants with vitamin D deficiency. An increasing body of evidence from both observational studies and clinical trials supports the presence of thresholds in vitamin D status below which disease risk increases and vitamin supplementation has beneficial effects. Future supplementation trials which seek to replicate these findings should recruit sufficient numbers of participants with low vitamin D levels, and not give low-dose vitamin D to the placebo group. If the presence of vitamin D thresholds for beneficial effects is confirmed, this would strengthen the need for vitamin D fortification of foods.

Cardiometabolic risk factors, physical activity and psychiatric status in patients in long-term psychiatric inpatient departments

PURPOSE

Cardiovascular diseases are a major cause for the markedly reduced life expectancy in people with severe mental illness (SMI). Hospital departments should provide adequate prevention of cardiometabolic risk by optimizing prevention and treatment. Characteristics of cardiometabolic risk factors in inpatients are still not well known. We aimed to describe the status of cardiometabolic risk factors in inpatients with SMI and identify associations with psychiatric status and treatment.

METHODS

A cross sectional descriptive study of inpatients with SMI from long term psychosis treatment wards in South Eastern Norway was performed. Comprehensive assessments of cardiometabolic risk factors, physical activity, lifestyle habits, symptoms, life satisfaction and treatment were made. Associations and potential prognostic factors were analyzed using linear and logistic regressions.

RESULTS

A total of 83 patients were included in the study, but many individual datasets were incomplete. Over half of the subjects had unhealthy eating habits. Obesity (class 1-3) was found in 44%, 23% had elevated fasting triglycerides, 26% had elevated blood pressure and 78% smoked daily. Low levels of physical activity were significantly associated with higher levels of depression (p = .007). A nominal increase in cardiometabolic risk factors was found for olanzapine and clozapine users.

CONCLUSION

Inpatients in long term psychosis treatment wards have alarmingly high cardiometabolic risk. Level of physical activity was associated with both psychiatric and somatic health. Focus on lifestyle and somatic health should be an integral part of the treatment for hospitalized SMI patients.

Association of plasma vitamin D status with lifestyle patterns and ambulatory blood pressure monitoring parameters in patients with type 2 diabetes and hypertension

AIMS

To evaluate nutritional and metabolic parameters associated with vitamin D status and blood pressure (BP) in type 2 diabetes and hypertensive patients.

METHODS

BP evaluated by office and 24-h ambulatory BP monitoring (ABPM). Physical activity was evaluated by daily step count, body composition by DXA, and diet by a food frequency questionnaire.

RESULTS

116 patients were evaluated and median 25-hydroxyvitamin D level was 21 (16-27) ng/ml; 43% deficient (<20 ng/ml). Vitamin D deficiency was associated with higher systolic ABPM (136 ± 10 vs. 130 ± 13 mmHg; P = 0.01) and daytime ABPM (138 ± 11 vs. 133 ± 13 mmHg; P = 0.02), lower step counts (4400 [2700-6600] vs. 6400 [4700-8100] steps/day), lower urinary calcium (47 [32-141] vs. 89 [68-152] mEq), and higher fat mass (31 ± 8 vs. 27 ± 6.5 kg). Milk intake (37 vs. 64%; P = 0.009) and fish (31 vs. 69%; P < 0.001) were lower in deficients. On multivariate analysis, adjusted for fat mass and colder seasons, <5000 steps/day (OR = 3.30; 95%CI 1.34-8.12), no milk/fish intake (OR = 6.56; 95%CI 2.52-17.17), and both (OR = 7.24; 95%CI 2.19-23.90) remained associated with vitamin D deficiency.

CONCLUSIONS

Vitamin D deficiency was highly prevalent in patients with hypertension and type 2 diabetes and associated with higher systolic ABPM (daytime and 24-h), less physical activity, and no milk or fish intake.

Vitamin D and Cancer Risk and Mortality: State of the Science, Gaps, and Challenges

There has been substantial enthusiasm recently regarding the potential role of vitamin D in the primary and secondary prevention of cancer. Laboratory studies demonstrate a range of anticarcinogenic effects for vitamin D compounds, but human studies have yielded little consistent evidence supporting a protective association. Higher circulating levels of vitamin D (i.e., 25-hydroxyvitamin D or 25(OH)D) appear to be associated with reduced risk of colorectal and bladder malignancies, but higher risk of prostate and possibly pancreatic cancers, with no clear association for most other organ sites examined. Despite there being no official institutional recommendations regarding the use of vitamin D supplements for cancer prevention, screenings for vitamin D deficiency and vitamin D supplement use have increased substantially over the past decade. These widespread practices demonstrate that population sociobehavioral changes are often adopted before scientifically well-informed policies and recommendations are available. This review critically examines the currently available epidemiologic literature regarding the associations between circulating 25(OH)D, vitamin D supplementation, and vitamin D-related genetic variation and cancer risk and mortality, with a particular emphasis on prospective studies. We identify several important gaps in our scientific knowledge that should be addressed in order to provide sufficient reproducible data to inform evidence-based recommendations related to optimal 25(OH)D concentrations (and any role for vitamin D supplementation) for the primary and secondary prevention of cancer. With few exceptions, such recommendations cannot be made at this time.

Vitamin D Deficiency and Supplementation in Cardiovascular Disorders

Cardiovascular disease (CVD) is the leading cause of death in developed countries. Similarly, the frequency of vitamin D deficiency is increasing, and a number of epidemiologic and clinical studies have suggested that there is an increased risk of CVD among people with depletion of this vitamin. This has raised much interest in the potential pathogenic and therapeutic role of vitamin D in CVD. However, randomized trials and meta-analyses have not shown a clear benefit of vitamin D supplementation with respect to cardiovascular events. Herein, we provide a comprehensive review of the most relevant evidence to date regarding vitamin D deficiency and supplementation, and their respective impact on CVD prevention and treatment.

Vitamin D deficiency in relation to the poor functional outcomes in nondiabetic patients with ischemic stroke

To assess the hypothesis that vitamin D, reflected by 25-hydroxyvitamin D (25(OH) D) would be associated with higher risk of poor functional outcomes amongst nondiabetic stroke patients. The present study was conducted in Nanchang, China. Serum concentration of 25(OH) D and National Institutes of Health Stroke Scale (NIHSS) were measured at the time of admission. Functional outcome was measured by modified Rankin scale (mRS) at 1 year after admission. Multivariate analyses were performed using logistic regression models. The cut point of 25(OH) D level for vitamin D deficiency was 20 ng/ml. In the present study, 266 nondiabetic subjects with stroke were included; 149 out of the 266 patients were defined as vitamin D deficiency (56%). The poor outcome distribution across the 25(OH) D quartiles ranged between 64% (first quartile) and 13% (fourth quartile). In those 149 patients with vitamin D deficiency, 75 patients were defined as poor functional outcomes, giving a prevalence rate of 50% (95% confidence interval (CI): 42–58%). In multivariate analysis models, for vitamin D deficiency, the adjusted risk of poor functional outcomes and mortality increased by 220% (odds ratio (OR): 3.2; 95% CI: 1.7–4.2, P<0.001) and 290% (OR: 3.9; 95% CI: 2.1–5.8, P<0.001), respectively. Vitamin D deficiency is associated with an increased risk of poor functional outcome events in Chinese nondiabetic stroke individuals.

Body mass index represents a good predictor of vitamin D status in women independently from age

BACKGROUND & AIMS

Vitamin D is a pleiotropic hormone targeting several tissues and is involved in basic homeostatic processes, including bone mineralization, immune response and muscle strength. Although hypovitaminosis D is common in Europe and North America, representing a risk factor for several chronic diseases, the contribution of factors other than sun exposure is largely underestimated.

METHODS

In our study, we retrospectively collected data from medical records of women with age between 19 and 80 screened in Central Italy (42°N) for increased risk of metabolic syndrome. Vitamin D status was evaluated by serum 25-hydroxyvitamin D (25(OH)D) measurement and the association among vitamin D status and anthropometric and clinic variables was tested by multivariate logistic analysis.

RESULTS

More than 80% of women presented serum 25(OH)D concentration lower than 30 ng/mL (75 nM), with the majority of values falling between 10 and 20 ng/mL. 25(OH)D concentration was dependent on season, with the highest 25(OH)D mean value measured in September and the lowest mean value in March. Among different clinical characteristics, body mass index (BMI) demonstrated the highest significant inverse correlation with serum 25(OH)D values, independently from season and age. Serum 25(OH)D values demonstrated a seasonal-directed sinusoidal trend and they raised during spring/summer in a similar manner in both obese and non-obese women. However, the obese group had lower mean values of vitamin D respect to overweight and to normal weight groups in both winter and summer, reaching frequently the status of vitamin D deficiency (<10 ng/mL).

CONCLUSIONS

In conclusion, at our latitude, seasonal UV irradiance availability determines an obligate sinusoidal trend in vitamin D status. However, body mass is able to reduce proportionally circulating vitamin D over calendar months determining vitamin D deficiency. These results suggest taking in particular account BMI in clinical management of vitamin D status in overweight and obese women.

1,25-Dihydroxy vitamin D prevents tumorigenesis by inhibiting oxidative stress and inducing tumor cellular senescence in mice

Human epidemiological studies suggest that 1,25(OH)₂ D₃ deficiency might increase cancer incidence, but no spontaneous tumors have been reported in mice lacking 1,25(OH)₂ D₃ or deficient in its receptor. In our study, we detected, for the first time, diverse types of spontaneous tumors in l,25(OH)₂ D₃ deficient mice more than 1 year of age. This was associated with increased oxidative stress, cellular senescence and senescence-associated secretory phenotype molecules, such as hepatocyte growth factor, mediated via its receptor c-Met. Furthermore, 1,25(OH)₂ D₃ prevented spontaneous tumor development. We also demonstrated that l,25(OH)₂ D₃ deficiency accelerates allograft tumor initiation and growth by increasing oxidative stress and DNA damage, activating oncogenes, inactivating tumor suppressor genes, stimulating malignant cell proliferation and inhibiting their senescence; in contrast, supplementation with exogenous l,25(OH)₂ D₃ or antioxidant, or knock-down of the Bmi1 or c-Met oncogene, largely rescued the phenotypes of allograft tumors. Results from our study suggest that 1,25(OH)₂ D₃ deficiency enhances tumorigenesis by increasing malignant cell oxidative stress and DNA damage, stimulating microenvironmental cell senescence and a senescence-associated secretory phenotype, and activating oncogenes and inactivating tumor suppressor genes, thus increasing malignant cell proliferation. Our study provides direct evidence supporting the role of vitamin D deficiency in increasing cancer incidence. Conversely, 1,25(OH)₂ D₃ prevented spontaneous tumor development, suggesting that this inhibitory effect prevents the initiation and progression of tumorigenesis, thus provides a mechanistic basis for 1,25(OH)₂ D₃ to prevent tumorigenesis in an aging organism.

Plasma 25-Hydroxyvitamin D and Mortality in Patients With Suspected Stable Angina Pectoris

CONTEXT AND OBJECTIVE

Vitamin D status may affect cardiovascular disease (CVD) development and survival. We studied the relationship between concentrations of the circulating biomarker 25-hydroxyvitamin D (25OHD) and all-cause and cardiovascular mortality risk.

DESIGN, SETTING, PARTICIPANTS, AND MAIN OUTCOME MEASURES

25OHD, the sum of 25-hydroxyvitamin D3 and 25-hydroxyvitamin D2, was analyzed in plasma samples from 4114 white patients suspected of having stable angina pectoris and was adjusted for seasonal variation. Hazard ratios (HRs) for all-cause and cardiovascular mortality were estimated by using multivariable Cox models with 25OHD as the main exposure variable, with adjustment for study site, age, sex, smoking, body mass index, estimated glomerular filtration rate, and systolic blood pressure.

RESULTS

A total of 895 (21.8%) deaths, including 407 (9.9%) from CVD causes, occurred during a mean ± standard deviation follow-up of 11.9 ± 3.0 years. Compared with the first 25OHD quartile, HRs in the second, third, and fourth quartiles were 0.64 [95% confidence interval (CI), 0.54 to 0.77], 0.56 (95% CI, 0.46 to 0.67), and 0.56 (95% CI, 0.46 to 0.67) for all-cause mortality and 0.70 (95% CI, 0.53 to 0.91), 0.60 (95% CI, 0.45 to 0.79), and 0.57 (95% CI, 0.43 to 0.75) for cardiovascular mortality, respectively. Threshold analysis demonstrated increased all-cause and CVD mortality in patients with 25OHD concentrations below ∼42.5 nmol/L. Moreover, analysis suggested increased all-cause mortality at concentrations >100 nmol/L.

CONCLUSION

Plasma 25OHD concentrations were inversely associated with cardiovascular mortality and nonlinearly (U-shaped) associated with all-cause mortality.

Vitamin D, Calcium, and Cardiovascular Disease: A"D"vantageous or "D"etrimental? An Era of Uncertainty

While the function of vitamin D in regulating calcium homeostasis is well established, there has been growing interest in its role in the prevention of numerous chronic diseases, including cardiovascular disease (CVD). There is mounting epidemiological evidence suggesting that vitamin D deficiency is linked to increased CVD risk. However, the results of previous vitamin D supplementation trials have yielded mixed results in regards to cardiovascular health, and the results of ongoing large-scale randomized controlled trials are not yet available. Further complicating the issue, calcium supplementation, which is often prescribed concurrently with vitamin D, has been associated with increased CVD risk in some (but not all) studies. Thus, it is currently unclear whether vitamin D supplements, particularly for those that are deficient, can help prevent the development of CVD. In addition, there has not been uniform consensus regarding the threshold of 25-hydroxyvitamin D levels that constitutes "sufficiency" across organizational guidelines. This review will provide an update on the most recent evidence regarding the effects of vitamin D and calcium supplements on CVD clinical outcomes, summarize ongoing vitamin D trials, and discuss the current but remarkably disparate recommendations regarding vitamin D deficiency screening and supplementation.

Vitamin D Receptor Expression in Dogs

Background

There is growing evidence linking low blood vitamin D concentration to numerous diseases in people and in dogs. Vitamin D influences cellular function by signaling through the vitamin D receptor (VDR). Little is known about which non‐skeletal tissues express the VDR or how inflammation influences its expression in the dog.

Objectives

To define which non‐skeletal canine tissues express the VDR and to investigate expression in inflamed small intestine.

Animals

Thirteen non‐skeletal tissues were collected prospectively from 6 control dogs. Thirty‐five dogs diagnosed with a chronic enteropathy (CE) and 24 control dogs were prospectively enrolled and duodenal biopsies were evaluated for VDR expression.

Methods

Prospective; blinded assessment of canine intestinal VDR. Dogs with CE were included once other identifiable causes of intestinal disease were excluded. Age matched controls were included with no intestinal clinical signs. VDR expression was assessed immunohistochemically in all samples, using a Rat IgG VDR monoclonal antibody. Quantitative real‐time polymerase chain reaction (qPCR) was also used for duodenal biopsies.

Results

VDR expression as assessed by immunohistochemistry (IHC) was highest in the kidney, duodenum, skin, ileum and spleen, and weak in the colon, heart, lymph node, liver, lung, and ovary. Gastric and testicular tissue did not express the VDR. There was no statistical difference in duodenal VDR expression between the 24 healthy dogs and 34 dogs with CE when quantified by either qPCR (P = 0.87) or IHC (P = 0.099).

Conclusions and Clinical Importance

The lack of down regulation of VDR expression in inflamed intestine contrasts with previous studies in humans. Our findings support future studies to investigate whether vitamin D and its analogues can be used to modulate intestinal inflammation in the dog.

Vitamin D Levels Do Not Predict Risk of Metatarsal Fractures

INTRODUCTION

In the literature, there is conflicting data regarding the relationship between vitamin D and fractures. Reports on the effects of vitamin D levels on pathologies of the foot and ankle are limited. The purpose of this study is to assess the prevalence of vitamin D insufficiency in patients who have sustained low-energy metatarsal fractures compared to foot or ankle sprains without osseous involvement.

METHODS

Between May 2012 and August 2014, vitamin D levels and demographic data were collected prospectively in a total of 99 patients; 71 with metatarsal fractures and 28 with sprains, both from a low-energy mechanism of injury. Data between the metatarsal fracture group and sprain group were compared through univariate and multivariate analyses.

RESULTS

Mean vitamin D in the fracture group was 26.9 ng/mL (range = 78.0-4.3), and in the sprain group it was 27.1 ng/mL (range = 64.1-8.3; P = .93). Vitamin D insufficiency (<30 ng/mL) was present in 47 (66%) of fracture patients and 20 (71%) of sprain patients ( P = .81).

CONCLUSION

A high incidence of hypovitaminosis D was seen in all foot and ankle patients. There was no difference in mean vitamin D level or incidence of vitamin D insufficiency between patients with metatarsal fractures or sprains resulting from similar low-energy mechanisms.

LEVELS OF EVIDENCE

Level III: Prospective, case-control study.

Serum 25-hydroxyvitamin D as a predictor of mortality and cardiovascular events: A 20-year study of a community-based cohort

OBJECTIVE

Prospective studies, mostly from Europe and North America, suggest that serum 25-hydroxyvitamin D (25(OH)D) is inversely associated with mortality and cardiovascular disease (CVD) risk. Data from other regions are limited, and threshold levels for adverse cardiovascular outcomes are uncertain. We examined serum 25(OH)D as a predictor of total mortality and cardiovascular outcomes in an Australian cohort.

DESIGN

A 20-year, community-based cohort study.

PATIENTS

Participants in the 1994/1995 Busselton Health Survey (n = 3946, baseline age 25-84 years).

MEASUREMENTS

Baseline serum 25(OH)D and mortality and cardiovascular outcomes to 2014 obtained by record linkage.

RESULTS

The mean serum 25(OH)D concentration was 60.6 ± 18.0 nmol/L. During 20-year follow-up (excluding the first 2 years), 889 participants died (including 363 from CVD) and 944 experienced a CVD event (including 242 with heart failure). In the full cohort, controlling for Framingham risk score variables, higher baseline 25(OH)D was associated with significantly reduced all-cause mortality (adjusted HR 0.83 per SD increment of 25(OH)D, 95% CI 0.77-0.90), CVD death (HR 0.85, 95% CI 0.74-0.96) and heart failure (HR 0.81, 95% CI 0.69-0.94), but not CVD events (HR 0.99, 0.92-1.07). In restricted cubic spline regression models, serum 25(OH)D below 65 and 55 nmol/L was associated with higher total mortality and higher CVD mortality/heart failure, respectively. In participants without CVD at baseline (n = 3220), results were similar, but hazard ratios were attenuated and associations with CVD mortality no longer significant.

CONCLUSIONS

In an Australian community-based cohort, baseline vitamin D levels below 55-65 nmol/L are predictive of all-cause mortality, CVD death and heart failure.

Is there a role for vitamin D in supporting cognitive function as we age?

Globally, an estimated 46 million people are currently living with dementia and this figure is projected to increase 3-fold by 2050, highlighting this major public health concern and its substantial associated healthcare costs. With pharmacological treatment yet to reach fruition, the emphasis on evidence-based preventative lifestyle strategies is becoming increasingly important and several modifiable lifestyle factors have been identified that may preserve cognitive health. These include good cardiovascular health, physical activity, low alcohol intake, smoking and a healthy diet, with growing interest in vitamin D. The aim of the present paper is to review the evidence supporting the potential roles of vitamin D in ageing and cognitive health in community-dwelling older adults. Furthermore, to describe the utility and challenges of cognitive assessments and outcomes when investigating vitamin D in this context. Evidence indicates that serum 25-hydroxyvitamin D (25(OH)D) may impact brain health. There is a biological plausibility from animal models that vitamin D may influence neurodegenerative disorders, through several mechanisms. Epidemiological evidence supports associations between low serum 25(OH)D concentrations and poorer cognitive performance in community-dwelling older populations, although an optimal 25(OH)D level for cognitive health could not be determined. The effect of raising 25(OH)D concentrations on cognitive function remains unclear, as there is a paucity of interventional evidence. At a minimum, it seems prudent to aim to prevent vitamin D deficiency in older adults, with other known common protective lifestyle factors, as a viable component of brain health strategies.

The interaction between vitamin D receptor polymorphisms and sun exposure around time of diagnosis influences melanoma survival

Evidence on the relationship between the vitamin D pathway and outcomes in melanoma is growing, although it is not always clear. We investigated the impact of measured levels of sun exposure at diagnosis on associations of vitamin D receptor gene (VDR) polymorphisms and melanoma death in 3336 incident primary melanoma cases. Interactions between six SNPs and a common 3'-end haplotype were significant (p < .05). These SNPs, and a haplotype, had a statistically significant association with survival among subjects exposed to high UVB in multivariable regression models and exerted their effect in the opposite direction among those with low UVB. SNPs rs1544410/BsmI and rs731236/TaqI remained significant after adjustment for multiple testing. These results suggest that the association between VDR and melanoma-specific survival is modified by sun exposure around diagnosis, and require validation in an independent study. Whether the observed effects are dependent or independent of vitamin D activation remains to be determined.

Association Between Two Common Polymorphisms of Vitamin D Binding Protein and the Risk of Coronary Artery Disease: A Case-control Study

Background

Coronary Artery Disease (CAD) is one of the most widespread non-communicable diseases. Vitamin Dbinding protein (VDBP) and its genetic poly morphisms have been highlighted as the susceptible components for CAD. The aim of the present study was to examine the association of VDBP single nucleotide poly morphisms (SNPs) - rs7041 and rs4588 - with CAD susceptibility among the Iranian population.

Methods

A total of 143 men with CAD and 145 healthy age-sex matched controls underwent genotyping for the - rs7041 and rs4588 polymorphisms using the polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) method. Serum level of 25(OH)D was assayed using microplate colorimetric enzyme immunoassay.

Results

We found a significant association between GG genotype (rs7041) and CAD (p=0.02, OR=0.537 95% CI =0.306-0.944). Regarding rs4588 polymorphism, a significant difference was observed in which the CA genotype (p=0.00032, OR=2.578, 95% CI=1.579-4.208) and allele A (P=0.028, OR=1.491, 95% CI=1.043-2.132) were significantly higher in CAD patients compared to controls. In spite of lower serum levels of 25(OH)D in CAD patients, we found no significant association between these SNPs and Vitamin D serum concentrations.

Conclusion

We concluded that VDBP polymorphisms affect the susceptibility to CAD in Iranian men. Therefore, further studies are required to clarify the association of VDBP phenotypes and its serum levels with CAD.

Effects of Vitamin D on Blood Pressure, Arterial Stiffness, and Cardiac Function in Older People After 1 Year: BEST-D (Biochemical Efficacy and Safety Trial of Vitamin D)

BACKGROUND

The relevance of vitamin D for prevention of cardiovascular disease is uncertain. The BEST-D (Biochemical Efficacy and Safety Trial of vitamin D) trial previously reported effects of vitamin D on plasma markers of vitamin D status, and the present report describes the effects on blood pressure, heart rate, arterial stiffness, and cardiac function.

METHODS AND RESULTS

This was a randomized, double-blind, placebo-controlled trial of 305 older people living in United Kingdom, who were allocated vitamin D 4000 IU (100 μg), vitamin D 2000 IU (50 μg), or placebo daily. Primary outcomes were plasma concentrations of 25-hydroxy-vitamin D and secondary outcomes were blood pressure, heart rate, and arterial stiffness in all participants at 6 and 12 months, plasma N-terminal prohormone of brain natriuretic peptide levels in all participants at 12 months, and echocardiographic measures of cardiac function in a randomly selected subset (n=177) at 12 months. Mean (SE) plasma 25-hydroxy-vitamin D concentrations were 50 (SE 2) nmol/L at baseline and increased to 137 (2.4), 102 (2.4), and 53 (2.4) nmol/L after 12 months in those allocated 4000 IU/d, 2000 IU/d of vitamin D, or placebo, respectively. Allocation to vitamin D had no significant effect on mean levels of blood pressure, heart rate, or arterial stiffness at either 6 or 12 months, nor on any echocardiographic measures of cardiac function, or plasma N-terminal prohormone of brain natriuretic peptide concentration at 12 months.

CONCLUSIONS

The absence of any significant effect of vitamin D on blood pressure, arterial stiffness, or cardiac function suggests that any beneficial effects of vitamin D on cardiovascular disease are unlikely to be mediated through these mechanisms.

CLINICAL TRIAL REGISTRATION

URL: https://www.clinicaltrialsregister.eu/ctr-search/search. Unique identifier: EudraCT number: 2011-005763-24a.

Vitamin D, leptin and impact on immune response to seasonal influenza A/H1N1 vaccine in older persons

BACKGROUND

Influenza-related complications are highest in the elderly. Vaccine efficacy is lower due to immunosenescence. Vitamin D's immunomodulatory role was studied in the context of vaccine response.

METHODS

We evaluated the effect of baseline 25-(OH) D on vaccine-induced immunological response in a cohort of 159 healthy subjects ages 50-74 in Rochester, MN, who received one dose of seasonal trivalent 2010-2011 influenza vaccine, containing A/California/H1N1- like virus. We examined correlations between 25-(OH) D, leptin, and leptin-related gene SNPs to understand the role of leptin and vitamin D's effects.

RESULTS

The median (IQR) baseline for total 25-(OH) D was 44.4 ng/mL (36.6-52.2 ng/mL). No correlation was observed with age. No correlation between 25-(OH) D levels and humoral immune outcomes existed at any timepoint. There was a weak positive correlation between 25-(OH) D levels and change (Day 75-Day 0) in influenza-specific granzyme-B response (r=0.16, p=0.04). We found significant associations between 3 SNPs in the PPARG gene and 25-(OH) D levels (rs1151996, p=0.01; rs1175540, p= 0.02; rs1175544, p=0.03).

CONCLUSION

Several SNPs in the PPARG gene were significantly associated with baseline 25-(OH) D levels. Understanding the functional and mechanistic relationships between vitamin D and influenza vaccine-induced immunity could assist in directing new influenza vaccine design.

Changes in the human transcriptome upon vitamin D supplementation

Vitamin D is hydroxylated in the liver and kidneys to its active form, which can bind to the vitamin D receptor (VDR). The VDR is present in a wide variety of different cells types and tissues and acts as a transcription factor. Although activation of the VDR is estimated to regulate expression of up to 5% of the human genome, our study is the first analysing gene expression after supplementation in more than 10 subjects. Subjects of a randomized controlled trial (RCT) received either vitamin D₃ (n=47) in a weekly dose of 20,000 IU or placebo (n=47) for a period of three to five years. For this study, blood samples for preparation of RNA were drawn from the subjects and mRNA gene expression in blood was determined using microarray analysis. The two study groups were similar regarding gender, age, BMI and duration of supplementation, whereas the mean serum 25-hydroxyvitamin D (25(OH)D) level as expected was significantly higher in the vitamin D group (119 versus 63nmol/L). When analysing all subjects, nearly no significant differences in gene expression between the two groups were found. However, when analysing men and women separately, significant effects on gene expression were observed for women. Furthermore, when only including subjects with the highest and lowest serum 25(OH)D levels, additional vitamin D regulated genes were disclosed. Thus, a total of 99 genes (p≤0.05, log2 fold change ≥|0.2|) were found to be regulated, of which 72 have not been published before as influenced by vitamin D. These genes were particularly involved in the interleukin signaling pathway, oxidative stress response, apoptosis signaling pathway and gonadotropin releasing hormone receptor pathway. Thus, our results open the possibility for many future studies.

Associations of fibroblast growth factor 23, vitamin D and parathyroid hormone with 5-year outcomes in a prospective primary care cohort of people with chronic kidney disease stage 3

OBJECTIVES

Vitamin D deficiency, elevated fibroblast growth factor 23 (FGF23) and elevated parathyroid hormone (PTH) have each been associated with increased mortality in people with chronic kidney disease (CKD). Previous studies have focused on the effects of FGF23 in relatively advanced CKD. This study aims to assess whether FGF23 is similarly a risk factor in people with early CKD, and how this risk compares to that associated with vitamin D deficiency or elevated PTH.

DESIGN

Prospective cohort study.

SETTING

Thirty-two primary care practices.

PARTICIPANTS

One thousand six hundred and sixty-four people who met Kidney Disease: Improving Global Outcomes (KDIGO) definitions for CKD stage 3 (two measurements of estimated glomerular filtration rate (eGFR) between 30 and 60 mL/min/1.73 m² at least 90 days apart) prior to study recruitment.

OUTCOME MEASURES

All-cause mortality over the period of study follow-up and progression of CKD defined as a 25% fall in eGFR and a drop in GFR category, or an increase in albuminuria category.

RESULTS

Two hundred and eighty-nine participants died during the follow-up period. Vitamin D deficiency (HR 1.62, 95% CI 1.01 to 2.58) and elevated PTH (HR 1.42, 95% CI 1.09 to 1.84) were independently associated with all-cause mortality. FGF23 was associated with all-cause mortality in univariable but not multivariable analysis. Fully adjusted multivariable models of CKD progression showed no association with FGF23, vitamin D status or PTH.

CONCLUSIONS

In this cohort of predominantly older people with CKD stage 3 and low risk of progression, vitamin D deficiency and elevated PTH were independent risk factors for all-cause mortality but elevated FGF23 was not. While FGF23 may have a role as a risk marker in high-risk populations managed in secondary care, our data suggest that it may not be as important in CKD stage 3, managed in primary care.

TRIAL REGISTRATION NUMBER

National Institute for Health Research Clinical Research Portfolio Study Number 6632.

Vitamin D intake and risk of CVD and all-cause mortality: evidence from the Caerphilly Prospective Cohort Study

Objective

Prospective data on the associations between vitamin D intake and risk of CVD and all-cause mortality are limited and inconclusive. The aim of the present study was to investigate the associations between vitamin D intake and CVD risk and all-cause mortality in the Caerphilly Prospective Cohort Study.

Design

The associations of vitamin D intake with CVD risk markers were examined cross-sectionally at baseline and longitudinally at 5-year, 10-year and >20-year follow-ups. In addition, the predictive value of vitamin D intake for CVD events and all-cause mortality after >20 years of follow-up was examined. Logistic regression and general linear regression were used for data analysis.

Setting

Participants in the UK.

Subjects

Men (n452) who were free from CVD and type 2 diabetes at recruitment.

Results

Higher vitamin D intake was associated with increased HDL cholesterol (P=0·003) and pulse pressure (P=0·04) and decreased total cholesterol:HDL cholesterol (P=0·008) cross-sectionally at baseline, but the associations were lost during follow-up. Furthermore, higher vitamin D intake was associated with decreased concentration of plasma TAG at baseline (P=0·01) and at the 5-year (P=0·01), but not the 10-year examination. After >20 years of follow-up, vitamin D was not associated with stroke (n72), myocardial infarctions (n142), heart failure (n43) or all-cause mortality (n281), but was positively associated with increased diastolic blood pressure (P=0·03).

Conclusions

The study supports associations of higher vitamin D intake with lower fasting plasma TAG and higher diastolic blood pressure.

The Association between Vitamin D Insufficiency and Nonalcoholic Fatty Liver Disease: A Population-Based Study

Previous studies have shown inconsistent results regarding the association between vitamin D insufficiency and nonalcoholic fatty liver disease (NAFLD). We attempted to demonstrate this relationship using population-based data. Vitamin D insufficiency was defined as a 25(OH)D level ≤20 ng/mL. Hepatic steatosis index was calculated to define NAFLD. Significant fibrosis was assessed using Body mass index, AST/ALT Ratio, Diabetes (BARD) score. Logistic regression analyses were performed to determine the relationship between vitamin D insufficiency and NAFLD. Among 1812 participants, 409 (22.6%) had NAFLD. Patients with nonalcoholic fatty liver disease were more likely to be male (56.7%), had higher body mass index (28.1 kg/m²), and had more metabolic syndrome (57.2%). The proportion of vitamin D insufficiency did not differ between NAFLD and non-NAFLD (77.5% vs. 77.4%). Logistic regression analyses showed that BMI, diabetes, and triglyceride level were significantly associated with NAFLD, whereas vitamin D insufficiency was not related. Subgroup analyses involving non-obese participants, male participants, and participants without metabolic syndrome showed similar results. The BARD score and the proportion of significant fibrosis by BARD score did not differ according to vitamin D status. Vitamin D insufficiency was not associated with the presence of NAFLD as assessed by validated noninvasive prediction models.

Circulating 25-Hydroxy Vitamin D Relative to Vitamin D Receptor Polymorphism after Vitamin D3 Supplementation in Breast Cancer Women: A Randomized, Double-Blind Controlled Clinical Trial

Objective: The influence of vitamin D receptor (VDR) genetic variation on serum 25-hydroxyvitamin D levels [25(OH)D] after vitamin D3 supplementation remains unclear. We aimed to investigate changes of 25(OH)D in a randomized, double-blind, placebo-controlled clinical trial, according to VDR genotype, after provision of vitamin D3 to breast cancer cases for a 2-month period. Methods: Participants were assigned to two treatment arms: placebo (n = 28) and vitamin D3 supplementation (n =28). The supplementation group received 50,000 IU of vitamin D every week for 2 months. Blood samples were collected at baseline and after intervention to measure serum 25(OH)D3. Genotypes were assessed for FokI, BsmI, ApaI, and TaqI polymorphisms. Results: After eight weeks supplementation, the intervention group showed a significant increase in the serum concentration of 25 (OH)D3 (28±2.6 to 39±3.5; p=0.004). Subjects were then classified into twelve subgroups according to different VDR genotypes. Subjects with ff/Ff, TT/Tt, and Bb genotypes had significantly higher increases in serum 25(OH)D compared to those with FF, tt, and BB/bb genotypes post-intervention. Serum vitamin D3 levels with the AA genotype were lower than with aa/ Aa. No differences were found among other subgroups. Conclusion: Vitamin D3 supplementation increases serum 25(OH)D in women with breast cancer. Serum vitamin D3 in TT/Tt, ff/Ff, and Bb carriers was more responsive to vitamin D supplementation than in those with FF/ff and tt genotypes. Other subgroups might gain less from vitamin D3 supplementation.

Association Between Hypovitaminosis D in Elderly Women and Long- and Short-Term Mortality-Results from the Osteoporotic Prospective Risk Assessment Cohort

OBJECTIVES

To investigate the association between low vitamin D levels (<50 nmol/L) and 10-year mortality in women aged 75 and older.

DESIGN

Prospective with 15 years of follow-up.

SETTING

Malmö, Sweden.

PARTICIPANTS

Population-based cohort of 75-year-old women (N = 1,044).

MEASUREMENTS

Serum 25-hydroxyvitamin D (25(OH)D) levels at age 75 (n = 1,011), 80 (n = 642), and 85 (n = 348) were categorized as low (<50 nmol/L), intermediate (50-75 nmol/L) and high (>75 nmol/L) at all ages. Hazard ratios (HRs) for all-cause mortality between ages 75 and 90 were calculated according to 25(OH)D category.

RESULTS

Between ages 80 and 90, all-cause mortality (HR = 1.8, 95% confidence interval (CI) = 1.3-2.4, P < .001; adjusted for comorbidities (aHR) = 1.9, 95% CI = 1.4-2.6, P < .001) was significantly higher in women with low 25(OH)D levels than in those with high levels. Osteoporosis had the greatest effect on mortality, but even after excluding women with osteoporotic fracture during the risk of dying associated with low 25(OH)D remained greater (HR = 1.8, 95% CI = 1.2-2.7, P = .002; aHR = 1.7, 95% CI = 1.2-2.5, P = .006).

CONCLUSION

In this observational study of women aged 75 and older, 25(OH)D levels of less than 50 nmol/L were associated with greater all-cause mortality for up to 10 years. This difference was at least partially independent of comorbidities and fracture, indicating that low 25(OH)D not only is an indicator of impaired health, but also plays a role in disease outcome.

Leisure-time physical activity and circulating 25-hydroxyvitamin D levels in cancer survivors: a cross-sectional analysis using data from the US National Health and Nutrition Examination Survey

OBJECTIVES

Circulating 25-hydroxyvitamin D (25-OHD) is associated with improved cancer prognosis in some studies, yet it may be a surrogate marker for physical activity. We investigated the associations of leisure-time physical activity (LTPA) with circulating 25-OHD levels in cancer survivors, and determined whether associations differ by indoor and outdoor activity.

DESIGN

Cross-sectional study.

SETTING

The US National Health and Nutrition Examination Survey (NHANES).

PARTICIPANTS

Cancer survivors with available data on demographic information, measures of adiposity, smoking history, self-reported LTPA and circulating 25-OHD levels in five waves of NHANES (2001-2010).

MAIN OUTCOMES MEASURES

Circulating 25-OHD levels.

RESULTS

Multivariable linear regression and logistic regression models were used to evaluate the associations of self-reported LTPA with 25-OHD, adjusting for potential confounders. Due to the differences in LTPA measure, the analyses were conducted separately for 2001-2006 and 2007-2010 data. We further estimated associations by indoor and outdoor activity in the 2001-2006 data. There were 1530 cancer survivors (mean age=60.5 years, mean body mass index=28.6 kg/m2). The prevalent cancer sites were breast (19.3%), prostate (18.8%), cervix (10.4%) and colon (8.6%). Compared with inactive cancer survivors, being physically active was associated with higher circulating 25-OHD levels (8.07 nmol/L, 95% CI 4.63 to 11.52) for 2001-2006 data. In the mutually adjusted model, higher outdoor activity (5.83 nmol/L, 95% CI 1.64 to 10.01), but not indoor activity (2.93 nmol/L, 95% CI -1.80 to 7.66), was associated with statistically significantly higher 25-OHD levels. The interaction between indoor and outdoor activities was, however, not significant (p=0.29). The only statistically significant association seen in the 2007-2010 data was among obese cancer survivors.

CONCLUSION

Physical activity, particularly outdoor activity, is associated with higher 25-OHD levels in cancer survivors. In view of the possible beneficial effects of vitamin D on cancer prognosis, engaging in outdoor physical activity could provide clinically meaningful increases in 25-OHD levels among cancer survivors.

Serum 25-hydroxyvitamin D level, chronic diseases and all-cause mortality in a population-based prospective cohort: the HUNT Study, Norway

OBJECTIVE

To investigate the association of vitamin D status with all-cause mortality in a Norwegian population and the potential influences of existing chronic diseases on the association.

DESIGN

A population-based prospective cohort study.

SETTING

Nord-Trøndelag County, Norway.

PARTICIPANTS

A random sample (n=6613) of adults aged 20 years or older in a cohort.

METHODS

Serum 25-hydroxyvitamin D (25(OH)D) levels were measured in blood samples collected at baseline (n=6377). Mortality was ascertained from the Norwegian National Registry. Cox regression models were applied to estimate the HRs with 95% CIs for all-cause mortality in association with serum 25(OH)D levels after adjustment for a wide spectrum of confounding factors as well as chronic diseases at baseline.

RESULTS

The median follow-up time was 18.5 years, during which 1539 subjects died. The HRs for all-cause mortality associated with the first quartile level of 25(OH)D (<34.5 nmol/L) as compared with the fourth quartile (≥58.1 nmol/L) before and after adjustment for chronic diseases at baseline were 1.30 (95% CI 1.11 to 1.51) and 1.27 (95% CI 1.09 to 1.48), respectively. In the subjects without chronic diseases at baseline and with further exclusion of the first 3 years of follow-up, the corresponding adjusted HR was 1.34 (95% CI 1.09 to 1.66).

CONCLUSIONS

Low serum 25(OH)D level was associated with increased all-cause mortality in a general Norwegian population. The association was not notably influenced by existing chronic diseases.

Vitamin-D concentrations, cardiovascular risk and events - a review of epidemiological evidence

Vitamin D has long been established as an elemental factor of bone physiology. Beyond mineral metabolism, the expression of the vitamin D receptor has been identified throughout the cardiovascular (CV) system. Experimental studies showed beneficial effects of vitamin D on heart and vessels, but vitamin D intoxication in animals also led to hypercalcemia and vascular calcification. Our knowledge has been extended by epidemiological studies that showed that 25-hydroxyvitamin D (25(OH)D) levels are inversely associated with an increased CV risk itself, but also with established CV risk factors, such as arterial hypertension, endothelial dysfunction and atherosclerosis. Conversely, randomized controlled trials could not document significant and consistent effects of vitamin D supplementation on CV risk or events. Potential explanations may lie in differences in reference ranges or the possibility that low vitamin D in CV disease is only an epiphenomenon. In the latter case, the key question is why low 25(OH)D levels are such a strong predictor of health. While we wait for new data, the current conclusion is that vitamin D is a strong risk marker for CV risk factors and for CV diseases itself.